INTRODUCTION

After most surgical and nonoperative primary and secondary treatment approaches have been exhausted, the majority of patients with occupational musculoskeletal disorders have returned to work and decreased their health utilization. Depending on the US state or federal workers’ compensation venue and musculoskeletal area, an average of about 10% of patients persist with workers’ compensation disability 3–4 months postinjury. The range is about 5–25%, with a smaller (but growing) group of patients persisting in ‘perpetual limited duty’ (or partial disability) in conjunction with the recent advocacy for ‘keeping patients on the job.’ In time, unless such patients are unable to return to full duty or significantly modified jobs, they too go on to persistent work adjustment problems with employers and increasing disability behaviors.

Certain musculoskeletal disorders have a predilection for becoming chronic disabling problems. Spinal disorders, particularly those affecting the low back, usually beginning as ‘sprains and strains,’ are more highly represented among chronic pain/disability work-related injuries than other musculoskeletal areas. Upper extremity non-neurocompressive complaints, particularly those termed repetitive motion or cumulative trauma disorders (CTD) also have a higher rate of developing chronicity, and CTD claims are known to be 1.8 times more expensive than non-CTD claims.^1–7 By contrast, lower extremity injuries, particularly if they involve fractures, tend to resolve more completely within a usual tissue healing period. In many ways, the more subjective the diagnosis and mechanism of injury, the greater the likelihood of symptom persistence.

Chronic spinal disorder (CSD) pain is not merely a function of incomplete healing after injury. Traditional medical efforts to treat and rehabilitate chronic back pain have often been met with poor outcomes. Past failed efforts to identify the source of, or treat, CSDs have resulted in the identification of ‘psychogenic’ or ‘functional’ pain, terms attributed to pain for which no physical substrate could be found and, therefore, for which psychological or ‘nonorganic’ causes were suspected. Back pain has been found to be subject to diverse influences including psychological difficulties (e.g. anxiety, substance use, depression), and social losses (e.g. inability to work, family role changes, financial stresses). Turk and Rudy⁸ set forth the biopsychosocial model of pain asserting that pain is engendered not only by physical insult, but also by cognitive, affective, psychosocial, and behavioral influences. Based on this biopsychosocial theory, CSD treatment considerations now go beyond the physical source of the pain to consider psychological and socioeconomic variables as well.

Much controversy exists regarding the development of chronic pain/disability syndromes after work-related musculoskeletal injuries. A variety of psychosocial host factors, secondary gain and socioeconomic predictors have been variably reported in the literature. Clinicians tend to focus on the nonphysiological aspects of pain persistence, regardless of the diagnosis, because of the reasonable assumption that bones, joints, and soft tissues have healed completely, even if imperfectly, in a finite period of time. While there may be persistent bony malalignment, joint degenerative arthritis or soft tissue scar, these changes are deemed ‘set in stone.’ They may result in some degree of permanent impairment. However, while the majority of injured workers (and a perceived greater percentage of patients without compensation) seem to recover in a timely fashion, a disturbingly large and costly group of chronic disability patients remain disabled and refractory to treatment over a substantial period of time. These patients tend to demand a significant preponderance of indemnity and medical costs, and if followed in most federal social systems for 15–20 years, represent the largest number of patients in every industrialized country who become permanently disabled for the longest periods of time. This is because the average age of work-related musculoskeletal injury developing permanent disability is in the mid-30s, much earlier than any other diagnostic entity producing such disability (with the possible exception of the much less common psychiatric disorders). For these chronic pain/disability patients, repeated passive therapy, manipulation, or surgical intervention has commonly been tried, but has failed to relieve symptoms and overcome disability. These patients tend to produce the most significant cost to society in terms of medical care, disability payments, and loss of productivity. As such, they provoke a great deal of concern and interest. It is this difficult group of patients, failures of ‘conservative care’ and/or surgery, for whom spinal functional restoration is intended.

Economic globalization may create dislocations of local economies. In industrialized countries such as the US, these dislocations cause major shifts in demand for workers in different labor-intensive industries. There are pressures on workers to develop skills to shift jobs within the changing job markets. Industry is incentivized to reject those workers unable to make the transition. There are similar incentives to minimize the appearance of unemployment and job dislocations by ‘disappearing’ less flexible employees from the national economy. When chronic disabling musculoskeletal disorders lead to long-term re-employment problems, employers may find it more convenient to convert them to ‘throwaway workers.’ This creates pressure to compensate such patients with public, rather than private financing. Since the 1960s, Social Security Disability Insurance (SSDI), more recently linked to medical benefits through Medicare, has been provided to such individuals under certain circumstances. There has been a recent exponential growth in acceptance of younger and potentially more able-bodied workers onto this national insurance scheme, which was initially intended for retirees. Although musculoskeletal problems have decreased as the reason for acceptance onto SSDI rolls, they remain above 35% of all accepted claims. The combination of musculoskeletal and mental health ‘stress claims,’ which are often intertwined, have become the majority of acceptances onto SSDI. Because of the young age (30–45 years) at which many of these workers are accepted for long-term payments, Social Security actuaries have referred to the problem as one of ‘early, early retirement.’ Current costs are US$100 billion/year for SSDI, up 150% since 1980. There are now nearly 9 million ‘disabled’ pre-retirement Americans on Social Security, more than double the number in 1980.⁹ There is huge variance from state to state, with twice as many claims accepted in the disability determination process, and three times as many after the administrative hearing process, in the high-acceptance states (New Hampshire, Maine) compared to low-acceptance states (District of Columbia, Texas). The younger the patient accepted, the more likely there is a musculoskeletal basis, and low back pain is the single largest cause of musculoskeletal disability. With disability payments currently representing 5% of the entire US budget, such payments are becoming an increasing drain on the Social Security funds that were initially intended solely for retirees. Failure of tertiary rehabilitation for chronic occupational spinal disorders leads inevitably to patients departing the employment statistics and transitioning to insurance schemes such as SSDI in ever-increasing numbers. Thus, tertiary rehabilitation becomes the leading prevention strategy against permanent loss of productivity and high social cost in US spinal disorder medical care.

Because of the multifactorial and subjective nature of chronic pain, traditional therapy has been less than fully effective in treating and rehabilitating CSD patients. As a result, medical approaches have evolved to accommodate this costly and complex phenomenon. There are several risk factors that can be used to guide the treatment of spinal disorders and pain based on the levels of treatment described below. The severity of the dysfunction must be considered. The severity of a musculoskeletal dysfunction is related more to the patient’s chronicity and level of disability than to the presumed causative event. While diagnoses (e.g. degenerative disc disease, facet arthropathy, disc disruption, segmental instability) may be important in identifying surgically treatable pathology, their relevance fades in chronic pain conditions in which patients have generally failed to respond to invasive procedures, or have been deemed unsuitable for surgery. In addition to the psychological factors, inactivity and disuse may play a major role. They may lead to the deconditioning syndrome, in which the injured spinal region becomes a ‘weak link’ connecting the body’s functional units. Deficits of motion, strength, and endurance interfere with physical performance of otherwise unaffected joints and muscles.^10–14 While the need for spine surgery is rarely so imminent that a trial of nonoperative therapy is not indicated, there is often a limited understanding of the levels and purposes of such care as a function of the severity of the problem.

No one has yet managed to identify the unique structural ‘pain generator’ in the majority of CSD patients. Description of such a site has eluded basic scientists, surgeons, internists, and psychologists, and probably will continue to do so. The obvious reason for this is that pain is a subjective central experience of multifactorial origin. With the source of the pain deeply submerged and inaccessible to visual inspection (similar to headache and chronic abdominal pain) the spine is subject to diverse influences such as psychological difficulty, social losses, and financial uncertainties. These ‘secondary phenomena’ tend to be ignored by the health provider who has no mechanism available to deal with these problems. As a consequence, a critical part of our understanding of spinal disability is lost. Since interdisciplinary experience is not usually part of most physician training, lack of conceptualization and resolution in the area of chronic spinal disability is to be anticipated.

QUANTIFICATION OF PHYSICAL DECONDITIONING

While a normal soft tissue, joint, or bony healing period will generally have occurred by the time a patient enters a period of chronic pain/disability, progressive deterioration of physical and functional capacity may still be in an early stage. Deconditioning occurs as a consequence of disuse and fear-related inhibition. The quantitative assessment of function is a vital aspect of developing an effective treatment program for disabling spinal disorders. In the extremities, there is relatively good visual feedback of physical capacity. Joints are easily seen and mobility subject to goniometric measurements, and the muscle bulk is subject to tape measurements. Right/left comparisons between a normal and abnormal side can frequently be made. In the spine, there is inadequate direct visual feedback of physical capacity. Yet, this deficiency has not been generally recognized by clinicians who often continue to rely on subjective self-report or physical measures that are either inaccurate or irrelevant. More accurate methods are necessary for objective quantification.^31–34 This information is discussed in greater detail in another chapter. However, for the focuses of this chapter, the author wishes to illustrate several aspects of quantification of function. In Figure 112.1, one sees the dual inclinometer method being used to measure spinal sagittal motion. In Figure 112.2, sagittal spine strength is being tested. The measurements of localized mobility and strength in the injured spinal region is termed physical capacity as it documents the ‘weak link’ deconditioning of an injured or involved area. This is contrasted with the concept of functional capacity, representing whole-person measurements. For whole-person functional measurements, lifting is a useful tool to assess lumbar (floor-to-waist) and cervical (waistto-shoulder) functional regions. The progressive isoinertial lifting evaluation (PILE) test is a simple and inexpensive way to accomplish such measurement as seen in Figure 112.3A.^35–37 Figure 112.3B demonstrates isokinetic and isometric (National Institute of Occupational Safety and Health) lift testing being performed.

Fig. 112.1 Subject being tested for sagittal flexion utilizing the dual inclinometer method. One inclinometer is placed over T12 while the other is placed over the sacrum.

Fig. 112.2 A trunk extension/flexion (TEF) testing device used to measure sagittal trunk strength isokinetically and isometrically. Computerized calculations from the measurement dynamometer of torques in foot-pounds are generalized, normalized for effective patient comparisons, by age, gender, and body weight.

Fig. 112.3 (A) The progressive isoinertial lifting evaluation (PILE) test uses simple milk cartons, standard-height shelves, and inexpensive weights added to a box with a fixed protocol. (B) A cable lifting device with a dynamometer permitting isometric and isokinetic lift assessment to a full range of motion (or selected ranges) from floor to above shoulder. Again, age, gender, and body weight normalization is common.

PSYCHOSOCIAL AND SOCIOECONOMIC ASSESSMENT

In a work environment, when injury is associated with compensation for disability, physical problems are rarely the only factor to be considered in organizing a treatment program. Many psychosocial and socioeconomic problems may confront the patient recovering from a spinal disorder, particularly if inability to lead a productive lifestyle is associated with the industrial injury. The patient’s inability to see a ‘light at the end of the tunnel’ may produce a reactive depression, often associated with anxiety and agitation. The musculoskeletal injury itself may be associated with emotional distress as expressed by rebellion against authority or job dissatisfaction. Poor coping styles associated with reaction to stress or underlying personality disorders may be manifested in anger, hostility, and noncompliance directed at the therapeutic team. Organic brain dysfunction from age, alcohol, drugs, or a supposedly minor head injury, or limited intelligence may produce cognitive dysfunctions that make patients difficult to manage and refractory to education.

Many CSDs exist within an occupational ‘disability system.’ Workers’ compensation laws were initially devised to protect workers’ income and provide timely medical benefits following industrial accidents. In return for providing these worker rights, employers were absolved of certain consequences of negligence, generally including cost-capped liability for any injury, no matter how severe, and set by state or federal statute. Unfortunately, certain disincentives to recovery may emerge. One outcome of a guaranteed paycheck, while Temporary Total Disability persists, is that there may be limited incentives for an early return to work. A casual approach to surgical decision-making and rehabilitation may lead to further deconditioning, both mental and physical, making getting well more problematic. Complicating matters even further is the observation that no group (other than the employer) has a verifiable financial incentive to rapidly return patients to productivity. In consequence, an assortment of health professionals, attorneys, insurance companies, and vocational rehabilitation specialists are involved with limited motivation to combat foot-dragging on the disability issue.

Early efforts to distinguish between ‘functional’ (nonorganic) and ‘organic’ pain did not meet with success. The complex nature of chronic pain makes it difficult to categorize component factors as purely physical or psychological. Chronic pain must be understood as an interactive, psychophysiological behavior pattern wherein the physical and the psychological overlap. The focus of psychological evaluation of the patient with pain must shift away from ‘functional’ versus ‘organic’ distinctions to the identification of psychological behavioral motivators for each patient. These characteristics impact a patient’s disability and his or her response to treatment efforts. Treatment planning and the prediction of favorable treatment outcome are facilitated by first identifying and then controlling these factors.

The assessment goal is to obtain a DSM-IV psychiatric diagnosis, particularly Axis I or II, to assist the interdisciplinary treatment team in understanding and dealing with the preexisting and post-traumatic barriers to recovery. Depression, anxiety, substance use, and stress disorders (Axis I) frequently accompany CSDs, as do preexisting personality disorders (Axis II) and childhood abuse experiences. Socioeconomic factors related to compensation for the injury (or its premature cessation), may be factored in with the variety of problems associated with education, transferable skills or family distress. Multidisciplinary medical treatment may include psychiatric interventions to detoxify and stabilize on psychotropic medication before the interdisciplinary team becomes involved in a treatment approach that requires physical training, education, and counseling as a significant component. Individualizing pain management, stress controls, and education, as well as guidance towards future return to productivity, is a vital outgrowth of the psychosocial assessment.

TERTIARY INTERDISCIPLINARY FUNCTIONAL RESTORATION TREATMENT

The physiologic approach to the deconditioning syndrome involves therapeutic exercise to address mobility, strength, endurance, cardiovascular fitness, and agility/coordination. The exercises must progress to involve simulation of customary physical activities to restore task-specific functions. Such exercises must be focused at the specific functional unit that has become deconditioned, and ultimately be generalized to whole-body functions.

Dynamic muscle training, which has been shown to be the most efficient method of training, can be employed in CSDs. It involves three basic modes: isotonic, isokinetic, and psychophysical (free weights).³⁸ Isotonic exercises are those in which the same force is applied throughout the dynamic range and is often inappropriately used for exercises in which a changing lever arm actually alters the applied torque. This type of exercise is most often associated with the variable resistance devices, utilizing a cam to equalize muscular demands throughout the dynamic range of motion.

Secondary effects of a functional restoration program are also critically important. Physical training appears to have a specific beneficial effect on pain (possibly through increased synthesis of specific neurotransmitters) and has been demonstrated to prevent scarring and adhesions while improving cartilage nutrition. Mobility appears to be the key, which can be done initially through passive and then subsequently through active means. Development of normal to supernormal strength and endurance in muscles acting around a joint may be of benefit in protecting a joint having sustained cartilage damage or instability due to ligamentous incompetence. This development of protective muscular mechanisms is particularly important when a complete return to normal joint architecture can no longer be anticipated.

In the early stages of the program, mobility exercise is the most important aspect of physical training. Muscle training requires putting the affected joint (or spinal segment) through a full range of motion to be effective. Endurance training generally accompanies or follows strength training. Stretching of joints as much as possible, sometimes accompanied by use of antiinflammatory medication and/or corticosteroid injections, is an important first step in the physical rehabilitation process. Yoga-type exercises, with the holding of postures at greater length than many patients are used to, including use of breathing to encourage relaxation, can be an effective tool. It is always a part of lifelong learning as a component of the fitness maintenance program.

Strength training is generally done with weight machines. In the functional restoration program at PRIDE (Productive Rehabilitation Institute of Dallas for Ergonomics) the quantification of function using tests described in the previous chapter develops data that are fed into a computer system, which calculates suggested levels of training based on age, gender, body weight, and anticipated activity levels. A stepwise program to increase from the test-determined starting levels, checked periodically with repeat testing, is utilized. In Figure 112.4A, a torso rotation device to strengthen oblique spinal and abdominal musculature is utilized. Figure 112.4B shows a pull-down device for shoulder strength that also affects musculature in the cervical area (paraspinal muscles, trapezii, and scalene muscles). When a fitness maintenance program is developed for patients to continue with what they have learned during their rehabilitation, a Roman chair (Figure 112.4C) may be useful for extensor strengthening of all of the spine muscles from cervical to lumbar area, including the gluteal/hip muscles.

Fig. 112.4 (A) A torso rotation strength device using weight stacks with training levels individualized by patient testing scores, age, gender, and body weight. (B) A shoulder pull-down device is used to help strengthen the neck and shoulder girdle musculature. (C) A Roman chair device can be used at home or in a fitness center to help maintain strength of the spinal extensors and gluteal/hip musculature.

In the physical therapy areas, patients train the injured ‘weak link’ area of the spine. This area must be isolated and focused on by the therapists in a supervised environment, because patients are generally inhibited by fear-avoidance or prolonged disuse. Most training devices are therefore specific to a certain injured part of the body (e.g. cervical spine, lumbar spine, knees, etc.). In the occupational therapy area, patients focus on coordinating the injured ‘weak link’ with other body parts to achieve full-person functional activities. The performance of such functional activities predominates, encouraging such capabilities as lifting, bending, reaching, climbing, or twisting. An obstacle course of multiple devices used to demand patient agility in performing functional tasks can be very useful. Figure 112.5A demonstrates a patient who combines functional tasks, including lifting, carrying, and climbing, with a relatively simple stair device. Figure 112.5B shows wall-mounted devices that can be used to enhance upper extremity motion for patients with cervical CSDs with radicular problems, or associated upper extremity disorders. In the later stages of functional restoration, the occupational therapists supervise a ‘ready room’ allowing actual simulation of work tasks, such as truck driving, clerical work, construction work (carpentry, electrical, plumbing, etc.) and other manual tasks.

Fig. 112.5 (A) Shows a patient engaged in functional tasks in the occupational therapy gym, combining carrying, lifting, and climbing tasks. (B) Shows patients engaged in upper extremity functional tasks.

Psychosocial interventions in functional restoration

The patient undergoing CSD rehabilitation is customarily one who has issues of prolonged disability, associated with longstanding pain. Traditional approaches have focused on ‘pain management’ which is intended to teach patients about coping with pain and modifying self-defeating behaviors. The essential flaw in solely utilizing this approach has been the continued focus on the patient’s self-report of pain, which is ultimately self-serving and unmeasurable. In functional restoration, the physician emphasizes the return to function and the setting of specific goals to achieve this return, recognizing that improved physical capacity, decreased stress and tension, and return of self-esteem and self-confidence will probably reduce the patient’s pain perception. The rehabilitation process itself may be a stressful and physically painful ‘spring training’ experience for the physically and psychologically deconditioned individual. One-half of the program is devoted to education and counseling, and incorporates supportive and inspirational interventions to help the patient to successfully complete rehabilitation.

SUMMARY

Chronic spinal disorder pain/disability is a very costly and serious phenomenon in most industrialized countries. Although the majority of individuals will experience back pain in their lifetime, most will see their symptoms remit within a short time. A minority will experience ongoing pain and physical disability well beyond the expected healing time. This minority generates 90% of the cost associated with treating spinal disorders when measured over more than 1–2 decades. Our understanding of CSDs has evolved over the years from a binary classification of pain as either psychogenic or physically based, to a multifactorial model of interlaced phenomena contributing to the pain experience, including biological, social, and psychological influences. As a result of the evolution in our understanding of chronic pain, applicable treatments have also evolved, culminating in the genesis of an eclectic mix of pain clinics across the United States, with treatments geared toward treating the physical substrate of pain as well as addressing psychological and socioeconomic factors. Tertiary treatment is indicated for patients experiencing chronic disability. This level of care involves an intense, interdisciplinary treatment team approach focusing on reestablishing physical function and helping the patient manage the psychological and socioeconomic barriers to recovery. Functional restoration is a form of tertiary treatment which uses objective evaluations of a patient’s physical, functional, and emotional capacity to organize a physician-directed interdisciplinary team-treatment approach whose primary goal is to improve functional status. The functional restoration approach differs from other tertiary chronic pain treatment modalities through an emphasis on physical reconditioning and improved function over the goal of pain relief alone. Traditional chronic pain management programs, however, place pain relief as a primary goal regardless of a patient’s activity level or medication regimen. Patients who fail to respond to both surgical and less invasive levels of nonoperative treatments for CSDs may be referred to functional restoration rehabilitation. In most cases, this is the final level of care before patients reach a medical treatment endpoint, known in most workers’ compensation venues as maximum medical improvement (MMI). This is the point at which all reasonable medical treatments designed to improve or cure the condition have been offered or provided. At this point, it is the patient’s decision whether to return to productivity and decrease health utilization, or to pursue efforts at obtaining compensation for permanent disability through one of the public (SSDI or SSI) or private (LTD) insurance schemes that they may be eligible for. The complex interaction of financial, psychosocial, and physical factors affect the individual’s ultimate decision, and determine the socioeconomic outcomes of a functional restoration program.