Learning disabilities are not a singular disorder but a group of varied and often multidimensional disorders.¹ Difficulties in learning may manifest themselves in various combinations of impairments in language, memory, visual-spatial organization, motor function, and the control of attention and impulses.²^,³ The characteristics of a child with a learning disability are often diverse and complex. Each child presents a different composite of system problems/impairments, functional deficits, preventing participation in activities and societal limitations.

The most commonly recognized performance difficulties in learning are associated with academic success. Fletcher and colleagues ⁴ argued that learning disabilities should be characterized as “unexpected” because the child is not learning up to expectations despite adequate instruction. Typically the areas of deficits are observed in verbal learning, including difficulties with reading, the acquisition of spoken and written language, and arithmetic. Impairments in nonverbal learning are equally important and more recently recognized. The three primary areas affected by nonverbal learning disorders include visual-spatial organization, social-emotional development, and sensorimotor performance.⁵ Accompanying behavioral manifestations may include problems with self-regulatory behaviors, such as lack of attention, hyperactivity, and poor impulse control. Difficulties in social perception and social interactions may also be observed.⁵^,⁶ These learning and behavioral difficulties may be isolated (e.g., academic, motor, or behavioral), combined (e.g., academic and motor), or global (academic, motor, and behavioral).⁷ In addition to verbal and nonverbal disabilities, specific motor impairments also can be present and affect academic achievement or daily life tasks.⁸^,⁹

Definition

The heterogeneity of persons with learning disabilities has made consensus on a single definition difficult. Many disciplines describe learning disabilities according to their own frames of reference. Medical professionals tend to relate the deficit to its cause, particularly to cerebral dysfunction. Terms historically used include brain injured,¹⁰ minimal brain dysfunction,² and psychoneurological disorder,¹¹ all implying a neurological cause for the deviation in development. Educational professionals, however, prefer to describe the child’s difficulties in behavioral or functional terms. Educators view children with learning disabilities as “children who fail to learn despite an apparently normal capacity for learning.”¹² Current terminology within the academic environment includes reading disorder, mathematics disorder, disorder of written expression, and intellectual disabilities (formerly called mental retardation).¹³^,¹⁴ The lack of consensus for one accepted definition continues to affect consistency in diagnosis, research, and intervention for persons with learning disabilities.

After multiple revisions, the National Joint Committee on Learning Disabilities (NJCLD), which represents several professional organizations, proposed the following definition:

Learning disability is a general term [for a condition] that:

Is intrinsic to the individual . . . [the term] refers to a heterogeneous group. (Each individual with learning disabilities presents with a unique profile of strengths and weakness.)

Results in significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities. (These difficulties are evident when appropriate levels of effort by the student do not result in expected performance, even when provided with effective instruction.)

Is presumed to be due to central nervous system dysfunction and may occur across the life span. (They persist throughout life and may change in their presentation and severity at different stages of life.)

May occur concomitantly with other impairments or other diagnoses. (For example, difficulties in self regulation and social interaction may exist separately or result from the learning disability. Individuals with attention-deficit disorders, emotional disturbances or intellectual disabilities may experience learning difficulties but these diagnoses do not cause or constitute them.)

Is not due to extrinsic factors. (Such as insufficient or inappropriate instruction, or cultural differences.)¹⁵

This definition identifies a proposed cause but does not provide a clear exclusion statement regarding what learning disabilities may not result from. A positive component of this definition is the lifelong nature of the condition. Also, by including the behavioral manifestations of regulatory and social difficulties, a more complete picture of functional problems for the individual with learning disabilities is presented. This could assist in the creation of more comprehensive and life-spanning programs of service and ultimately help in the recognition and remediation of functional and societal limitations.

The definition used in educational settings was initially passed in Public Law 94-142 and later incorporated into the Individuals with Disabilities Education Act (IDEA) (Section 602.26).

Children with learning disabilities are defined by IDEA as follows:

Individuals with a disorder in one or more of the basic psychological processes involved in understanding or using spoken or written language. (This emphasizes the receptive and expressive difficulties a student may demonstrate.)

Those who are experiencing difficulties in the ability to listen, think, speak, read, write, spell, or do mathematical calculations. (These highlight the academic difficulties the student may experience.)

Those who may have conditions such as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia.

Those who have a learning problem that does not result from other disabilities such as motor deficits, emotional disturbances, or environmental, cultural, or economic differences.

This description does not specifically address cause but does highlight psychological processes versus neurological impairments. The primary disability focus is on language, which may exclude difficulties in learning that involve nonverbal reasoning. This definition does not mention regulatory, reasoning, and social perception difficulties that may contribute to understanding the student’s complete profile. On a foundational level this definition formed the basis for creating academic programs and delineating appropriate services for children with learning disabilities.

IDEA mandates that all children will have free and appropriate education and authorizes aid for special education and educationally relevant services for children with disabilities. IDEA influences how children with learning disabilities are identified and classified. The 1997 amendments of IDEA, by promoting the early identification and provision of services, redirected the focus of special education services by adding provisions that would enable children with disabilities to make greater progress and achieve higher levels of functional performance.¹⁶

The IDEA 2004 amendments eliminate a previous requirement that students must exhibit a severe discrepancy between intellectual ability and achievement for eligibility. This “severe discrepancy” policy often mandated that children would have to experience failure for several years to demonstrate the requisite degree of discrepancy.¹⁷ The current goal is to identify ways of serving students more quickly and efficiently once they begin to show signs of difficulty.¹⁷ Congress also indicated specifically that (1) IQ tests could not be required for the identification of students for special education in the learning disabilities category, and (2) states had to allow districts to implement identification models that used Response to Instruction (RTI).¹⁸ The RTI models suggest that the learning difficulty may be intrinsic to the child, inherent in the instruction, or a combination of both. The models propose systematically altering the quality of instruction and repeatedly measuring the child’s response to that instruction. Inferences can then be made about the child’s deficits contributing to learning difficulties.¹⁹

IDEA 2004 also limits the schools from finding a student eligible for special education services if the learning problems are determined to be caused by a lack of appropriate instruction. The law now encourages schools to use scientific, research-based interventions to maximize a student’s opportunity for success in the general education setting (least restrictive environment [LRE]) before being placed in special education. IDEA encourages educators to stress the importance of identifying individual differences and patterns of ability within each child and adjust the educational methods accordingly. Academic achievement relies heavily on the effectiveness of the teacher and the instructional techniques. Studies indicate that learning disabilities do not fall evenly across racial and ethnic groups, with a higher incidence of special education services needed for black, non-Hispanic children.²⁰ The No Child Left Behind Act challenges states and school districts to become more accountable for improving educational standards by intensifying their efforts to close the achievement gap between underachieving students and their peers.

Classifications

The two most widely used classification systems are those of the American Psychiatric Association (Diagnostic and Statistical Manual of Mental Disorders [DSM])²¹ and the World Health Organization (WHO) (International Classification of Diseases [ICD]).²² Educational professionals prefer the DSM classification for its academic relevance. A variety of specific academically related disorders are outlined in the DSM. The latest edition, DSM-IV-TR, classifies learning disabilities under “disorders usually first diagnosed in infancy, childhood, or adolescence.” It subclassifies disorders into the following categories:

Learning Disorders

Reading disorder

Mathematics disorder

Disorder of written expression

Motor Skills

Developmental coordination disorder

Communication Disorders

Expressive language disorder

Mixed receptive-expressive disorder

Phonological disorder

Stuttering

The classification system commonly used by therapists is the ICD. The ICD codes are state mandated diagnostic codes used for billing and information purposes. In the recently revised ICD-10 the category “specific delays in development,” which included “other specific learning difficulties,” was changed to “disorders of psychological development.” The term “learning” is no longer part of this classification. This updated classification is as follows:

Disorders of Psychological Development

Including specific developmental disorders (SDD) of speech and language (including acquired aphasia with epilepsy)

SDD of scholastic skills

SDD of motor function

Pervasive developmental disorder

Model of disablement

Beyond classifying learning disabilities as a diagnosis, the National Center for Medical Rehabilitation Research (NCMRR)²³ and WHO have integrated related approaches to classify functional performance. This conceptual approach, the Model of Disablement, describes the multiple dimensions of disability and identifies various internal and external factors that affect the way a disability manifests. The purpose of this model is to shift classification of a disability to include assessment of functional performance and societal participation as opposed to solely identifying component deficit areas.

Five dimensions are outlined in the Model of Disablement. They include pathophysiology, impairments, functional limitations, disabilities, and societal limitations. Pathophysiology refers to the underlying disease or injury processes at the tissue or cellular level. Proposed causative factors related to learning disabilities at this level include brain damage, biochemical abnormalities, genetics, and metabolic disorders. The challenge for interventionists is to recognize the signs and symptoms that confirm the diagnosis.²⁴

The second dimension, impairment, includes the organ and system dysfunction that potentially has a negative effect on functional performance. Children with learning disabilities may demonstrate impaired balance, endurance, and coordination of movements. Impairments that occur in one or more systems may lead to functional limitations, the third dimension. The challenge for the clinician is to treat impairments within the context of daily functional performance because impairments do not always result in functional limitation.

Functional limitations involve whole-body functions that are typically assessed but may or may not receive remediation.²⁴ For a child with learning disabilities this may include poor hand function in the performance of manipulation activities involved in dressing and handwriting. When persistent functional limitations are not remediable and cannot be adequately compensated for with assistive technology or other supports, disabilities in daily life occur. The child then fails to be an active participant in life roles, such as activities of daily living and school tasks. Emotional difficulties, such as depression and decreased self-esteem, which may result from learning difficulties, can ultimately impair social interactions.

Community and environmental barriers, called societal limitations, also can lead to restriction in social participation. An example of structural or attitudinal barriers that prevent optimal participation in society is a child who cannot use playground equipment because of lack of accessibility. The ultimate goal for the clinician is to facilitate functional abilities and performance as well as provide necessary supports so the child can become an active participant in society.

The Model of Disablement proposes that the environment, purpose, and level of participation should all be considered when evaluating performance. Determination of the presence, severity, or kind of disability should be made on the basis of a combination of these factors. Within this framework, a clinician does not assume that a handicap exists because of an impairment but rather considers levels of functional and societal abilities. This allows the therapist to determine intervention needs based on functional performance in relevant environments rather than being driven purely by diagnosis. A 9-year-old child with learning disabilities, for example, might have impairments in motor components of muscle strength and balance. Although these impairments can be identified on assessment, the Model of Disablement suggests that a disability does not exist unless these deficits affect functional performance (e.g., ascending and descending stairs) and limit societal participation (e.g., child cannot leave house independently to go to school or play). The identified impairments, based on assessment in an academic setting, would have to affect participation within the educational environment (be educationally relevant) to warrant intervention.

Incidence and prevalence

Current data indicate that 15 million children nationwide have been diagnosed with some kind of learning disability.²⁵ According to a 2007 report to Congress on the implementation of IDEA, nearly 2.6 million students aged 6 to 21 years are receiving special education services for specific learning disabilities. As of 2007, this represents 44% of students with disabilities nationwide.²⁵ Children with specific learning disabilities represent the highest incidence (number of new cases identified in a given period) among 13 disability categories, representing 44% of the total population of children receiving special education. Overall, the estimated prevalence (total number of cases in a population at a given time) of learning disabilities is approximately 15% of the U.S. population, which translates to one out of seven people.⁹ In children under age 18 years, 8% to 10% of the population have some type of learning disability.²⁶ Boys are more likely than girls to be identified as having a learning disability. According to Child Trends, 10% of boys and 6% of girls aged 3 to 17 years had a learning disability in 2004.²⁷

Perspectives on the causes of learning disabilities

Learning disability is a diverse diagnosis with varied manifestations; therefore searching for a single cause would be inadequate. Historically, researchers have studied causative factors including (1) brain damage or dysfunction caused by birth injury, perinatal anoxia, head injury, fetal malnutrition, encephalitis, and lead poisoning; (2) allergies; (3) biochemical abnormalities or metabolic disorders; (4) genetics; (5) maturational lag; and (6) environmental factors, such as neglect and abuse, a disorganized home, and inadequate stimulation.28–30

Current sources agree that possible causes of learning disabilities can include problems with pregnancy and birth (e.g., drug and alcohol use, low birth weight, anoxia, and premature or prolonged labor), and incidents occurring after birth (e.g., head injuries, nutritional deprivation, and exposure to toxic substances such as lead).31–34 Genetic and hereditary links also have been observed, with learning difficulties often seen across generations within families.³⁴ The emotional and social environment have also been considered as a contributing factor to learning disabilities.¹⁴

Children with learning disabilities frequently display a composite of neuropsychological symptoms that interfere with the ability to store, process, or produce information. These symptoms typically include disorders of speech, spatial orientation, perception, motor coordination, and activity level. Researchers have attempted to identify areas of the brain that may be responsible for these functional limitations. Tools being used include empirical measures of physiological function such as electroencephalography, event-related potentials (ERPs), brain electrical activity mapping (BEAM), regional cerebral blood flow (rCBF), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI). These measures expand the understanding of brain functioning but are best used in conjunction with data on functional and behavioral manifestations.

Research findings on brain structure have documented that certain functions are specialized within each hemisphere and this specialization is optimal for efficient learning.³⁵^,³⁶ The left hemisphere processes information in a sequential, linear fashion and is more proficient at analyzing details. Academically, this hemisphere is responsible for recognizing words and comprehending material read, performing mathematical calculations, and processing and producing language.

The right hemisphere processes input in a more holistic manner, grasping the overall organization or the “gestalt” of a pattern.³⁷^,³⁸ This type of organization is advantageous for spatial processing and visual perception. Functionally, the right hemisphere synthesizes nonverbal stimuli, such as environmental sounds and voice intonation, recognizes and interprets facial expressions, and contributes to mathematical reasoning and judgment. Over time these differences in left and right brain processing have become accepted and are commonly labels of cognitive style (i.e., left-brained versus right-brained learner).

A strict left-right dichotomy is oversimplified because it does not take into account many aspects of functional brain organization.³⁷^,³⁹ Both hemispheres must work together for a variety of specific academic outcomes such as reading and mathematical concepts. In addition to the communication that occurs between the hemispheres via the corpus callosum, essential communication within the hemispheres is also present. Intrahemispheric communication is critical for developing higher level cognitive functions such as memory, language, visual-spatial perception, and praxis.⁴⁰ Research suggests that children with learning disabilities show different patterns of cerebral organization than normal children.³⁷^,³⁹ However, brain plasticity is the basis for designing and implementing a variety of intervention techniques aimed at improving processing.

Subgroups

In early attempts to classify learning disabilities, Denckla and Rudel ⁴¹ determined that approximately 30% of the 190 children they assessed by neurological examination could be classified into three recognizable subgroups. The other 70% exhibited an unclassifiable mixture of signs. Of the 30%, the first subgroup was classified as children having a specific language disability. These children, who were failing reading and spelling, showed a pattern of inadequacy in repetition, sequencing, memory, language, motor, and other tasks, all of which require rote functioning. The second group had a specific visual-spatial disability. These children had average performance in reading and spelling with delayed arithmetic, writing, and copying skills. The children in this subgroup all had social and/or emotional difficulties. The third group manifested a dyscontrol syndrome. These children had decreased motor and impulse control, were behaviorally immature, and were average in language and perceptual functioning.

Grouping children with learning disabilities based on patterns of academic strengths and weakness is as important as grouping them based on neuropsychological or cognitive measures. With an academic classification the heterogeneity of learning disabilities can be more clearly recognized and learning modalities can be adjusted to the individual child. A child with a specific reading difficulty, for example, could be experiencing deficits in word recognition, fluency, or comprehension. Through identification of the specific areas of weakness in reading, intervention can be individualized to improve academic performance.⁴

Based on historical and current trends the following general subgroups will be explored: verbal learning impairments, nonverbal learning disabilities (NVLDs), motor coordination deficits, and social and emotional challenges.

Verbal learning impairments

Verbal learning impairments typically include dyslexia, dyscalculia, and dysgraphia. Harris ¹³ classifies these deficits in functional terms, with dyslexia including disorders of reading and spelling, dyscalculia denoting a mathematics disorder, and dysgraphia describing a disorder of written expression. These learning disorders may occur individually or concurrently. Each of these verbal learning impairments will significantly influence academic performance.

Dyslexia (developmental reading disorder).

Dyslexia is a learning impairment in which the ability to read with accuracy and comprehension is substantially less than expected for age, intelligence, and education and that impairs academic achievement or daily living.²¹ The International Dyslexia Association adopted the following definition in 2002: “Dyslexia is a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede the growth of vocabulary and background knowledge.”⁴²

Characteristics of dyslexia include the following ⁴³^,⁴⁴:

Difficulty learning to recognize written words

An inability to sound out the pronunciation of an unfamiliar word

Seeing letters or words in reverse (b for d or saw for was)—although seeing words or letters in reverse is common for children younger than 8 who do not have dyslexia, children with dyslexia will continue to see reversals past that age

Difficulty comprehending rapid instructions or following more than one command at a time

Problems remembering the sequence of things, such as learning the order of the alphabet or spelling

Difficulty distinguishing between similar sounds in words; mixing up sounds in multisyllable words (auditory discrimination) (e.g., aminal for animal, bisghetti for spaghetti)

Slow or inaccurate reading, with difficulty reading out loud

Difficulty rhyming

Dyslexia is the most common learning disorder, affecting as many as 80% of individuals identified as learning disabled.⁴⁵ Prevalence rates range from 10% to 15% of the school-aged population,⁴⁶ with the highest noted estimate of 17.4%.⁴⁷ Historically, dyslexia was considered more common in boys than in girls, but data indicate an equal distribution between the sexes.⁴⁸ Boys are more likely to act out as a result of having a reading difficulty and are therefore more likely to be identified early. Girls, on the other hand, are more likely to try to “hide” their difficulty, becoming quiet and reserved.¹⁸

Causes of dyslexia can be both genetic and neurobiological.¹⁴^,¹⁸^,⁴² Genetic causation has been linked to chromosomes 1, 2, 3, 6, 11, 13, 15, and 18.⁴⁹ There is a strong inheritability of the genetic links for dyslexia. Statistics suggest that 30% to 50% of children with dyslexia have a parent with the disorder.⁵⁰ Neuroanatomical abnormalities, atypical brain symmetry, and disruptions in neural processing have been observed in children with reading disorders.¹⁴^,¹⁸^,⁴⁸^,⁵¹ Anatomically, the measurements that best discriminate between children with and without dyslexia are the right anterior lobe of the cerebellum and the area involving the inferior frontal gyrus of both hemispheres.¹⁸ Dynamic investigations using functional brain imagining techniques (PET, fMRI, and the newer ultrafast echo planar imaging [EPI]) are providing significant information on brain functioning during cognitive tasks such as reading and picture naming.¹⁴^,⁴⁸

Reading skills consist of a combination of visually perceiving whole words and phonetically decoding letters, morphemes, and words.⁵² Individuals with reading disorders exhibit brain activation patterns that provide evidence of an imperfectly functioning system for segmenting words into phonological (language) parts and linking the visual representations of letters to the sounds they represent.⁴⁷ These disruptions of the posterior reading system result in increased reliance on ancillary systems during reading tasks, including the frontal lobe and right hemisphere posterior circuitry. This suggests that the child with dyslexia may be compensating for poor phonological skills with other perceptual processes, helping to explain why individuals with dyslexia can develop reading skills, although they often remain slow and nonautomatic.⁴⁸

Dyscalculia (mathematics disorder).

Dyscalculia is a learning impairment in which mathematical ability is substantially less than expected for age, intelligence, and education and that impairs academic achievement or daily living.²¹ Difficulties occur with comprehending a variety of math concepts, including number quantities, money, time, and measurement. This disorder also involves difficulties with computations and problem solving of specific math functions, which affects the ability to understand, remember, or manipulate numbers or number facts.¹⁸ This heterogeneous disorder may involve both intrinsic and extrinsic factors.⁵³ Intrinsic factors are hypothesized to include deficits in visual-spatial skill, quantitative reasoning, sequencing, memory, or intelligence. Extrinsic factors can be a combination of poor instruction in the mastery of prerequisite skills as well as attitude, interest, and confidence in the subject.

Characteristics of dyscalculia include the following ⁵⁴:

Confusing numbers and math symbols (+, −, ×, ÷)

Inconsistent ability in addition, subtraction, multiplication, and division

Problems sequencing numbers, or transposing them when repeated

Difficulty with abstract concepts of time and direction

Poor mental math ability

Difficulty with money, budgeting, balancing checkbooks, and financial thinking (e.g., checking change or estimating the cost of items in a shopping basket)

Problem reading analog clocks

Trouble keeping score during games and playing games with flexible rules of scoring such as poker

Prevalence of dyscalculia is 5% to 6% in the school-aged population, with a nearly equal male-to-female ratio.¹⁴^,⁵⁵ Geary⁵⁶ concludes that individuals with arithmetic disabilities currently appear to constitute at least two subgroups: those with only mathematic disorders and those with concomitant reading disorders and/or attention-deficit disorder.

Although there is evidence that this disorder is familial and heritable, much less research on its cause is provided than on the causes of most other learning disorders. Dyscalculia shares genetic influences with reading and language measures. The association between dyslexia and dyscalculia seems to be largely genetically mediated.¹⁴^,⁵⁵ Other risk factors for development of dyscalculia include prematurity and low birth weight. In addition, environmental deprivation, poor teaching, classroom diversity, and untested curricula have been linked to cause.⁵⁵

The neurological cause of dyscalculia was initially hypothesized to be right hemisphere dysfunction because of the strong relation of visual-spatial skills to numerical computation.⁵⁷ Additional research supports the involvement of both hemispheres because mathematics computation involves a complex relation of spatial problem solving, sequential analysis, language processing, and memory.⁵⁵ Specifically involved are portions of the parietal and frontal lobes.¹⁴ In an effort to compensate, individuals with dyscalculia can recruit alternate brain areas, but this substitution often results in inefficient cognitive functioning.⁵⁵

Dysgraphia (disorder of written expression).

Dysgraphia is a learning impairment in which writing ability is substantially less than expected for age, intelligence, and education that impairs academic achievement or daily living.²¹ The DSM, fourth edition (DSM-IV) diagnosis of “disorder of written expression” depends on recognition of “writing skills substantially below those expected given the person’s chronological age, measured intelligence, and age appropriate education” that “significantly interferes with academic achievement or activities of daily living that require composition of written texts.”²¹ Children with dysgraphia have specific difficulties in the ability to write, regardless of the ability to read. This may include problems using words appropriately, putting thoughts into words, or mastering the mechanics of writing. Classifications of dysgraphia can include penmanship-related aspects of writing (e.g., motor control and execution), linguistic aspects of writing (e.g., spelling and composing), or a combination.⁵⁸ This heterogeneous disorder is frequently found in combination with other academic, learning, and attention disorders.¹³^,¹⁸

Characteristics of dysgraphia include the following ⁵⁹:

Poor legibility: irregular letter size and shapes, poor spacing

Mixing uppercase and lowercase letters; unfinished letters

Spelling difficulties

Fatigues quickly or complains of pain when writing

Decreased or increased speed of copying or writing

Needs to say words out loud while writing

Struggles with organizing thoughts on paper

Difficulty writing grammatically correct sentences and organized paragraphs

Large gap between knowledge base and ability to express ideas in writing

Awkward pencil grip

Limited data are available on the prevalence of dysgraphia. Although 10% to 30% of school-aged children struggle with handwriting, we cannot assume they have been diagnosed with dysgraphia.⁶⁰ Difficulties in written expression are frequently underidentified and can be masked by reading disorders or considered to be attributable to poor motivation. Studies have suggested that dysgraphia may be as common as reading disorders and may occur in 3% to 4% of the population.¹³^,⁵⁸

Dysgraphia has been suggested to be a neurological processing disorder that seldom occurs in isolation and can result from a number of other dysfunctions, including attention deficit, auditory or visual processing weakness, and sequencing problems.¹⁴^,⁶¹ The complex nature of written expression makes finding the cause difficult. Writing involves integration of spatial and linguistic functions, planning, memory, and motor output. This suggests involvement of both the left and right hemispheres for skill in decoding, spelling, formulating and sequencing ideas, and producing work in correct spatial orientation, all coupled with rules of punctuation and capitalization.

Nonverbal learning disability

NVLDs (or NLDs) are considered by some to be a neuropsychological disability. Although this condition has been identified for more than 30 years, it has not yet been included as a diagnostic category in the DSM.⁶² The pioneer in the field, Dr. Byron P. Rourke, first identified in 1985 this separate and distinct learning disability. In 1995 he defined nonverbal disability as “a dysfunction of the brain’s right hemisphere—that part of the brain which processes nonverbal, performance-based information, including visual-spatial, intuitive, organizational and evaluative processing functions.”⁶³ Nonverbal learning disorders affect both academic performance and social interactions in children. Three primary areas affected by NVLDs include visual-spatial organization, sensory-motor integration, and social-emotional development. The social and emotional difficulties for individuals with nonverbal learning disorders are paramount, leading some researchers to label this a social-emotional learning disability.¹³^,⁶⁴ NVLDs are generally identified by a distinct pattern of strengths and deficits, with excellent verbal and rote memory skills and poorly developed sensory-motor and graphomotor ability, executive functioning, and social interactions.¹³^,⁶⁵^,⁶⁶

Characteristics of NVLDs include the following ¹⁴^,⁶²^,⁶⁷:

Higher verbal IQ compared with performance (nonverbal) on the Wechsler Intelligence Scale for Children (WISC)

Develops speech, language, and reading skills early

Strong vocabulary and spelling

Ability to memorize and repeat a massive amount of information provided it is in spoken form

Learns better and faster through hearing information rather than seeing it

Difficulties with constructional and spatial planning tasks

Fine and gross motor difficulties affecting printing and cursive writing, physical coordination, and balance

May exhibit limited facial expression, flat affect, unchanging voice intonation, and robotic speech

Poor interpretation of emotional responses made by others

Trouble reading and understanding facial expressions, gestures, and voice intonations

Nuances of spoken language, such as hidden meanings, figures of speech, jokes, and metaphors are interpreted on a concrete level

Struggles with conversation skills, dealing with new situations, and changing performance in response to interactional cues

Difficulties in problem solving and understanding cause-effect relationships

Poor awareness of social space

Can be intrusive and disruptive

NVLDs make up 5% to 10% of all individuals with learning disabilities.⁶⁸ NVLD is frequently overlooked in the educational arena because children with this disorder are highly verbal and develop an extensive vocabulary at a young age. Well-developed memory for rote verbal information positively influences early academic learning of reading and spelling. Yet these students will have difficulty performing in situations where adaptability and speed are necessary, and their written output will be slow and laborious.⁶⁵ Nonverbal learning disorders are therefore challenging to identify at younger ages but become progressively more apparent and debilitating by adolescence and adulthood. The challenges in early identification, the absence from the DSM-IV, and the different views held by psychological and educational disciplines often result in lack of awareness of, accurate diagnosis of, and appropriate service provision for these students.

Little is known about possible genetic or environmental causes of NVLD. There are no family, twin, adoption, segregation, or linkage studies available.¹⁴ Pennington¹⁴ proposes that both Turner syndrome and fragile X syndrome in females appear to be possible genetic causes of NVLD. Similarities include deficits in executive functions, increased difficulties in math versus reading and spelling, functional structural language but impaired pragmatic language, and social anxiety and shyness.¹⁴ Differential diagnosis is essential because NVLD can occur in conjunction with dyscalculia, attention deficit, adjustment disorder, anxiety and depression, emotional disturbances, and obsessive-compulsive tendencies.

Motor coordination deficits

Children with learning disabilities may or may not manifest motor coordination problems. Conversely, some children have motor and coordination problems but do not experience learning difficulties. Children with motor deficits typically have difficulty acquiring age-appropriate motor skills and move in an awkward and clumsy manner. Difficulties in daily functional tasks and performance areas (e.g., school and leisure skills) are common. Motor deficits can result from a wide variety of neurological, physiological, developmental, and environmental factors. These impairments can manifest in diverse ways depending on the severity of the disorder and the areas of motor and social performance affected. This will be discussed at length in the next section.

Social and emotional challenges

Behavioral patterns or disorders associated with learning disabilities include frustration, anxiety, depression, attention deficits, conduct problems, and global behavior problems. Ames ⁶⁹ stressed that no single behavior pattern is prevalent in children with learning disabilities. Children with learning disabilities not only struggle in the classroom, but experience difficulties in the social arena as well.⁷⁰ Issues in learning and related behaviors affect one another in a complex manner, leaving us to wonder which is the cause and which is the symptom.

Frustration, deflated self-esteem, and other social and emotional difficulties tend to emerge when instruction does not match learning styles.⁷¹ This frustration mounts as the child notices classmates surpassing them, and this often results in exasperation with trying to keep up. The pressure then becomes for the child to “try harder,” when ironically most do not understand just how hard the child is trying. The dissatisfaction in not meeting the teacher’s expectations is often overshadowed by the inability to succeed in personal goals and a lack of self-worth. This can result in the development of internal perfectionism to deal with the lack of competence, with the belief of the child that he or she should not make mistakes.⁷²

Anxiety is another response that may occur with persistent difficulties in understanding and successfully completing schoolwork. This occurs when the child feels out of control and lacks the ability to plan and execute strategies for success.⁷¹ The mismatch between ability, expectations, and outcomes can cause frustration, disappointment, and stress, triggering a range of emotions and behaviors that interfere with everyday functioning in multiple environments.⁷¹

Other emotional difficulties are noted in attention. When a lesson is taught in a manner that is too complex, the child may become inattentive. Attention problems can influence behavior, often relating to difficulties with impulse control, restlessness, and irritability, affecting learning and peer interactions. These issues frequently coincide with frustration, anger, and resentment, which may manifest as a conduct problem (e.g., verbal and nonverbal aggression, destructiveness, and significant difficulties interacting with peers). Children with learning disabilities often become discouraged and fearful, are less motivated, and develop negative and defensive attitudes. These patterns of behavior can worsen with age, contributing to juvenile deliquency.³ Low self-esteem and depression are common during school years and tend to escalate around age 10 years.⁷³

Poor academic progress, additional prompting needed from teachers, and negative attention for disruptive behaviors can cause children with learning disabilities to perceive themselves as being “different.”⁷⁴ Lack of success in school experiences can influence the development of positive self-perception and can have powerfully negative effects on self-esteem.⁷¹ A self-defeating cycle may be established: the child experiences learning problems, school and home environments become increasingly tense, and disruptive behaviors become more pronounced. These responses, in turn, further affect the child’s ability to learn. Lack of success generates more failure until the child anticipates defeat in almost every situation.

Assessment and intervention

Specialists

Evaluation and intervention for children with learning disabilities should involve an interdisciplinary team owing to the varied nature of presenting problems. Most children with learning disabilities are seen by a group of professionals, the makeup of which depends on the purpose, location, philosophical orientation, or availability of resources of a particular program. Box 14-1 lists the different professionals and specialists who might participate in assessment or remediation of children with learning disabilities. The types of professionals are grouped into the four categories of education, medicine and nursing, psychology, and special services; they have been listed only once, although some professions could be categorized in multiple ways.

Therapists should be familiar with the roles of the various medical specialists and of primary care physicians. Psychologists have two distinct and often separate roles in the care of children with learning disorders. The first role is in identification of learning strengths and weaknesses. Psychological testing is often essential in the recognition of specific learning problems and may be done by clinical psychologists, school psychologists, or clinical neuropsychologists who specialize in diagnosis of learning disorders. The second role of psychologists is to provide mental health services and support systems to address academic, social-emotional, and behavioral issues. Counseling and behavior management can also be provided by a psychiatrist, behavioral specialist, or social worker. School adjustment or guidance counselors offer support and advice on specific academic difficulties, social conflicts, and affective issues.

Physical educators, adaptive physical educators, physical therapists (PTs), occupational therapists (OTs), and speech therapists also may be involved in the assessment of motor deficits and related areas. Overlap in the areas assessed may occur. The unique training of each professional influences both the selection of tests and the qualitative aspects of assessment on the basis of observations of a child’s performance. Although the evaluations may appear similar, differences among professions are apparent in orientation and rationale when interpreting dysfunction.

Planning an assessment protocol can prevent unnecessary duplication of testing and provide comprehensive information related to the referral concerns. The assessment is driven by the referral concerns and the functional difficulties the child is experiencing. Communication of information between professionals and the parents will generate a comprehensive picture of the child’s areas of strength and weakness, necessary for effective intervention planning.

Coordinating multiple interventions

As the number of disciplines involved in the assessment and therapeutic management of children with learning disabilities has steadily increased, communication for effective programming has become more challenging. Despite the benefits of specific skills brought to the case by each professional, the huge variety of well-meaning recommendations can result in service delivery overkill. Case Study 14-1 provides an example of the negative impact of overabundant specialized intervention on the child and family. In this case, if all the interventionists had communicated, a more realistic and effective plan could have been developed.

CASE STUDY 14-1 MATT

Matt is an 8-year-old boy who was referred for clinic-based physical therapy intervention for 1 hour per week for remediation of severe motor coordination and planning problems that accompanied his learning disability. In addition to Matt’s weekly treatment sessions, suggestions were made to his mother for a home program to be accomplished three times a week for 15 to 30 minutes each time. Meanwhile, Matt also received other services. Although he was mainstreamed into a regular classroom in accordance with the special education law, he was seen by the resource teacher on a daily basis and by the adaptive physical education teacher twice a week to meet his specialized needs. The classroom teacher told Matt’s mother that Matt must read at least one book a night because he needed additional reading practice. A reading tutor came to Matt’s house on Saturday mornings. Ocular motor problems were identified, so he was evaluated by an optometrist, who recommended weekly visits plus ocular exercises for 30 minutes a day. Matt developed secondary emotional problems, partly because he was bright yet aware of his learning disability and frustrated by it. Thus Matt also saw a psychotherapist on a weekly basis. The psychotherapist recommended participation in weekly group sessions, in addition to Matt’s individual sessions, to help improve peer relationships. Thus Matt’s therapists had developed a 12-hour-a-day program for him and his family. It was no wonder that Matt had difficulty in developing peer relationships; he never had time. Matt’s schedule also affected interaction in his own family. His mother believed that being a “therapist” to Matt interfered with her role as his mother. She felt unable to carry out the home program and felt guilty for not doing it.

What became apparent with Matt’s case was that although each professional involved with him made an important contribution to evaluation and intervention, the massive input, to some extent, had a detrimental effect on Matt and his family. Coordinating interventions and providing additional support at home can create a drain on the family and limit time for family activities and extracurricular participation.

Effective coordination of intervention services presents a dilemma because no single discipline is specifically trained for that role.⁷⁵ Kenny and Burka⁷⁵ stress the need for a person to act as a coordinator for the management and integration of the interventions received by the child. Unfortunately, this role does not exist; therefore the parent must assume this responsibility.

School-based service delivery models

The model of service delivery for each individual child should be developed to facilitate the student’s ability to be successful in the learning environment. A continuum of services exists to enable interventionists to be responsive to all children’s needs. The continuum includes consultation, integrated or supervised therapy, and direct service.⁷⁶ Unfortunately, a lack of available resources can influence what type and frequency of services are provided. In creating a plan that truly addresses the issues hindering a child’s learning within the academic setting, the team must work together to fabricate relevant and inclusive goals.

IDEA currently requires that all children in special education be educated in the least restrictive environment. The law requires that students with disabilities be educated to the extent appropriate with their peers, within the inclusion classroom. Removing the child from the classroom for special education and intervention is discouraged unless it is absolutely necessary for the student to learn effectively. Although the model of inclusion can be effective for many children, it requires members of the team to work closely together with the regular education teacher. This collaborative effort ensures an understanding of the child’s special learning needs and incorporation of therapeutic procedures into the regular classroom to facilitate the best learning environment.

Bricker ⁷⁷ contends that adhering strictly to this model can be detrimental to certain students, and each case must be looked at individually. The least restrictive environment should be determined after assessing the specific needs of the child. If services in a regular classroom, coupled with supplemental aids and services, do not meet the needs of the child, an alternate environment should be considered. The first adaptation might be to have the child participate for the majority of the day in the regular classroom and leave for special instruction for part of the day. In some educational settings, children with learning disabilities are given full-time instruction in a special classroom with a small group of other children with learning disabilities. A special education teacher or a learning disability specialist is in charge of the classroom. The most specialized environment would be a private school only for children with learning disabilities.

Learning disabilities and motor deficits or developmental coordination disorder

Approximately half of children with learning disabilities have motor coordination problems.⁷⁸ Motor deficits are often the most overt sign of difficulty for the child with learning disabilities. Lowered academic achievement within any or all areas of learning (reading, spelling, writing) is also seen in children with developmental coordination disorder (DCD).⁸^,²¹ A study by Jongmans and colleagues⁷⁸ indicates that children with concomitant perceptual-motor and learning problems are more severely affected in motor difficulties than those with only DCD or who are only learning disabled. At times, extreme discrepancy in competence over a range of motor skills exists, with strengths in some motor areas and significant weaknesses in others. Presentation of difficulties may change over time depending on developmental maturation, environmental demands, and interventions received.

An International Consensus Meeting on Children and Clumsiness was held in 1994 with expert educators, kinesiologists, OTs, PTs, psychologists, and parents. These experts discussed a common name to identify “clumsy” children with movement, coordination, and motor planning difficulties. The term developmental coordination disorder (DCD), as first described in DSM-III,²¹ was identified to distinguish these children from those with severe motor impairments (such as those with cerebral palsy or paraplegia) and children with normal motor movements. A child with DCD often exhibits difficulty with motoric academic tasks such as handwriting and gym class, self-care skills such as dressing and using utensils, and leisure activities including playground games and social interactions.⁷⁹

Definition

As described in the DSM-IV-TR ²¹ as one of the motor skill disorders, DCD has the following criteria:

A marked impairment in the development of motor coordination (criterion A)

An impairment that significantly interferes with academic achievement or activities of daily living (criterion B)

The presence of coordination difficulties that are not the result of a general medical condition (e.g., cerebral palsy, hemiplegia, or muscular dystrophy); the criteria for pervasive developmental disorder are not met (criterion C)

If mental retardation is present, the motor difficulties are in excess of those usually associated with it (criterion D)

Clinical presentation

DCD is a childhood disorder characterized by poor coordination and clumsiness. Typically, there is no easily identifiable neurological disorder accompanying this lack of motor skills required for everyday life.⁸⁰ Characteristics can be seen in developmental areas such as gross motor, fine motor, visual motor, self-care, and social-emotional areas. Children tend to develop at a slower rate and require more effort and practice to accomplish age-level tasks. The salient features are coordination difficulties that include decreased anticipation, speed, reaction time, and quality and grading of movement.⁸¹^,⁸² These children often have difficulties analyzing the task demands of an activity, interpreting cues from the environment, using knowledge of past performance, and transferring and generalizing skills.⁸³

Coordination difficulties are most apparent when complex motor activities are attempted. Physical education class often presents major problems. For example, a 9-year-old boy described his motor problems as follows: “When the gym teacher tells us to do something, I understand exactly what he means. I even know how to do it, I think. But my body never seems to do the job.”⁸⁴ Case Study 14-2 describes the motor difficulties frequently encountered in children with DCD.

CASE STUDY 14-2 PAUL

The following is a mother’s description of her child, Paul, who had motor coordination problems and learning disabilities: “I think when Paul was first born I tried to ignore the problem. Paul is a child who never climbed or ran or drew pictures the way other kids did. But until he went to nursery school, I didn’t pay much attention to it. Maybe I didn’t want to pay attention to it. Maybe I knew it was there and I didn’t want to know about it. I’m not sure. But Paul was always a verbal child and a creative and imaginative child. He and I had something special because I used to enjoy that kind of creative imaginative play. We used to have our own world of various fantasies, heroes, and places.

“Paul sat up at about 7 months; he crawled and crept on time. He didn’t learn to walk until he was about 15 months old. He walked cautiously, holding on and not letting go. He walked late, but he talked early. He said his first clear word, “cat,” at 6 months. He knew what a cat was and could relate to it. My husband and I were so enthusiastic about his sounds. In those days they said that if you stimulated your child and talked to him and got him ready to talk, he could read early. I was concerned that Paul would be able to talk and have a marvelous vocabulary and read because I had a reading disability and a spelling disability.

“When Paul was 4 years old and in nursery school, at my first conference the teacher said, ‘Look out the window, Mrs. B.—see Paul sitting at the bottom? All the other kids are climbing on top of the jungle gym.’ And then she showed me some art work. Paul couldn’t cut, he couldn’t paste, he couldn’t do any of it. We could definitely, at the age of 3 or 4, see his problems. He was bright, but he couldn’t cut, paste, or draw, he couldn’t climb, and he really didn’t know how to run. That was where his handicaps were first being noticed, more by other teachers and professionals than by my husband and myself.

“When we had to make the decision as to whether to put Paul into kindergarten or hold him back, we were frustrated because Paul was very bright and very alert. He has always known everything that was going on in the world.

“Now, the kids Paul knows and the kids who know Paul know that he can’t do motor tasks and they’ll come over and play rocket ships with him. But there will come a time, as the kids are getting older, that they won’t want to do this.”

Paul’s mother, who also had learning and motor difficulties, described her own disability as follows:

“The hardest course for me was gym. I was unfortunate enough to have the same gym teacher throughout high school. The teacher always used to think I was a lazy kid, that I just never wanted to try to do the exercises. Although I tried, I couldn’t do the stunts and tumbling for anything. The other girls would do a somersault and I would still do it like a 4-year-old. I’d just about get over.

“I took dance a couple of times. I never could figure out as a kid why I couldn’t point my toes. The teacher would say, ‘Point your toes,’ and it never made any sense to me. I always curled my toes up. Only when somebody sat down with me and actually showed me did I know that that was how you were supposed to point your toes. With other kids, they just did what the teacher did. Nobody had to stop and tell them. I was the klutzy kid. I never could do the nice leaps across the floor. But I would try. After two or three sessions my mother stopped giving me lessons. She was probably embarrassed.

“As a girl, it wasn’t as traumatic not being athletic. As I got older, the need for a woman to be athletic tended to decrease, whereas for a boy, the need to be athletic and competitive tends to increase. I foresee this as one of the major problems for Paul.

“Most of my life my friendships have always relied on other people. I met most of my friends through other friends because I’ve gone along to things. I think it goes back to being teased as a child about the things I couldn’t do or the way I looked. If you looked at me, I probably looked like a lot of the learning-disabled kids that you see: my clothes were not put together properly, my shoelaces were untied, and my hair was never quite combed properly.

“It was very difficult for me to learn how to put on makeup and use a hairdryer. It would take many hours of trying to learn. For a long time, my fingernails were cut very short because I didn’t know how to file them. It is still very hard for me to put on eye makeup and look in the mirror and try to figure it out. I still don’t feel as though I am completely put together. And I put a lot of effort and energy into looking good.”

Development of gross and fine motor skills, coupled with the child’s ability to master body movements, enhances feelings of self-esteem and confidence. Through persistence in mastering the varied challenges of motor exploration the child builds self-reliance. The frustrations and accomplishments enhance confidence and the ability to take risks. By engaging in group activities children develop essential social skills, including how to compromise, work as a team, and deal with conflicts and different personality styles.

Poor motor coordination often results in significant social and emotional consequences. When a child is poorly coordinated she or he is often teased and shunned from group play. This may lead to anxiety and avoidance of participation in games, as children frequently judge themselves to be both physically and socially less competent.⁸⁵ Anxiety may be more prevalent in adolescence, most notably in boys.⁸⁶ Because they are often unsuccessful in group participation, difficulties with navigating the changing demands of cooperative play and negotiating with others and reluctance to advocate for themselves often result. Boys with learning and motor coordination problems have been found to demonstrate significantly less effective coping strategies in all domains of functioning compared with a normative sample.⁸⁷ Feelings of incompetence, depression, or frustration are common and can be lifelong problems.⁸⁸^,⁸⁹ The impact of motor coordination difficulties on social behavior is exemplified by this statement from a child with learning disabilities and motor deficits:

“They always pick me last. This morning they were all fighting over which team had to have me. One guy was shouting about it. He said it wasn’t fair because his team had me twice last week. Another kid said they would only take me if his team could be spotted four runs. Later, on the bus, they were all making fun of me, calling me a “fag” and a “spaz.” There are a few good kids, I mean kids who aren’t mean, but they don’t want to play with me. I guess it could hurt their reputation.”⁸⁴

Gross motor characteristics of DCD include the following:

Diminished core strength and postural control

Delayed balance reactions

Often falling, tripping, and bumping into things; acquiring more than the usual number of bruises

Motor movements that are performed at a slower rate despite practice and repetition ⁸²

Motor milestones that may be achieved in the later range of normal development

Poor anticipation (do not use knowledge of past performance to prepare)

Notably different quality of running and ball skills from typical peers

Difficulty learning bilateral tasks such as riding a bicycle, catching a ball, and jumping rope

Possible hesitance with and avoidance of new or complex motor tasks (e.g., playground equipment, gym class)

Possibly poor safety awareness

Inability to smoothly turn and position body when going up ladder to a slide or to get into a chair

Possible sedentary activity level; may prefer to engage in solitary play

Tendency to not play games by the rules

Often, avoidance of team sports such as T-ball and soccer

Fine motor characteristics of DCD include the following:

Diminished wrist and hand strength

Maladaptive or immature grasp patterns

Possible use of excess or not enough pressure

Poor refinement of small motor movements with hands (qualitatively, the child looks like he or she is wearing a pair of gloves when trying to manipulate small objects)

Often dropping or breaking of items

Delayed dressing skills (buttons, zippers, fasteners, shoelaces)

Trouble with eating utensils (scooping, piercing)

Difficulty with tool use (e.g., scissors, pencils, stapler, hole punches)

Writing that is laborious and often illegible

Impaired drawing ability characterized by poor motor control, with wobbly lines, inaccurate junctures, and difficulty coloring within the lines.

Decreased ability with pasting, gluing, manipulating stickers and other art materials

Difficulty with constructive, manipulative play (e.g., block building, Tinkertoys, Legos)

Often the presence of associated articulation deficits, possibly because of the fine motor nature demanded for articulation

Visual motor characteristics of DCD include the following:

Difficulty with visually guided motor actions (i.e., eye-hand and eye-foot coordination)

Hesitancy or decreased safety on stairs

Trouble with timing needed for kicking, hitting, and catching ball

Difficulty with hopscotch and four squares

Poor judgment of spatial relationships (knowing where the body is in space)

Delayed development of prepositional and directional concepts

Difficulty with spatial planning tasks such as puzzles, building models, and constructional toys

Handwriting that is often labored, with spacing and sizing problems evident; letters may be irregular, illegible, and poorly organized on the page

Self-care characteristics of DCD include the following:

Slowness to develop independence in activities of daily living

Overreliance on parents to help with self-care skills

Clothes that are often on backward or crooked

Struggles with cutting fingernails, putting on makeup, tying necktie, using a hair dryer

Difficulty blowing nose with tissue, putting on Band-Aid

Trouble putting toothpaste on toothbrush

Messy eater, spills often, does not recognize food on face

Difficulty pouring from a container, opening lunch box, unwrapping sandwich, opening containers, peeling fruit

Trouble packing a bag, backpack, or suitcase

Difficulty sequencing daily routines

Social and emotional characteristics of DCD include the following:

Often emotionally immature

May exhibit behavioral difficulties such as acting out or becoming class clown

May be more introverted and anxious

Can appear fiercely competitive, hating to lose, complaining that rules are unfair

Can be self-deprecating, calls self “stupid”

Often easily frustrated

May experience depression and feelings of incompetence

Has difficulty making and maintaining friendships, plays alone

Has feelings of low self-worth, poor self-esteem ⁹⁰

Perceived by others as lazy, overprotected, or immature ⁹¹

Adolescents may have fewer social pasttimes and hobbies than peers

Prevalence

Estimating the prevalence of children with DCD is challenging. Great variety exists in the clinical presentation, with some children exhibiting motor deficits in all areas and others having only isolated concerns. Among professionals there is a lack of clarity on the definition and diagnostic criteria.⁹¹ Overlap of symptoms associated with other conditions such as attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders, perceptual-motor problems, and speech and language impairments further complicates differential diagnosis.¹⁴^,⁸⁰^,⁹² In addition, there is no single test or screening measure that can be used to confidently identify the problem.⁹³ Other factors influencing prevalence rates include the criteria used to delineate a child with DCD from a typical peer, differences in terminology, types and methods of testing, reliability of the tests used, and heterogeneity of the test sample.⁷⁹^,⁹³^,⁹⁴

An estimated 5% to 10% of children aged 5 to 11 years had DCD.²¹ Boys diagnosed with DCD outnumber girls by two to one. This difference may reflect higher referral rates for boys as a result of increased behavioral difficulties of boys with motor incoordination.⁹⁵

Perspectives on the causes of developmental coordination disorder

There is no single explanation for the cause of DCD. Neurological dysfunction, physiological factors, genetic predisposition, and prenatal and perinatal birth factors have been proposed to explain the basis of DCD.⁹¹^,⁹⁶ It is recognized that DCD is heritable and is genetically distinct from ADHD, although the comorbidity rate is up to 50%.¹⁴ Comorbidity is high with other diagnoses, including autism spectrum disorders,⁸⁰ as well as a variety of developmental learning problems such as math disability, reading disability, specific language disabilities, spelling and writing disabilities, and so on. Correlation has also been noted between preterm infancy and low birth weight with characteristics of DCD. The heterogeneity of DCD makes finding a unitary cause difficult. Children with DCD present wide variability in both locus of specific problems and functional disabilities. Further complicating an understanding of the cause is that the intervention for the child with DCD is driven by competing treatments.⁹⁷

Few studies have been conducted to look at brain images in children with DCD, with no particular patterns of abnormality observed.⁹¹ Hadders-Algra⁹⁸ has suggested that DCD is a result of damage at the cellular level in the neurotransmitter and receptor systems, rather than a specific region of the brain. Resulting coordination difficulties can be from a combination of one or more impairments in proprioception, motor programming, timing, or sequencing of muscle activity.

Possible physiological origins of motor coordination deficits have highlighted multisensory processing. Ayres,⁹⁹ in her theory of sensory integration, suggested that the integration among sensory systems is imperative for refined motor performance in children. She proposed that normal development depends on intrasensory integration, particularly from the somatosensory and vestibular systems. Lane¹⁰⁰ outlines the role of vision, combined with vestibular and proprioceptive inputs, as a foundation to motor performance. In combination, these systems sustain postural tone and equilibrium, provide awareness and coordination of head movements, and stabilize the eyes during movement in space.

More recently, Piek and Dyck ¹⁰¹ found support for the correlations between DCD and deficits in kinesthetic perception, visual-spatial processing, and multisensory integration.¹⁰¹ In general, it is thought that reduced rates of processing information and deficits in handling spatial information may underlie the deficits in motor control.⁸⁰ Obviously more work is needed on the cause of DCD.

Subtypes of developmental coordination disorder

Various approaches have been used to investigate subtypes of DCD, including classification by underlying causes, clinical and descriptive approaches, and statistical clustering.⁹⁴ Initial attempts at classifying subtypes within DCD support the heterogeneity of this group of children.¹⁰² Work by Dewey and Kaplan¹⁰³ suggests that children with DCD may be classified into subgroups based on distinctions in motor planning and motor execution deficits. They identified three subgroups: children who exhibited deficits in motor execution alone, those whose primary deficits were in motor planning, and children who exhibited a generalized impairment in both areas.

Macnab, Miller, and Polatajko ¹⁰⁴ identified five different profiles of children with DCD. They used measures of kinesthetic acuity, gross motor skill, static balance, visual perception, and visual motor integration. Two distinct groups emerged, with children exhibiting generalized visual deficits and generalized dysfunction in all areas. Generalized gross motor deficits did not emerge as a distinct subgroup, as the third group demonstrated a discrepancy between static balance and complex gross motor tasks, and the fourth group had poor performance on running but performed well on kinesthetic acuity. Other groups included children with deficits in visual motor and fine motor problems. These results suggest that a subtype based on motor execution or planning problems alone may be too general.

Assessment of motor impairments

A variety of professionals may be involved in a comprehensive assessment of motor deficits. Pediatric OTs and PTs are often the core team assessing functional motor concerns. Areas assessed by pediatric OTs and PTs often overlap, so communication is essential to ensure that testing is not replicated. Ideally, performance will be evaluated in multiple environments and include components of skill, functional performance areas, and social and societal participation. Specific recommendations should include activities to enhance performance in the environments in which the child functions on a daily basis.

Clinical judgment of the therapist is important in designing an assessment protocol and synthesizing information to create a complete profile of the child. A variety of standardized and nonstandardized evaluation tools should accompany structured clinical observations and caretaker interviews. Observations of the child can yield more readily usable information than a standardized score,¹⁰⁵ enabling the therapist to view the child in natural routines, self-directed activities, and unstructured play. The interview process is essential to gather information about the child’s interactions and participation. This process paints a verbal picture of the child to help us to understand levels of functioning and participation in a variety of environments. Other crucial information obtained is how the child’s difficulties are affecting the ability to parent or teach the student.¹⁰⁵

Before choosing an evaluation tool the therapist should be aware of the intended purpose of this measure. Tools used to assess children with DCD are used for distinct purposes: identify impairments, describe severity of impairments, or explore activity or participation limitations.⁸³ The choice of evaluations may also be determined by the setting, frame of reference of the therapist, and functional concerns of the child. A therapist should be familiar with all aspects of test administration and scoring for evaluation tools and should comply with the training requirements described in the test manual. Test construction, reliability, and validity for assessing DCD should be considered. Appendix 14-A provides an overview of standardized tests available for the assessment of motor dysfunction in children with learning disabilities. Uses and limitations of the individual tests and test batteries are listed.

Identification of subtle motor difficulties is critical and challenging. These subtle motor difficulties initially can be undetected, leading to unrealistic expectations of age-level motor performance. The child’s difficulty with skilled, purposeful manipulative tasks or with finely tuned balance activities may not be readily apparent in the classroom or may be perceived as lack of effort. Children with DCD may be able to perform certain motor tasks with a level of strength, flexibility, and coordination that is qualitatively average but must use increased effort and cognitive control for sustained success.

Levels of performance in gross and fine motor testing may fall in the borderline range. Careful observations are of paramount importance, because the child’s deficits are often qualitative rather than quantitative. A child might have age-appropriate balance on testing but lack ability in weight shifting and making quick directional changes, which affects the ability to participate in extracurricular activities such as soccer or baseball. When assessing children with subtle motor deficits, it is important to realize that many evaluation tools have been developed for children with moderate to severe neurological impairments.

Children with DCD do not exhibit obvious evidence of neuropathological disease (i.e., “hard” neurological signs such as a cerebral lesion). Subtle abnormalities of the central nervous system are frequently noted by the presence of “soft” neurological signs. Deficits associated with soft neurological signs include abnormal movements and reflexes, sensory deficits, and coordination difficulties. Evaluation of soft neurological signs is typically part of an examination by a pediatric neurologist, although therapists can assess these areas in conjunction with standardized testing. Box 14-2 lists soft neurological signs frequently used to assess this population.

BOX 14-2 COMMON SOFT NEUROLOGICAL SIGNS USED IN ASSESSMENT OF CHILDREN WITH LEARNING DISABILITIES AND MOTOR DEFICITS

Minor neurological indicators

Left-right discrimination

Finger agnosia

Visual tracking

Extinction of simultaneous stimuli

Choreiform movement

Tremor

Exaggerated associated movements

Reflex asymmetries

Coordination

Finger-to-nose touching

Sequential thumb-finger touching

Diadochokinesia

Heel to shin

Slow controlled motions

Postural-motor measures

Muscle tone

Schilder’s arm extension posture

Standing with eyes closed (Romberg test)

Walking a line

Tandem walking (forward and backward)

Hopping, jumping, skipping

Ball throw and catch

Imitation of tongue movements

Pencil and paper tasks

Fine motor tasks (stringing beads, building block towers)

Sensory indicators

Graphesthesia

Stereognosis

Localization of touch input

Assessment measures of soft neurological signs vary considerably for children with learning disabilities, both in what signs are included in the assessment and how they are grouped. This list represents a compilation of possible soft neurological signs.

Researchers suggest that a high percentage of children with learning disabilities exhibit certain soft neurological signs. An early study reported that 75% of 2300 children with positive total “neurological soft sign” ratings had the symptom of poor coordination.¹⁰⁶ More recently, 169 children aged 8 to 13 years were assessed for a relation between soft neurological signs and cognitive functioning, motor skills, and behavior. Those children with a high index for soft neurological signs were found to have significantly worse scores in each domain.¹⁰⁷ The relationship between neurological soft signs and DCD is difficult to validate without more current systematic research; however, they are indicators that intervention may be needed.¹⁰⁸

In general, a composite of soft neurological signs is more predictive of dysfunction than single signs. Children without notable motor difficulties can frequently exhibit one or more soft signs; therefore identification of a single sign must be interpreted cautiously. Neurological signs involving complex processes were found to be the most predictive. The clinician needs to be familiar with typical developmental patterns, as certain soft neurological signs such as motor overflow, right-left confusion, visual tracking difficulties, and articulatory substitution are expected at younger ages and mature in quality over time.

Compiling a complete picture of motor deficits in children with learning disabilities involves assessing the following complex skills: (1) postural control and gross motor performance, (2) fine motor and visual motor performance, (3) sensory integration and sensory processing, (4) praxis and motor planning, and (5) physical fitness. Each of these interrelated functions is described in this chapter as an area of clinical assessment.

Postural control and gross motor performance

To balance effectively, we use visual information (about the body and external environment), proprioceptive information (about limb and body position), and vestibular information (about head position and movement), in order to initiate an appropriate corrective response.¹¹⁰ Balance reactions occur as a response to changes in the center of gravity that stimulate the vestibular receptors (utricles and semicircular canals). This stimulation causes muscles to activate, allowing balance to be maintained in static and dynamic activities (e.g., sitting in a chair, walking, standing on a bus). When the vestibular system works in conjunction with vision and information from the muscles (proprioception), balance is easier and more refined. Considering the impact of these sensory systems working together is important during assessment. The therapist should test the child’s balance with the child’s eyes open and closed and observe differences in ease and quality of performance. Standing with eyes closed relies more on vestibular and proprioceptive input, and difficulty may indicate that the child depends heavily on the visual system for balance. To further assess this sensory interaction, balance should also be observed on steady and unsteady surfaces (e.g., dense foam or a tilt board) with and without visual orientation. Traditional tests of balance include (1) the Romberg position—standing with feet together and eyes closed, (2) Mann position—standing with feet in tandem with eyes closed, and (3) standing on one leg with eyes open and eyes closed. The Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2)¹¹¹ and the Sensory Integration and Praxis Tests¹¹² have comprehensive balance subtests (see Appendix 14-A).

Postural control.

Postural control is dependent on muscle tone, strength, and endurance of the trunk musculature, as well as automatic postural reactions required to maintain a dynamic upright position. A child has adequate postural control when he or she can maintain upright positions, shift weight in all directions, rotate, and move smoothly between positions. These areas are often deficient in children with DCD, affecting both gross and fine motor performance.

The child may fatigue quickly and fall often during gross motor play. Other body parts may be used for additional support because of weak postural musculature—for example, placing the head on the ground when crawling up an incline or sticking out the tongue when climbing or pumping a swing. In sitting, a child with diminished postural control will fatigue quickly, either leaning on his or her hands for additional support or moving frequently in and out of the chair. These compensations affect the child’s ability to perform fine motor tasks or maintain attention for cognitive learning because so much effort is exerted on sitting up. Observing the effects of fatigue is important because both sitting and standing postures may deteriorate over the course of a day. Generally the problem stems from motor programming problems versus muscle power.

Gross motor skills.

Gross motor coordination refers to motor behaviors related to posture and locomotion, from early developmental milestones to finely tuned balance. Children with learning disabilities and DCD may attain reasonably high degrees of motor skill in specific activities. Motor accomplishments frequently remain highly specific to particular motor sequences or tasks and do not necessarily generalize to other activities, regardless of their similarities. When variation in the motor response is required, the response often becomes inaccurate and disorganized.

Although children with DCD can sit, stand, and walk with apparent ease, they may be awkward or slow in rolling, transitioning to standing, running, hopping, and climbing. Skilled tasks such as skipping may be accomplished with increased effort, decreased sequencing and endurance, and associated movements.

Evaluation of gross motor skills should include both novel motor activities and age-appropriate skills. The child, for example, can be asked to imitate a hopping sequence or maneuver around a variety of obstacles. Skills that have been accomplished can be varied slightly (e.g., hopping over a small box). Age-appropriate social participation tasks, such as tag and dodge ball, can be observed for qualitative difficulties in timing and spatial body awareness. Developmentally earlier skills also should be observed to assess the quality of performance. BOT-2 ¹¹¹ and the Peabody Developmental Motor Scales¹¹³ are examples of tools for standardized assessment of gross motor skills (see Appendix 14-A).

Fine motor and visual motor performance

Fine motor skills.

Fine motor coordination involves motor behavior such as discrete finger movements, manipulation, and eye-hand coordination. A child with DCD often demonstrates multiple fine motor concerns. Areas of difficulty typically include grasp and manipulation of small objects and dexterous hand skills, such as buttoning or putting coins into a vending machine. Assessment should include both standardized assessments and structured observations of functional performance.

A complete fine motor assessment should include observations of proximal trunk control to distal finger movements. Trunk control and shoulder stability affect the accuracy and control of reaching patterns and create a stable base from which both hands can be used to perform bilateral skills. The assessment of distal control considers wrist stability, development of hand arches, and separation of the two sides of the hand, all providing a foundation for the control of distal movement. Qualitative observations of distal fingertip control include finger motions to move objects into and out of the palm of the hand and rotate an object within the hand.

Although standardized assessments such as BOT-2 ¹¹¹ and the Peabody Developmental Motor Scales¹¹³ have fine motor sections, they do not adequately measure manipulative components described previously. Combining qualitative observations during a variety of fine motor tasks with knowledge of typical development is important. Soft neurological signs, including diadochokinesia (rapid alternation of forearm supination and pronation), sequential thumb-to-finger touching, and stereognosis (identifying objects and shapes without visual input) can provide further qualitative information.

Eye-hand coordination, visual motor integration.

Eye-hand coordination is the ability to use the eyes and hands together to guide reaching, grasping, and release of objects. This can include larger motions such as catching and throwing a ball to more refined tasks such as putting pennies in a bank or buttoning a shirt. Coordination of the eyes and the feet (eye-foot coordination) is important for skills such as ascending and descending stairs and kicking a ball. Children with DCD often exhibit difficulties in one or more of these areas. Qualitatively, they demonstrate poor coordination in the timing and sequencing of their actions. Evaluations such as BOT-2,¹¹¹ Movement Assessment Battery for Children, second edition (Movement ABC-2),¹¹⁴ and the Motor Accuracy Test of the Sensory Integration and Praxis Tests¹¹² have subtests that assess eye-hand coordination in a standardized way. Supplemental clinical observations include the assessment of ball skills, fine motor tasks such as stringing beads and building block towers, and written accuracy tasks of drawing or coloring within a boundary.

Visual motor tasks involve the ability to reproduce shapes, figures, or other visual stimuli in written form. This skill is multidimensional, involving perceiving a visual image, remembering it, and integrating it to a written response. Visual motor integration is the foundational skill needed for handwriting. In addition, handwriting involves combination of fine motor control, motor planning, and sensory feedback to be accurate and legible. Children who have difficulties with handwriting commonly produce sloppy work with incorrect letter formations or reversals, inconsistent size and height of letters, variable slant, and irregular spacing between words and letters.

Assessment of visual motor skills can be completed through standardized measures such as the Developmental Test of Visual Motor Integration (BEERY VMI, Fifth Revision),¹¹⁵ the Test of Visual Motor Skills,¹¹⁶ and the Spatial Awareness Skills Program (SASP).¹¹⁷ The production of handwritten work can be assessed by using the Evaluation Tool of Children’s Handwriting (ETCH),¹¹⁸ the Test of Handwriting Skills (THS),¹¹⁹ and Handwriting Without Tears: The Print Tool.¹²⁰ Handwriting and drawing samples provide important information regarding functional abilities in written production.

Sensory integration and sensory processing

Ayres ⁹⁹ originally defined sensory integration as “the ability to organize sensory information for use.” Information is received through the senses and organized throughout the nervous system to help us participate effectively in social, motor, and academic learning. Integration of sensory input underlies basic functions such as arousal state, attention, regulation, and postural and ocular control. Skills such as eye-hand coordination, bilateral coordination, projecting body movements in space (projected action sequences), motor planning, and skilled motor execution are end products of efficient sensory processing. More recently, it has been proposed that the term sensory processing be used for the assessment and diagnosis of sensory challenges impairing daily routines.¹²¹

The process begins with registration or recognition of incoming sensory input (“What is it?”). The incoming information is quickly scanned for relevance in a process called sensory modulation (“Is it important?”). Sensory modulation determines the appropriate action for a situation and regulates arousal. Our system needs to respond strongly and quickly if our hand moves near a hot stove, but should not respond as strongly if we are unexpectedly bumped. Discrimination of sensory input involves discerning subtle differences in sensation to learn about the qualities of objects and refine body movements within space. When we are receiving clear information from our sensory receptors we can understand and label what is happening (e.g., sour-sweet, hot-cold, soft-firm, heavy-light, up-down, fast-slow). Efficient sensory registration, modulation, and discrimination result in organized social and motor behavior.

Children with DCD often experience sensory processing difficulties. Diminished registration of sensation can result in poor body and environmental awareness, low arousal levels, and delayed postural reactions and motor coordination. These children may be sedentary or seek out strong sensation. Sensory modulation difficulties manifest primarily in emotional and behavioral responses. Behaviors often include oversensitivity, with aversive or exaggerated responses to sensation. These children struggle to remain regulated during typical daily events, and may avoid uncomfortable sensations, demonstrate behavioral disorganization, seek strong, potentially unsafe input, become aggressive, or have tantrums. They often have difficulty performing in situations involving integration of multiple inputs (e.g., cafeteria, gym class, playground, team sports). Sensitivity to movement input can also cause the child to avoid playground equipment or become nauseated during car rides. Delayed sensory discrimination typically results in poor body awareness that may underlie qualitative motor difficulties observed in children with DCD. They often exhibit poor motor coordination and planning, deficient safety awareness, and poor grading of force, as well as timing and sequencing difficulties. These children may avoid complex motor challenges, team sports, and playground activities. Discrimination difficulties can also affect the acquisition of prepositional concepts (up, down, left, right, in front of, behind, next to). The child who has difficulty discriminating information from the body typically exhibits deficits in skilled actions involving balance, timing movements in space, bilateral and eye-hand coordination, fine motor control, and handwriting.

Clinical observation of a child’s responses to a variety of sensory inputs and the ability to organize multiple inputs provides essential information regarding the integration of sensory input. Sensory modulation dysfunction is not easily identified with standardized, skill-based measures because of its physiological basis. Caregiver questionnaires, such as the Sensory Processing Measure ¹²²^,¹²³ and the Sensory Profile¹²⁴^,¹²⁵ can provide valuable information on modulation and regulation.

Gross and fine motor tasks that involve postural and ocular responses, bilateral motor coordination, planning, and sequencing reflect efficient sensory processing. Soft neurological signs, coupled with observations of play (e.g., playground, gym class, recess) can provide qualitative information on sensory discrimination and planning. The Clinical Observations of Motor and Postural Skills (COMPS) assessment tool ¹²⁶ is a set of six standardized clinical observations and soft signs that can be useful in identifying motor deficit with a postural component. The Sensory Integration and Praxis Tests,¹¹² the Miller Assessment for Preschoolers,¹²⁷ and the Toddler and Infant Motor Evaluation (TIME)¹²⁸ are used most commonly to assess various aspects of sensory integration function. Other tests, such as BOT-2¹¹¹ and the Movement ABC-2,¹¹⁴ can provide qualitative observations in addition to quantitative measures of motor skill.

Praxis and motor planning

Praxis involves the ability to plan and carry out a new or unusual action when adequate cognitive and motor skills are present. The components of praxis include ideation or generating an idea of how one might act in the environment, planning or organizing a program of action, and execution of the action sequence. Motor planning involves the same components relative to a novel motor task.

Children with praxis difficulties, or dyspraxia, may exhibit a paucity of ideas. The child may enter a room filled with toys or equipment and have limited capacity to experiment and play. Other children with dyspraxia may move from one activity to the next without generating effective plans for participating in or completing tasks. Lack of variation and adaptation in play can be another indication of planning problems. Observations of typically developing children show continuous modifications in play, with spontaneous adaptations to motor sequences, making explorations varied and increasingly successful. Children with dyspraxia often have difficulties in situations characterized by changing demands, such as unstructured group play. Transitions also may be difficult because they involve the creation or adaptation of a plan. Frustration and difficulties with peer interactions frequently are part of the composite.

Observations of motor planning deficits may include trouble figuring out new motor activities, disorganized approaches, resistance or inability to vary performance when a task is not successful, and awkward motor execution. Poor planning abilities can lead to the child being adult dependent, hesitant, or resistant to trying new activities. At times, children with dyspraxia also may exhibit poor anticipation of their actions. They can quickly engage in play with the equipment but demonstrate little regard for safety (e.g., kicking a large ball across the room where other children are playing). Movements are often performed with an excessive expenditure of energy and with inaccurate judgment of the required force, tempo, and amplitude.¹²⁹ Such children typically require more practice and repetition to master more complex, sequential movements. Frequently, children with planning problems recognize the differences between their performance and that of other children the same age, which significantly affects their self-esteem.

Manifestations of poor motor planning ability are apparent in many daily tasks. Dressing is often difficult. Children are not able to plan where or how to move their limbs to put on clothes. Problems are often demonstrated in constructive manipulatory play, such as building with toys, cutting, and pasting. Similarly, learning how to use utensils, such as a knife, fork, pencil, or scissors, is difficult. The child with dyspraxia often also has problems with handwriting.

Standardized assessments of praxis include the tests of Postural Praxis, Sequencing Praxis, Praxis on Verbal Command, Oral Praxis, Constructional Praxis, and Design Copy of the Sensory Integration and Praxis Tests.¹¹² The FirstSTEP¹³⁰ is a preschool screening tool with a section assessing motor planning abilities. Clinical observations can add valuable information regarding the child’s ability to see the potential for action, organize and sequence motor actions for success, and anticipate the outcome of an action.

Physical fitness

Physical fitness involves a person’s ability to perform physical activities that require aerobic fitness, endurance, strength, or flexibility. Factors influencing fitness include motor competency, frequency of exercise, physical health, and genetically inherited ability. Physical fitness can encompass health-related and skill-related fitness.¹³¹ Cardiorespiratory endurance, muscular strength and endurance, flexibility, and body composition are components of health-related fitness and important to monitor. Agility, speed, and power are the skill-related fitness components and are needed for the acquisition of motor skills and sports and recreational activities.¹³²

Children with DCD often have performance difficulties in games and athletic activities. They are often less active than typical peers and withdraw from physical activity. As a result, the level of physical fitness, strength, muscular endurance, flexibility, and cardiorespiratory endurance may be poorly developed. Hands and Larkin ¹³¹ found that body mass index (BMI) in children with motor difficulties was higher than in a control group of typical peers.¹³¹ The percentage of overweight and obese 10- to 12-year-olds was found to be significantly higher in a DCD group than in typically developing peers.¹³³ This increased weight may further increase their movement difficulties.

In a study of 52 children aged 5 to 8 years with DCD, Hands and Larkin ¹³¹ revealed significantly lower scores on tests for cardiorespiratory endurance, flexibility, abdominal strength, speed, and power than the age- and gender-matched controls. Another study of 261 children aged 4 to 12 years found similar disparities for children with DCD, with poor performance in fitness tests, with the exception of flexibility.¹³³ These disparities in fitness were found to increase with age between the two groups.¹³³

One task of the PT is to differentiate between poor physical fitness, resulting from low motor activity as opposed to problems of low muscle tone, joint limitations, decreased strength, and reduced endurance. The low motor activity is a neurologic sign and leads to a developmental lag or deviation in motor function. Collaboration among the physical educator, the adaptive physical educator, and the PT is critical. The President’s Challenge is a physical fitness test administered twice a year in schools across the country. Children complete five events that assess their level of physical fitness in strength, speed, endurance, and flexibility. The test was founded in 1956 by Dwight Eisenhower to encourage American children to be healthy and active, after a study indicating that American youths are less physically fit than European children.¹³⁴ Standardized assessments of gross motor functioning, such as BOT-2,¹¹¹ that assess strength, speed, and endurance can provide information related to a child’s fitness level.

Intervention for the child with learning disabilities and motor deficits or developmental coordination disorder

Creating an intervention plan

Using the information gathered throughout the assessment process, the therapist synthesizes areas of strength and weakness to develop an intervention plan. If impairments, activity limitations, and participation restrictions exist that affect the child’s successful performance, intervention may be warranted. Children with DCD, for example, might demonstrate impairments in coordination or balance that underlie activity limitations in catching or throwing a ball, which create participation restrictions in playing baseball with peers.¹³⁵ Determining the child’s functional difficulties and identifying the severity of the impairment will be important to justify service and guide the service delivery model and type of intervention. For children with DCD who have greater impairment and activity limitations, individualized treatment may be more beneficial, whereas those with less involvement may thrive with group intervention.¹³⁶

Interpreting test data, integrating findings, identifying functional limitations, and creating goals is a complex process. Initial impressions of the child’s areas of difficulty may result in the recommendation for further examination before outlining refined goals relevant to functional performance. Collecting additional assessment information may involve observations in other environments or during functional daily tasks, and/or formal testing. The end product is the creation of statements that delineate the type and quality of behavior desired as a result of remediation. In other words, the therapist must set treatment goals to be achieved through intervention.

Setting goals for the child with learning disabilities with motor deficits must be done by considering a variety of factors:

1. Referral information and age of the child

2. Medical, developmental, and sensory processing history

3. Parents’ and teachers’ perception of the child’s strengths and concerns about functional impairments

4. Educational information

a. Major difficulties experienced in school

b. How motor problems are interfering with the child’s daily participation

c. Current services being received

5. Child’s peer relationships, play and leisure activities, and self-esteem

6. Therapists’ observations and assessment of the child through informal and formal evaluation, both standardized and nonstandardized

7. Functional expectations and abilities at home and school

Goals for the child should be stated in terms of long-term and short-term objectives. Goal setting ideally involves establishing specific, measurable, attainable, realistic, and time-targeted objectives. Short-term objectives are generally composed of three parts: (1) the behavioral statement is what will be accomplished by the child; (2) the condition statement provides details regarding how the skill or behavior will be accomplished; and (3) the performance statement denotes how the skill or behavior will be measured for success. The most important consideration is ensuring that the goals and objectives chosen are relevant to the child’s functional daily performance and are meaningful to the team, including the family, working with the child. Case Study 14-3 provides an example of functional objectives.

CASE STUDY 14-3 JONATHAN

Jonathan was a 6-year-old referred for an occupational therapy evaluation by his parents and teacher because of concerns regarding motor skill development. Assessment results revealed several areas of impairment, including poor discrimination of his body position and movement in space, diminished postural control and balance reactions, motor planning deficits, delayed eye-hand coordination, qualitative fine motor deficits, and delayed visual-motor integration affecting his handwriting. Jonathan’s mother reported that he was clumsy and seemed to bump into things constantly. Of greater concern was that Jonathan seemed fearful of activities that his peers found pleasurable, such as climbing the jungle gym and coming down the slide at the neighborhood playground. Jonathan tended to play on the outskirts of groups. When he did attempt to interact he became angry because the children would not play the game by his rules. At home, Jonathan often was frustrated by tasks of daily living such as putting on his coat, snapping his pants, and tying his shoes. His mother reported that Jonathan frequently called himself “stupid” when he could not independently complete self-care skills.

When determining appropriate behavioral objectives for Jonathan, looking at the areas of functional relevance such as pleasure and safety in gross motor play, peer interactions, and independence in age-appropriate activities of daily living is critical. These areas of concern for Jonathan were consistent with those of his parents. His parents wanted him to feel more competent and less frustrated in play, at home, and at school. Jonathan’s goal was to “not be so stupid that kids won’t play with me.” The OT believed that through remediation of sensory discrimination and motor deficits Jonathan could develop improved motor competence and planning abilities. This would lead to greater success in peer interactions and improved feelings of self-confidence. Based on these common desires the following goals and objectives were made.

One of the long-term goals was Improve Jonathan’s planning and coordination abilities to increase his confidence and success in gross motor activities. Jonathan was interested in learning to ride a bicycle without training wheels, and his parents were hopeful that he could become more confident at the neighborhood playground. These behavioral objectives would measure the development of improved proficiency in discrimination of his body in space, postural control balance reactions, and motor planning. The following objectives were written:

1. Jonathan will independently climb the ladder and come down the slide without exhibiting fear, bumping into other children, or falling.

2. Jonathan will develop the ability to ride his bicycle without training wheels in straight lines and will learn to turn corners. (Note: Successfully riding the bicycle becomes the performance measure of behavior in this objective.)

To address improvement in independence for self-care:

1. Jonathan will put on his coat independently in correct orientation and successfully zip it four out of five times.

2. Jonathan will successfully tie his shoes without assistance in a timely manner.

To address greater success in peer interactions:

1. Jonathan will participate in a structured game, following the rules, for 10 minutes.

2. Jonathan will play outside with the children in the neighborhood without conflict for at least 1 hour.

Although impairment level objectives could have been written to address the same areas, they would have been of limited relevance to Jonathan and the team working with him. Balance and postural control also could be addressed by an objective stating that Jonathan would stand on one foot for 10 seconds. The functional implications of this objective would not have been clear, and Jonathan and his parents would be without an outcome measure that was measurable and meaningful to them. Thus it would have negated the effects of working as a cohesive team toward a common goal.

If the OT or PT is working as a member of a team within the school, behavioral objectives will have implications for the child’s performance in the school environment. Within the school system, statements of goals and specific objectives are included in the Individualized Educational Plan (IEP). In Jonathan’s case, specific objectives that were meaningful to the classroom situation included the ability to sit in the chair to complete written assignments for 15 minutes and increase accuracy of letter formation, size, and spacing on written assignments. Other areas related to gross and fine motor skills and peer interactions also were influential to Jonathan’s success at school. Specific objectives written pertaining to school would have functional outcome measures chosen from tasks within the school environment such as gym class, playground interactions, and classroom expectations.

Models of intervention

Improvements in motor deficits can be achieved through a variety of models of intervention, both indirect and direct. Indirect intervention involves working with key people in the child’s life to help them facilitate the child’s delineated goals. An indirect model can occur through consultation, specialized instruction, and coaching. Direct intervention involves the therapist working directly with the child on specific goal areas or skills.

Mild deficits, subtly affecting participation in activities, may be addressed through a consultative (indirect) approach. This model of service provision incorporates the use of another team member’s expertise to be responsible for the outcome of the child.⁷⁶^,¹³⁷ The therapist may suggest environmental or task adaptations to facilitate more successful participation. Consultation with parents would be appropriate for the goal of riding a bicycle without training wheels. Parents may not understand the complexity of the task and may be focused only on the end product, which can cause frustration for all involved. To facilitate confidence and success, the therapist might recommend environmental modifications such as beginning on an open stretch of grass or dirt, with no other people around to decrease the child’s anxiety. Breaking the task down into incremental steps for the parent and child (i.e., practicing getting on and off bike, balancing on still bike, gliding, braking, steering, pedaling) can allow success at each step.

Within a school setting, environmental adaptations might include changing the height or position of the desk or decreasing extraneous visual and auditory distracters. Task accommodations could include using a special grip to facilitate more refined pencil grasp or allowing more time for written work. In these instances the teacher would be responsible for carrying out the program and determining its effectiveness. Communication between the therapist and teacher encourages problem solving and changing action plans over time. Kemmis and Dunn ¹³⁸ demonstrated positive outcomes on a variety of functional classroom goals when an OT and teacher met weekly throughout the school year in what they called a “collaborative consultation approach.” Using this model they achieved 63% (134 of 213) of their outlined goals. This collaborative effort supports the shared responsibility for identifying the problem or weakness of the child, creating possible solutions, implementing the intervention as the solution, and altering the plan as necessary for increased effectiveness.⁷⁶

Another model of indirect therapy involves teaching members of the team to implement treatment strategies. Specialized instruction or coaching allows the therapist to support a child within the natural environment by working with care providers who are with the child every day. The aim is to educate key people in the child’s life to coach the child within the context of teachable moments.¹³⁹ These moments, when a child is interested and working on acquiring a new skill, occur throughout the day and in many different environments.¹⁴⁰ This allows for therapeutic consistency and repeated practice, thereby increasing the chances for skill acquisition within the context of daily routines.

With this model, the therapist observes children and adults doing familiar routines and collaborates with the adults to enhance those routines in varied environments.¹⁴¹ When implementing an intervention strategy, the therapist might teach another adult to guide specific, developmentally appropriate skill sets with the child, or problem solve to create strategies for greater success. Over time parents and other caregivers are empowered to look at a toy, an activity, or an experience and find ways to adapt it to increase successful involvement and skill development. Successful coaching can enhance parent-child relationships indirectly by helping parents to feel more comfortable and competent in their abilities to meet their child’s needs.¹⁴²

Direct intervention involves designing individualized treatment plans and carrying them out with the child individually or in a small group. This approach can focus on developing the foundations that underlie motor performance such as sensory processing, postural control, and motor planning. Specific skills, such as shoe tying or bike riding, can be practiced with the therapist as well, breaking these tasks down into component skills. Through combining approaches, adapting methods over the course of therapy, and responding to the changing needs of the child over time, progress is achieved more effectively.⁹⁷ Best practice dictates that direct therapy should always be provided in conjunction with one of the other service models to ensure generalization of skills to natural settings.⁷⁶ Without the use of other models, therapists cannot be confident that changes observed in the isolated setting are affecting the child’s overall performance.

Intervention approaches

According to the International Classification of Functioning, Disability and Health (ICF),¹⁴³ interventions should be directed toward several distinct goals:

To remediate impairment

To reduce activity limitations

To improve participation

Interventions focused on remediating impairments generally target the improvement of processing abilities (e.g., visual, proprioceptive, and vestibular) or performance components (e.g., balance and strength). The tenet is that by strengthening these foundational skills the child will develop greater success in appropriate activities and participation. This type of intervention is referred to as a “bottom-up” approach and is based on neuromaturational or hierarchical theories. Ayres’s sensory integration therapy is an example of bottom-up intervention. Missiuna, Rivard, and Bartlett ⁸³ suggest that addressing secondary, preventable impairments, such as loss of strength and endurance, may be an appropriate focus of intervention for children with DCD.

Typically, skill-based interventions are used to address activity limitations. These interventions emphasize the development of specific skills, rather than underlying components alone. This is referred to as a “top-down” approach, using cognitive strategies and problem solving. The therapist, family, and child identify specific functional activities to work on. Breaking the activity into smaller, incremental steps can facilitate the ease of learning by encouraging success. Shoe tying is a good example of a skill best taught in steps.

At times, skill-based intervention and practice occur outside the context where the child will typically perform that task. Certain skills may not be easily generalized and would be best taught in the context where the child would do the skill, such as tooth brushing. Progress is seen more rapidly when a task-related behavior that is meaningful to the child is used. Eye-hand coordination tasks, for example, become more meaningful within the context of a game of hot potato or baseball. Barnhart ⁹⁵ suggests an integrated approach to facilitating development in the child with DCD, including both bottom-up, physiological interventions, and top-down, cognitive strategies.

Recently, emphasis has shifted to models of treatment that highlight participation. Intervention focuses on increasing the child’s ability to take part in the typical activities of childhood.⁸³ These treatment methods assume that skill acquisition emerges from interaction among the child, the task, and the environment.⁹⁷ Intervention is contextually based, occurring in everyday situations and focusing on the activities and tasks inherent to that situation. Problem solving, preparatory activities, and skill training may be used together to increase successful participation. This type of approach may minimize the challenges of learning new skills for a child who cannot easily generalize learning to new situations.

The intervention methods presented in this chapter for remediation of motor deficits in the child with learning disabilities include Ayres sensory integration; neurodevelopmental treatment (NDT); motor learning approaches (e.g., Cognitive Orientation to Daily Occupational Performance [CO-OP])¹⁴⁴; sensorimotor treatment techniques; motor skill training approaches (e.g., Ecological Intervention¹⁴⁵); and physical fitness. None are mutually exclusive, and each requires a level of training and practice for competence as well as experience in normal development. Most therapists synthesize information from different intervention techniques and use an eclectic approach, pulling relevant pieces from a variety of intervention modalities to best meet the needs of each child.

Ayres sensory integration

The sensory integration theory and treatment were developed by A. Jean Ayres,⁹⁹^,¹¹² with concepts drawn from neurophysiology, neuropsychology, and development. Her purpose in theoretical development was to explain the observed relationship between difficulties organizing sensory input and deficits in academic and neuromotor “learning” observed in some children with learning disabilities and motor deficits.¹⁴⁶ The theory proposes that “learning is dependent on the ability of normal individuals to take in sensory information derived from the environment and from movement of their bodies, to process and integrate these sensory inputs within the central nervous system, and to use this sensory information to plan and organize behavior.”¹⁴⁶ Ayres¹¹² used “learning” in a broad sense to include the development of concepts, adaptive motor responses, and behavioral change.

The goal of sensory integration intervention is to elicit responses that result in better organization of sensory input for enhanced participation and generalization of functional skills. Sensory integration treatment is based on the belief that active involvement in individually designed, meaningful activities that are rich in sensory input will enhance the nervous system’s organization and integration of sensation.¹⁴⁷ Active exploration and variation in the context of play results in adaptive responses,¹⁴⁸ which positively affect the child’s ability to participate in daily life activities. During intervention, sensory input is provided in a planned and organized manner while eliciting progressively harder adaptive behavioral and motor responses. The therapist strives to find activities that are motivating and tap the child’s inner drive to encourage adaptation. “Evincing an adaptive behavior promotes sensory integration, and, in turn, the ability to produce an adaptive behavior reflects sensory integration.”⁹⁹ Effective intervention requires melding the science of a neurophysiological theory with the art of “playing” with the child.

A sensory integration treatment session for a child with postural difficulties might involve having the child riding a swing pretending to be a fisherman while keeping a lookout for whales that might bump his boat. This “pretend play” scenario taps the child’s motivation and inner drive to be productive (fishing), while challenging him with a potential “out of my control” situation (whales). The therapist will adapt this activity in a variety of ways to maintain an appropriate level of challenge and adaptation (adaptive response). The type and amount of sensory input, postural demands, bilateral control, timing, and planning requirements are all considered and can be adapted to an easier or harder level to maintain adaptation and learning. Sensory input can be controlled through the speed and direction the boat moves and the amount of work the child must do with his arms to propel the boat and catch fish. Additional sensory input can be provided through “rocky seas” and “whales crashing the side of the boat.” The boat can facilitate more or less postural adaptation by the amount of support it provides and the speed of its movement. The child can pull a rope to propel the swing, or the therapist can provide the movement to decrease the bilateral coordination and postural demands. A more demanding bilateral response could include pulling a rope and catching a fish simultaneously. Unexpected movements of the boat, fish, and whales will require greater timing and planning for success.

For this intervention technique to be appropriate, the motor and planning difficulties observed in a child with learning disabilities need to be a result of deficits in processing sensory information. Each child’s intervention plan should be individualized based on the results of a comprehensive evaluation and responses to sensory input within therapy. Contributions of sensory registration, modulation, and discrimination should be considered for their impact on functional performance including social, emotional, and motor development. Children with sensory processing difficulties will exhibit problems that limit their occupational performance in a variety of environments.¹⁴⁹

Vestibular, proprioceptive, and tactile sensory inputs used in therapy are powerful and must be applied with caution. The autonomic and behavioral responses of the child must be monitored carefully. The therapist should be knowledgeable about sensory integration theory and intervention before using these procedures. Monitoring behavioral responses after the therapy session also is suggested through parent or teacher consultation. Intervention precautions are elaborated by Ayres,⁹⁹ Koomar and Bundy,¹⁵⁰ and Bundy.¹⁵¹

Research on the effects of sensory integration procedures.

Sensory integration is an evolving theory, based on developments in the fields of neuroscience, research, and clinical practice.¹⁵² The current neuroscience literature supports the basic tenets of sensory integration including neuroplasticity, and positive changes in behavior and learning as a result of enriched environmental conditions, dynamic participation in meaningful activities, and developmentally appropriate sensory motor experiences.¹⁴⁷ Within the field of occupational therapy, sensory integration is the most extensively researched intervention procedure, with over 80 research studies that measure some aspect of treatment effectiveness.¹⁵³ Clinically, sensory integration principles are estimated to be used by approximately 90% of American OTs working in the school system for children with learning disabilities and motor deficits.¹⁵⁴ Despite over 35 years of theoretical development, research, and intervention practice, the value and effectiveness of this therapeutic modality continues to be questioned and critiqued.^155–158 The complexity of sensory integration theory, the individualized approaches that treatment warrants, and the difficulty finding sensitive outcome measures create many challenges in designing appropriate and valid research studies.

Clinicians using sensory integration procedures attest to the effectiveness of this treatment approach in making important functional changes. Testimonials from parents of children who have received occupational therapy with sensory integration procedures are frequently heard. In Cohn’s research, parents identified two important outcome measures for intervention.¹⁵⁹ The first included change in the child, such as improved self-regulation, perceived competence, and social participation. The second was related to parents developing the ability to understand their child’s behavior in a new way and having their experiences validated to better support and advocate for the child.

Accurate analysis of the efficacy of sensory integration is complicated by a wide variety of methodological design flaws in the available research. The majority of the studies include heterogeneous samples, small sample sizes, and inconsistencies in the frequency, length, and duration of treatment. Schaaf and Miller ¹⁵³ note that a major challenge in interpreting the existing research is related to the outcome measures used. Researchers have not consistently used a theoretical base to explain how treatment techniques influence the outcomes chosen.¹⁵³ In addition, the dependent variables measured were often not related to the expected outcomes of treatment, were too many in number, or were poor measures of change over time.¹⁵³^,¹⁵⁶ Many studies include outcome measures that are not sensitive to small increments of change or meaningful to parents as treatment priorities.¹⁵⁹

Perhaps the most challenging aspect of developing strong research studies is the variability of sensory integration intervention. Treatment is individualized and adapted frequently in response to the child’s changing needs and successes.¹⁶⁰ Many of the studies that claim to be using sensory integration therapy do not adhere to the core theoretical principles, or they violate them.¹⁶¹ Developing standardized and replicable treatment is a major challenge for future research studies. Researchers and clinicians have focused extensively on improving the quality of efficacy research, resulting in the development of improved functional outcome measures (goal attainment scaling)¹⁶² and treatment fidelity (fidelity measure).¹⁶¹ Significant progress has also been made in defining homogeneous subgroups for analysis, describing replicable treatments, and choosing valid outcome measures.¹⁵³

Schaaf and Miller ¹⁵³ note that diverse findings are not surprising given the current level of research. The knowledge base in sensory integration research is still in its infancy, with the need for substantial work to generate more rigorous empirical data to support the efficacy of this intervention approach.¹⁵³ Increased emphasis on high-quality, randomized controlled studies is essential.¹⁶³

Approximately half of the research studies conducted to date show some positive effects, with sensory integration treatment being more effective than or equally as effective as other approaches used.¹⁵³ In a recent systematic review of 27 research studies, May-Benson and Koomar¹⁶⁴ concluded that the synthesis of evidence indicates that sensory integration may result in a variety of positive outcomes. Specific areas identified included sensory-motor skills, motor planning, social skills, attention, behavioral regulation, and reading and reading-related activities, as well as functional outcomes as measured by individually designed goal attainment scales (e.g., improved sleep patterns, increased food repertoire, pumping a swing, and manipulating fasteners). Positive gains in motor performance were found in 10 of 14 studies reviewed, with the implication that the gains were maintained after the cessation of treatment. Arbesman and Lieberman¹⁴⁹ identified that the positive development of motor skills as a result of sensory integration intervention was most consistently noted in their review of 198 articles. Other recent, well designed studies have demonstrated positive effects on behavioral outcomes including significant gains in attention, cognitive and social skills,¹⁶³ and socialization¹⁶⁵ and increased engagement, with decreased aggression.¹⁶⁶ May-Benson and Koomar¹⁶⁴ suggest that given the current level of positive results, OTs can begin to use this information to support the use of sensory integration treatment, particularly for sensory motor outcomes and client-centered functional goals.

Neurodevelopmental treatment

NDT is a treatment technique formulated by Karel and Berta Bobath ¹⁶⁷^,¹⁶⁸ to enhance the development of gross motor skills, balance, quality of movement, hand skills, and daily tasks such as mobility and self-care for individuals with movement disorders.¹⁶⁹^,¹⁷⁰ These techniques were originally designed for use with children with cerebral palsy in whom the underlying problem was a lesion in the central nervous system that produced abnormal muscle tone and deficits in coordination of posture and movement, affecting functional performance.¹⁶⁸ The original framework was based on hierarchical levels of reflex integration in the nervous system and the normal developmental sequence. Abnormal postural responses were lower-level hierarchical reactions that did not integrate in a typical time frame (e.g., ATNR, STNR), thereby inhibiting the development of mature postural mechanisms and voluntary movements. The NDT approach emphasized specific ways to inhibit abnormal reactions and facilitate more normal muscle tone and movement.¹⁷¹^,¹⁷² The assumption was that encouraging more normalized automatic movement patterns would lead to functional carryover.¹⁷²

The original hierarchical “impairment-based” model of reflex integration has been replaced with a more dynamic “interactive systems” model that emphasizes both internal and external factors of motor control. Currently, NDT therapists view the execution of movement as a complex interaction of the neural and body systems, organized by the specific task requirements and constrained by physical laws of the environment.¹⁷⁰ The nervous system is viewed as dynamic and adaptable, capable of initiating, anticipating, and controlling movements with ongoing sensory feed-forward information and feedback.¹⁷⁰^,¹⁷³ Many body factors are recognized as contributing to dysfunctional movement patterns, including abnormal muscle tone, primitive reflex patterns, delayed development of righting and equilibrium reactions, specific muscle weakness, body biomechanics, cardiovascular or respiratory weakness, lack of fitness, and sensory, cognitive, or perceptual impairments.¹⁷⁰^,¹⁷³^,¹⁷⁴ As NDT’s theoretical and clinical development progressed, there was acknowledgement that intervention had not automatically carried over into functional performance as had been anticipated. As a result, treatment strategies began to shift, with preparation for specific functional tasks done in settings where children typically participate.¹⁷⁵ The focus on normalizing muscle tone and altering movement patterns as a foundation for performance was replaced with emphasis on activity-related impairments and client-directed functional outcomes.¹⁷⁰^,¹⁷²^,¹⁷³ Ecological, family-centered intervention was identified as essential to target key environments, activities, and functional outcomes.¹⁷⁰ This dynamic treatment approach now emphasizes active involvement in meaningful tasks to enhance independent participation in various environments. The goal of NDT intervention is for the child to use more efficient movement strategies to complete life skills with greater success. Over the life span these strategies will minimize secondary impairments that can create additional functional limitations or disability.¹⁷⁰^,¹⁷⁴

NDT uses physical handling techniques directed toward developing the components of movement necessary for functional motor performance. Movement components of postural alignment and stability, mobility skills, weight bearing, weight shifting, and balance are all foundations for smoothly executed movements in space.¹⁶⁹ Assessment and analysis of posture and movement components are ongoing, using a problem-solving approach that identifies and builds on the child’s strengths and limitations.¹⁷⁰ Therapists employ a combination of handling techniques and encouragement of active movements targeted toward the specific functional skills on which the child is working.⁹⁸ Feedback involves both tactile-proprioceptive (“hands-on”) and verbal cues, which are graded back or changed according to the needs and emerging skills of the individual child.¹⁷² The therapist’s hands guide the reactions, with the child actively participating in problem solving and adapting performance. Practice of more effective postural reactions and reduction of abnormal movement patterns are embedded into meaningful activities. A skilled therapist balances the quality of movement patterns with the importance of active involvement in learning new motor tasks.¹⁷³ At times, participation and independent task completion are more important than qualitatively normal movement patterns.

Although NDT was developed for children with central nervous system insults resulting in deficient postural and movement control for daily skills, it lends its use to children with more minimal motor involvement. Of particular relevance to the child with learning disabilities and DCD is facilitation of improved righting and equilibrium responses, automatic postural adjustments, and balance reactions. Handling techniques can help develop improved qualitative control, as well as encouraging active problem solving and task adaptation by the child.

Research on the effects of neurodevelopmental treatment.

NDT is an evolving theoretical and treatment approach, based on principles derived from research in neural plasticity, motor development, motor control, and motor learning.¹⁷⁰ It is the most commonly used treatment framework for children with cerebral palsy.¹⁷⁶ Despite this, relatively few studies are available on the efficacy of NDT to date.¹⁷² Those that are available have not definitively shown NDT to be effective as a treatment modality or more valuable than other therapies.¹⁷⁵^,¹⁷⁷ One of the major problems confounding interpretation of the current state of research has been the significant change in theoretical development and clinical application over time. The revised practice model of NDT is better reflected in the current research, which shows more promise.¹⁷⁰^,¹⁷⁸ It has been suggested by Bain¹⁷² that studies conducted before 2000, when NDT was defined with outdated operational definitions, should not be considered as evidence that current practice is ineffective.

Methodological concerns in many of the available studies make interpretation of efficacy more challenging. In a review of older treatment studies, Royeen and DeGangi ¹⁶⁹ noted significant methodological problems that were attributable to the lack of conclusive evidence regarding NDT. These included poorly defined objective outcome measures, overreliance on subjective clinical observations, and small sample sizes. In addition, sample populations varied greatly, including adults and children with cerebral palsy and Down syndrome as well as high-risk infants. More recently Sharkey and colleagues¹⁷⁸ highlighted difficulties in developing well designed treatment studies, including the heterogeneity of children with cerebral palsy, both in functional limitations and goals, small sample sizes, and ineffectiveness of standardized outcome measures to assess qualitative and functional changes. Butler and Darrah¹⁷⁵ cautioned interpretation of efficacy from the 21 studies they reviewed owing to unclear population definitions, unclear treatment protocols and goals, and lack of clarity regarding therapist skill levels.

Several current research studies have demonstrated positive changes in gross motor performance as a result of intensive NDT intervention.¹⁷⁶^,¹⁷⁹^,¹⁸⁰ Arndt and colleagues¹⁷⁹ used an operational definition of NDT based on trunk coactivation for treating infants with posture and movement difficulties. After 10 hours of treatment over 15 days, the infants who received the NDT protocol significantly improved in gross motor function compared with infants in the control play group. These skills were maintained at a 3-week follow-up evaluation. Bar-Haim and colleagues¹⁷⁶ used a randomized controlled trial for 24 children with cerebral palsy, with 40 hours of treatment over a period of 4 weeks. They compared intensive NDT treatment with the use of the Adeli suit (AST), which stabilizes the trunk and extremities of the wearer to help normalize motor actions.Although there was no superiority noted between these two intensive treatment modalities, both groups made significant gains in gross motor function that were sustained after nine months. Tsorlakis and colleagues¹⁸⁰ further assessed the variable of intensity of services in their 16-week treatment study. The efficacy of NDT for children with spastic cerebral palsy was supported by this study, as both groups of children who received NDT intervention demonstrated statistically significant gains in gross motor function. Increased intensity of services was also supported, as motor gains were statistically greater for the group that received intervention five times a week compared with two times a week.

Brown and Burns ¹⁷⁷ completed the only systematic review that was identified as high quality by colleagues.¹⁸¹ They selected 17 studies to include on the basis of use of NDT as the treatment modality, reported clinical outcomes, and random group assignment. Their analysis did not provide definitive evidence that NDT is beneficial for children with neurological dysfunction. The authors suggest that available research did not reveal either efficacy or inefficacy of NDT as a treatment approach. Butler and Darrah¹⁷⁵ suggest that absence of evidence on the effectiveness of NDT should not be construed as proof that the treatment is not effective, but certainly reflects areas in which more meaningful research is needed. Sharkey and colleagues¹⁷⁸ suggest that recognition of these limitations will encourage practitioners to implement “second-generation” research that is characterized by well designed studies that systematically evaluate operationally defined intervention techniques and determine what works for specific ages and diagnoses of children.

Motor learning theories

Motor learning refers to the process of acquiring, expanding, and improving skilled motor actions. The basic treatment premise of motor learning theories is that improvement in movement skills is elicited through appropriate practice and timely feedback. Motor learning has taken place when a permanent change in the child’s ability to respond to a movement problem or achieve a movement goal has occurred, regardless of the environment.¹⁸² Therefore therapists measure learning through tests that measure retention and transfer of skills.¹⁸³

The closed-loop theory of Adams ¹⁸⁴ is recognized as the first comprehensive explanation for motor learning. Adams believed that the central nervous system, based on sensory feedback, controls the execution of movement. He proposed that once a movement has occurred, errors are detected and compared with existing “memory traces.” With practice, these memory traces become stronger and the accuracy of the movement increases, thus emphasizing learning through feedback.

In 1975 Schmidt contributed the idea of “open loop” motor learning, which emphasized the ability to produce rapid action sequences in the absence of sensory feedback (e.g., hitting a baseball). He proposed that new movements were created from previously stored motor programs (schemas) of similar movements, as opposed to feedback from individual motor actions.¹⁸⁵ Schemas comprise general rules for a specific group of actions that can be applied to a variety of situations.¹⁸⁶ When a motor action occurs, the initial movement conditions, parameters used, outcomes, and sensory consequences of the action are stored in memory. With each goal-directed movement, specific parameters are used (e.g., force needed to pour juice into a glass), and consequences occur (e.g., spillage or not). Repeated actions using different parameters and creating different outcomes create data sets that help refine the motor program, reducing errors and improving anticipation or feed-forward information.¹⁸⁶ Schmidt’s¹⁸⁵ schema theory contributed to current theories of motor learning principles regarding practice schedules and feedback about outcome of movements, known as knowledge of results.

Based on the knowledge of motor skill development in children with DCD, four key variables are important to consider in targeted intervention. They include stage of the learner, type of task, scheduling of practice, and type of feedback.

Three stages of the learner have been proposed ¹⁸⁷^,¹⁸⁸: the cognitive stage, the associative stage, and the autonomous stage. As a child learns and develops new motor actions, he or she progresses through the various stages at different rates, depending on the complexity of the skill. The cognitive stage is the initial phase of learning in which there is large variability as the child gets the general idea of the movement.¹³⁵ Awkward body postures are observed, errors are often made, and awareness of what needs to be improved or changed does not exist. (Consider when a young child attempts to throw a ball; the throw is a gross movement, the projection of the ball varies, and the movement appears uncoordinated.) As practice continues, the degree of accuracy increases, which is characteristic of the associative stage. Fewer errors are made and error information is used to correct the movement patterns. (As the child continues to throw the ball, the ball may get closer to the target with improved coordination observed.) During the autonomous stage, the skill is performed fluently and automatically, without as much effort or thought. Improvements in accuracy continue and errors are detected, with corrections made automatically. (The child can now throw a ball at a target and hit the target with coordinated, accurate movements, such as pitching; however, if a child were introduced to throwing a curve ball, the stages would start over.)

The type of task is a mechanism to classify motor skills in a dimensional fashion. Task components contribute to intervention decisions. The types of tasks are gross motor or fine motor; simple or complex; discrete, serial, or continuous; and environment changing or stationary. Gross and fine motor tasks are classified according to the type of muscle groups required.¹⁸⁹ Gross motor skills use large muscles and tend to be fundamental skills (e.g., walking and running). Fine motor skills tend to require greater control of small muscles and usually have to be taught (e.g., handwriting, cutting). Task complexity refers to the level of difficulty and amount of feedback required. Simple tasks, such as reaching, require a decision followed by a response. A complex task, such as cutting out a picture, requires continual monitoring and feedback until completion. Tasks can require simple single actions or the coordination of sequential motions for completion. A single discrete movement has a clear beginning and ending, such as activating a button. Serial movements require a series of distinct movements combined to achieve the outcome, such as writing a sentence. Continuous movements, such as running, contain movements that are repetitive. Tasks that are discrete or serial can be practiced in parts, but continuous tasks usually need to be practiced as a continuous segment.

Environmental variations can greatly increase the complexity of the task, requiring higher levels of feed-forward information and feedback. In an unstable or changing environment, the child has to learn the movement and monitor the environment to adapt to changes—for example, running on an uneven surface. The more predictable and stable the task and environments are, the easier it is to learn and replicate motor skills. Tooth brushing is an example of a task that generally occurs in a stationary environment. Home and classrooms can be stable, in that many elements within these settings are fixed and do not change. The size and shape of chairs, location of toys on the floor, and movements of other children are considered “variable features” within these stable environments. These variable features require a greater amount of motor control because the child must adjust movements and actions to the changing demands. Therapists generally practice in stable environments and therefore must ensure that the children are able to function under varied circumstances encountered in daily life situations.

Practice is believed to increase learning of a skill or movement. Variations in practice can occur in the order tasks are performed, in the environment where the tasks are practiced, and by changing aspects of the task. Practice schedules can be developed based on the practice techniques (blocked or random), or how task learning is approached (component or whole task). Blocked practice means the task is repeatedly rehearsed, sometimes focusing on one aspect of a technique or a specific motor sequence (e.g., hitting a golf ball off a tee with the same club). Repetitive, blocked practice often leads to improved immediate performance, particularly in situations that are stable. Random practice involves performing a number of different tasks in varied order or employing several different aspects of technique (e.g., hitting golf balls from a tee, sand trap, and rough with the appropriate club). Random practice encourages learners to compare and contrast strategies used in performing the task, which positively influences performance in changeable environments.

If a task is discrete or contains multiple parts, breaking it down into components for blocked practice may be beneficial. For success in changeable situations in which the task component is integrated into skilled action, whole-task practice is essential—for example, practicing shooting basketballs, then practicing while moving or running toward the basket. When generalization is the goal, practice sessions can progress from stable (shooting from specific positions on the court) to a changeable environment (such as shooting basketballs with a person trying to block the shot). Opportunity and variety in practice appear to improve motor learning, particularly when skills are practiced in a random manner. Practice should therefore be varied and occur in multiple environments (e.g., home and school) to maximize motor learning.

Different types of feedback also affect the process of learning. Intrinsic feedback is received from any of the child’s internal sensory systems and is usually not perceived consciously unless external direction draws attention to it (e.g., when a child performs a task with his or her tongue sticking out). Extrinsic feedback is received from an outside source observing the results of an action and can be provided in the form of knowledge of performance (KP) or knowledge of results (KR). KP focuses on movements used to achieve the goal, whereas KR focuses on the outcome.

Therapists tend to provide excessive feedback, especially when task performance is below what is expected. Low frequency and fading feedback, progressively decreasing the rate at which feedback is provided, appear to be most effective in facilitating learning.¹²⁹ One proposed reason is that with less feedback the individual can more readily engage in the processes that enable learning versus focusing on external cues. During intervention, feedback should not be provided for every movement or task execution. It is more beneficial to offer children the opportunity to self-evaluate and correct their own performance. The therapist can provide feedback as necessary to encourage successful task completion and reduce frustration. Verbal feedback can be general—”Did that work?”—or specific—”Do you need to throw it harder or softer to reach the target?”

Children with DCD often lack the skills required to analyze task demands, interpret environmental cues, use knowledge of performance to alter movements, or adapt to situational demands.¹⁹⁰ They therefore do not interpret and use sensory or performance feedback as well as children who are developing typically.¹⁸³ Motor observations of the child with DCD often reveal clumsiness, difficulty judging force, timing, and amplitude of motions, and deficits in anticipating the results of a motor action. Reactions, movements, and response times are typically slower.¹⁹¹ With this in mind, the type of task and the method of teaching should be considered when recommending participation in sports and leisure activities.¹³⁵ Children with DCD can become successful in repetitive sports, such as swimming, skating, skiing, and bicycling. Ball-related sports, however, such as hockey, baseball, tennis, football, and basketball, tend to be more difficult and frustrating owing to the high level of unpredictability and frequent changes in the direction, force, speed, and distance of the movement.¹³⁵

When using the motor learning model of practice, the therapist should incorporate a variety of teaching techniques including verbal instructions, positioning, and handling, as well as observational learning (demonstrations).¹⁸³ The task and environment should be structured with extrinsic and intrinsic feedback provided, using a practice schedule that is optimal for the type of task.¹⁹² Children with DCD benefit from experiential and guided learning when practice is performed so that each repetition of the action becomes a new problem-solving experience. To test whether motor learning has occurred, the therapist must create opportunities for demonstration of retention (repeating what was learned in a previous session), transfer (perform a different but closely related task), and generalization (perform a learned task in a new environment).

One method of intervention based on the principles of motor learning is the CO-OP, a frame of reference developed as a treatment approach specifically for children with DCD.¹⁴⁴ In this cognitive-based approach, the therapist focuses on the movement goal and facilitates the child’s identification of the important aspects of the task, examines the child’s performance during the task, identifies where the child is having the most difficulty, and problem solves alternative solutions.¹⁹² Rather than using verbal instructions, this approach uses guided questions to help the child discover the problems, generate solutions, and evaluate his or her attempts in a supportive environment. Furthermore, the therapist solicits verbal strategies from the child that can help guide the motor behavior, such as typical verbal cues that the therapist tends to provide during intervention.

To benefit from the CO-OP approach, the child must have sufficient cognitive and language ability to rate the level of his or her performance and satisfaction of self-identified goals using the Canadian Occupational Performance Measure (COPM).¹⁹³ The basic objectives of this approach include skill acquisition, cognitive strategy development, and generalization or transfer of skills into daily performance. CO-OP is delivered over 12 one-on-one sessions, each lasting approximately 1 hour. The therapy process is divided into five phases: preparation, assessment, introduction, acquisition, and consolidation. Children are taught to talk themselves through performance issues using an approach of Goal-Plan-Do-Check. Domain-specific strategies are used to enhance performance, with the purpose of helping the child to see how he or she can set goals, plan actions, talk through doing, and check outcomes. Using this frame of reference, therapists help the child acquire occupational performance skills using a metacognitive problem-solving process.¹⁴⁴

Research on the CO-OP model of motor learning.

Current beliefs regarding the nature of motor learning for children with DCD suggest that assessment of participation, versus impairments, should be used to determine change over time.¹⁸³ By increasing the child’s ability to participate in childhood activities, secondary deficits such as loss of strength and endurance might be prevented. Relatively new intervention strategies that employ contemporary motor learning principles emphasize the role of cognitive processes (top down) in development of specific skills. The CO-OP model uses this approach to help children achieve their functional goals.¹⁴⁴

Research on the effectiveness of this approach to improve motor skills and functional performance is limited but shows promise. Polatajko and Cantin ¹⁹⁴ reviewed three articles describing four studies and concluded that there was convergent evidence for the effectiveness of the CO-OP approach for children with DCD.

An exploratory study completed in 1994 by Wilcox as part of his graduate work was discussed by Polatajko and colleagues.¹⁹⁵ This initial single case study included 10 children aged 7 to 12 years who were referred to occupational therapy for motor problems. Using a global problem-solving approach to intervention, this study sought to identify whether children with DCD could use these strategies to acquire skills of their choice, and, once learned, whether the skills were maintained and performance in other areas enhanced. Children selected skills that were challenging and meaningful for them, such as shuffling playing cards, applying nail polish, making a bed, and writing legibly. Each of the 10 children made gains in the chosen activity, with 29 of the 30 targeted skills showing improvement.

A pilot study compared the CO-OP model to a traditional treatment approach with a group of 20 children aged 7 to 12 years. Findings indicated that the CO-OP model of intervention produced larger gains on client-selected goals. Improvements in self-ratings of performance and satisfaction were greater than in the comparative group. Although informal, the follow-up data suggested that children maintained their acquired skills and applied strategies to other motor goals.

Limitations in making conclusions regarding the effectiveness of this treatment are mandated by the small number of research studies, primarily carried out by the same research group. Mandich and colleagues ⁹⁷ suggest that larger studies with control groups are needed. Suggestions for future research include identification of the salient features of this treatment approach, as well as determining the generalization and skill transfer to other settings.

Sensorimotor intervention

Sensorimotor activities provide the foundation for the development of play in children.¹⁹⁶ The first level of play (i.e., sensorimotor) is pleasurable, intrinsically motivated activity that involves the exploration of sensation and movement.¹⁹⁶ As children react with adaptive motor responses to the array of sensations from their bodies and the environment, central nervous system organization occurs. The assumption that the organization of sensory and motor experiences is essential to effective motor performance is the premise of sensorimotor intervention.¹⁹⁷ Treatment encourages the child to actively engage in a variety of sensory-rich, motor-based activities, to enhance functional motor performance.¹⁹⁵ Evolution of sensorimotor intervention has not revolved around a single, unified theory but has incorporated a variety of theoretical foundations.¹⁹⁸

The goals of sensorimotor intervention are outcome based, with emphasis on the development of age-appropriate perceptual-motor and gross motor skills. The therapist chooses activities that meet the child’s developmental levels, promote sensory and motor foundations, and encourage practice of appropriate motor skills. For the child having difficulty keeping up with the skilled activities in gym class such as rope jumping, components of these activities will be encouraged, with emphasis on sequencing and timing. The therapist may use a heavier jump rope or wrist and ankle weights to provide more sensory information for improved task performance.

In sensorimotor intervention, tasks are chosen for their innate sensory and motor components. The child is directed to activities that encourage the use of the body in space to complete a structured motor sequence. Activities incorporate sensory components such as movement (vestibular), touch (tactile), and heavy work for the muscles and joints (proprioception). Play interactions are considered important to encourage sensorimotor integration within the context of meaningful interactions with persons and objects.¹⁹⁶ Children may propel themselves prone on a scooter board through an “obstacle maze” while looking for matching shapes, for example. This activity provides tactile, proprioceptive, and vestibular sensory input and encourages the development of postural strength and endurance while addressing perceptual skill development.

Research on sensorimotor intervention.

Sensori-motor intervention is a widely accepted modality, used by 92% of school-based therapists as a foundation for improving handwriting.¹⁹⁹ The activities used and goals addressed in treatment are extremely varied, as all functional motor skills involve some level of sensory and motor organization. Activities can range from horseback riding to using a vibrating pen when learning how to write letters. Owing to the enormous variation in intervention strategies and outcome measures, operationalizing treatment to make comparisons between research studies can be difficult. In a recent systematic review Polatajko and Cantin¹⁹⁴ found five studies that met their criteria for using sensorimotor intervention. In those five studies both the techniques used (e.g., therapeutic riding, movement therapy, educational kinesiology) and the populations addressed (autism, sensory modulation disorder, DCD) varied greatly. This review suggested that evidence for the effectiveness of sensorimotor intervention was “inconclusive,” with the heterogeneity of diagnoses and functional problems limiting the ability to interpret efficacy.¹⁹⁴

Overall, relatively few studies have investigated the efficacy of sensorimotor integration. In an early comparison study, DeGangi and colleagues ²⁰⁰ found that children provided with structured sensorimotor therapy made greater gains in sensory integrative foundations, gross motor skills, and performance areas such as self-care than children who engaged in child-centered activity. More recently, Chia and Chua²⁰¹ used sensorimotor intervention in a random controlled study of 14 children with learning disabilities and DCD. Intervention consisted of providing sensory stimuli and facilitating a normal motor response while remediating impairments in posture and muscle weakness. Positive results in neuromotor functioning were noted. In a second study, Inder and Sullivan²⁰² used educational kinesiology techniques in four single-subject design experiments. Positive gains were documented in some aspects of sensory organization and in an overall decrease in the number of falls children had.

Four studies have explored the effects of sensorimotor remediation on handwriting. Those programs that used sensorimotor interventions over only a short period of time did not yield positive results. Sudsawad and colleagues ²⁰³ compared the effects of kinesthetic-based intervention with handwriting practice with 45 first graders over a 4-week period. They found neither group to make significant improvements in handwriting, and suggest that there is no support that kinesthetic training improves handwriting legibility for this age. In 2006, Denton and colleagues²⁰⁴ compared sensorimotor intervention with therapeutic practice in 38 school-age children with handwriting difficulties over 5 weeks. These authors noted moderate improvements in handwriting with therapeutic practice and a decline in ability in the sensorimotor group. They suggest that although sensorimotor foundations did improve with sensorimotor intervention, there is no indication that these foundations affect the development of handwriting. Their findings suggest that structured therapeutic practice using motor learning principles has a much stronger impact on the development of handwriting.

Two studies that investigated the combined effects of sensorimotor intervention and higher-level teaching strategies did demonstrate a positive impact on handwriting.²⁰⁵^,²⁰⁶ Peterson and Nelson²⁰⁵ found that low socioeconomic first graders who received 20 sessions of occupational therapy combining sensorimotor, biomechanical, and teaching-learning strategies made significant gains over those receiving academic instruction alone. Weintraub and colleagues²⁰⁶ compared a control group with two treatment conditions (task-oriented approach versus combination of sensorimotor and task orientation). Immediately after treatment, and at a 4-month follow-up, significant gains in handwriting were observed in both treatment groups compared with the control group. The authors support the use of “higher-level” teaching strategies to improve the skill of handwriting.

Motor skill training

Motor skill training involves learning skills and subskills functionally relevant to the child’s daily performance. Tasks are taught in a sequential manner by developmental ages or by steps from simple to complex. Skill training can occur for a wide variety of gross, fine, and visual motor tasks, as well as activities of daily living. An assortment of theoretical models and techniques may be used based on the child’s impairment and activity and participation deficits.

Motor skill training can involve both indirect and direct facilitation of specific motor tasks. Activities that include balance, locomotion, body awareness, and hand-eye coordination can improve functional skills such as being able to sit at a desk within the classroom and complete written work, as well as success in recess games such as basketball. Specific skills such as dribbling and foul shooting can also be specifically taught and practiced. The goal is to provide a great variety of motor activities at the child’s developmental motor level to promote motor generalizations for more successful participation.

An example of this approach is Sugden and Henderson’s ¹⁴⁵ “ecological intervention,” which is a method of skill training for children with DCD. In this model the therapist, called a movement coach, provides instruction to many individuals who interact with the child on how to develop specific targeted skills. All caregivers are actively involved in goal development and achievement. By having a variety of individuals work together across daily life environments, children more quickly become skilled.¹⁴⁵ This approach also develops the caregivers’ ability to understand the demands of specific tasks and to help facilitate the child’s performance in all settings.

Physical fitness training

As previously reviewed, children with DCD are at great risk of low levels of physical fitness. The benefits of fitness and physical activity in minimizing disease and maximizing overall wellness are well documented. Deleterious effects resulting from DCD or factors associated with it include but are not limited to fatigue, hypoactivity, poor muscle strength and endurance, decreased flexibility, poor speed and agility, and diminished power.

Specific muscular training may be needed to undo the effects of reduced activity.²⁰⁷ Poor muscle strength, especially in the abdominal area, can lead to musculoskeletal issues such as back pain because posture and pelvic alignment require adequate muscle strength. Children with DCD often require specific instruction to perform muscle strengthening activities (e.g., sit-ups, push-ups) with appropriate form. Decreased flexibility and muscle tightness in the lower extremities can contribute to difficulties in running, jumping, and hopping. Flexibility can be encouraged with a regimen of stretches specific to the areas of tightness. Gentle and regular stretching can be incorporated into warmups during sessions or physical activities.

Fitness can improve and be maintained when children participate in regular, preferably daily, physical activity. These activities often require more structure and direction for children with movement difficulties. As therapists, our overall goal should be to educate children about the value and enjoyment of regular activity.²⁰⁷ Hands and Larkin²⁰⁷ suggest the following plan to ensure children with DCD learn or rediscover the joy of movement:

Educate children to understand and monitor their bodies’ responses to exercising (e.g., heart rate increases when they run).