The Role of the Physical Therapist Assistant in Physical Assessment

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The Role of the Physical Therapist Assistant in Physical Assessment

Candy Bahner

As any prospective or current student in the field of physical therapy is aware, changes in the profession are emerging rapidly. In an effort to bring physical therapy professionals to the “health care table” for discussion of legislative, regulatory, and reimbursement issues, the leaders of our profession are striving for standardization of terminology and recognition and application of evidence-based practice.4 Needless to say, controversy or at least animated debate occurs among interested parties any time such an in-depth self-scrutiny of a profession takes place. One significant element of this debate in physical therapy revolves around the physical therapist assistant’s (PTA’s) role in the profession, including how the PTA participates in the administration of the physical therapy plan of care, including selected interventions, data collection techniques, and the terminology associated with the PTA’s role. The purpose of this chapter is to summarize available standards and guidelines associated with the PTA’s role in physical therapy treatments and to discuss techniques and implications of selected interventions and their associated data collection techniques to be utilized for the patient with a musculoskeletal condition.


Guide to Physical Therapist Practice, Second Edition

The Guide to Physical Therapist Practice, second edition (the Guide) is a tool that was developed by the American Physical Therapy Association in part to “…describe physical therapist practice in general; …standardize terminology used in and related to physical therapist practice; …delineate preferred practice patterns that will help physical therapists…promote appropriate utilization of health care services; [and] increase efficiency and reduce unwarranted variation in the provision of services….”4 The stated purpose of the Guide reads, in part, that it is: “…a resource not only for physical therapist clinicians, educators, researchers, and students, but [for] health care policy makers, administrators, managed care providers, third-party payers, and other professionals.”4 According to the Guide, the definition of the PTA is: “A technically educated health care provider who assists the physical therapist in the provision of selected physical therapy interventions.”4 Assessment is defined as “The measurement or quantification of a variable or the placement of a value on something.”4 Further, the Guide states, “Assessment should not be confused with examination or evaluation.”4 Examination involves preliminary gathering of data and performing various screens, tests, and measures to obtain a comprehensive base from which to make decisions about physical therapy needs for each individual patient, including the possibility of referral to another health care provider. Evaluation is the specific process reserved solely for the physical therapist (PT), in which clinical judgments are made from this base of data obtained during the examination.4

The Clinical Performance Instrument

The Clinical Performance Instrument (CPI), a uniform clinical education grading tool developed by the American Physical Therapy Association,5 includes the following criteria related to the PTA’s role in clinical problem solving and judgments, data collection, and assessment techniques:

image “Participates in patient status judgments within the clinical environment based on the plan of care established by the physical therapist.” (criterion #9)

image “Obtains accurate information by performing selected data collection consistent with the plan of care established by the physical therapist.” (criterion #10)

image “Discusses the need for modifications to the plan of care established by the physical therapist.” (criterion #11)

A Normative Model of Physical Therapist Assistant Education: Version 2007

A Normative Model of Physical Therapist Assistant Education: Version 20072 (the Model) is a consensus-based document developed by the American Physical Therapy Association. Briefly, the Model was designed to provide a representation of all of the elements that provide the foundation for the development and evaluation of educational programs preparing PTAs.2 According to the Model, PTAs “…implement selected components of patient/client interventions and obtain data related to that intervention; make modifications in selected interventions either to progress the patient/client as directed by the physical therapist or to ensure patient/client safety and comfort.”2

Interestingly, the Model includes the following five physical therapy performance expectation themes:

The Interventions physical therapy performance expectation theme is subdivided into the following seven sections:

Each performance expectation theme includes educational outcomes, terminal behavioral objectives, and instructional objectives to be achieved in the classroom and clinic.

Frequently, the response to the question about the difference between PTs and PTAs is simply, “PTAs don’t do evaluations.” Considering the elements of judgment and decision making involved with evaluation and from the preceding discussion, does this imply that the PTA does not exercise judgment or make decisions? Of course not. However, the judgments and subsequent decisions of the PTA are made within the context of the existing physical therapy plan of care, established by the supervising PT through the examination and evaluation process. This process occurs on an ongoing basis.23 Without effective data collection and reporting by the PTA, the PT would lack key information on which this data management process relies.23

It may be helpful to consider the functions of data collection and patient management as integral parts of managing a patient’s physical therapy case, which is a dynamic process as illustrated in the APTA’s “Problem-Solving Algorithm Utilized by PTAs in Patient/Client Intervention” (see Figure 1-1).2

This discussion of specific assessment techniques and issues begins with two conditions frequently encountered among patients with musculoskeletal involvement: inflammation and pain.


What Is Inflammation?

Inflammation is a living organism’s first response to injury or disruption of normal processes. It is a normal response, and actually can be considered the body’s immediate trigger for healing. Inflammation involves the responses of several body constituents, including vascular components, fluid and semifluid (humoral) substances, and neurologic and cellular reactions. Inflammation that does not resolve within expected time frames may develop into a chronic state (as a result of either abnormality in the individual’s immune or inflammatory response or as a result of prolonged, continuous, or repeated exposure to the injurious agent). Chronic inflammation (considered a pathologic condition) may result in secondary complications or permanent changes in the makeup of the involved tissue, including scarring or granulomatosis. Two important factors must be kept in mind: that inflammation is a normal and necessary response to trigger tissue healing, and that unresolved (chronic) inflammation may lead to permanent and undesired tissue changes. Therefore it is imperative for the PTA to monitor changes in the inflammatory response of the area being treated. In addition, extreme changes in the appearance of inflammation may signal the onset of serious complications, necessitating further evaluation by the PT or, in some cases, referral to the physician for immediate medical evaluation.

As discussed elsewhere in this book, certain physical agents are employed to control (but not eliminate) the acute inflammatory response or accelerate it, thus moving the healing process along. Depending on the degree of inflammation present, certain physical agents may be contraindicated. So how does the PTA differentiate between normal inflammation and an inflammatory reaction indicating the potential for contraindicated procedures or serious complications?

The commonly accepted and normal (cardinal) signs and symptoms of inflammation are localized heat, redness, swelling, and pain with a resultant loss of function in the injured area. Temperature and redness are discussed here in relation to the PTA’s role in collecting data and communicating concerns appropriately to the PT. The discussion of the assessment of edema and pain are discussed in separate sections.

Acute versus Chronic

Under normal circumstances, signs of acute inflammation persist for 4 to 6 days, assuming the precipitating condition, agent, or event is removed. In the initial 48 hours after tissue injury, the observable signs of inflammation are associated with the normal inflammatory vascular response to trauma.19 An important distinction to make is the definition of acute versus chronic in relation to the actual cause of injury or trauma. It is common for sources to refer to these tissue states in terms of time frames only, with the acute phase lasting 4 to 6 days and the chronic phase lasting 6 months to 1 year.19 A more useful way to consider inflammation incorporates the concept of whether there is real or impending tissue damage present. The significance of this designation relates to the PTA’s role in determining whether, based on the stage of inflammation present, certain interventions may be implemented or are contraindicated.28 If an intervention normally results in an inflammatory reaction, it is contraindicated when the tissue is in an acute inflammatory state that indicates ongoing tissue damage. For example, in the presence of acute inflammation (indicating an active state of injury, tissue damage, or early tissue healing), dynamic resistance exercises are contraindicated.19 However, the PTA also may proceed with interventions included in the plan of care that accelerate the inflammatory process if it has been determined that the original causal agent or condition no longer results in ongoing tissue damage. Contraindications related to specific diagnoses or associated with the application of specific physical agents are discussed elsewhere in this book.

During interventions involving range of motion (ROM) activities, the PTA also may note that the patient reports pain before tissue resistance is felt (before end ROM); this is an indication of acute inflammation.19 Pain reported at the same time end ROM is reached is indicative of a subacute inflammatory state, and pain reported as a stretching sensation at the limit of ROM is a sign of inflammation in the chronic state.19 If the PTA determines that the established plan of care includes interventions that are not appropriate for the apparent stage of inflammation, the PT must be consulted to adjust goals, time frames, or possibly the plan itself to ensure that the treatment does not contribute to a prolonged or abnormal state of inflammation.


The PTA must be able to differentiate between expected temperature responses in a normal inflammatory response versus abnormal responses. A normal increase in temperature is local and initially mild to moderate (compared with the contralateral anatomic region) versus a more pervasive change, which may manifest as significant either as compared with the contralateral side or as a systemic increase in temperature (fever). In the former case joint effusion may be present; the latter may represent a systemic response to the injury (e.g., infection) or an unrelated condition, such as an acute disease process (e.g., flu). Either of these situations warrants action on the part of the PTA. In the presence of systemic infection, the patient’s ability to participate in the physical therapy plan is affected. Because of the exclusive one-on-one time traditionally associated with physical therapy care, it is not uncommon for the PTA to be the member of the health care team who provides important pieces to the puzzle of the patient’s total health or illness picture.

Both the degree of temperature elevation and duration of fever are relevant to diagnostic processes when elevated body temperature is evident. During the initial examination and evaluation, any abnormality in temperature, either locally or systemically, should be noted. The PTA’s role is then to note deviations from the examination findings, determine the length of time the fever has been present (through patient interview) and note other possible related signs and symptoms: rash, cough, complaints of sore throat, and so on. Also it should be noted if the patient reports any pattern of temperature changes, because this may have diagnostic implications for the PT or physician. Immediate implications include whether or not exercise or other interventions may be contraindicated and to what extent infection control issues must be addressed. Normal adult body temperature (oral measurement) ranges from 96.8° F to 99.5° F (36° C to 37.5° C).26 Temperature is affected by factors including age, time of day, emotions/stress, exercise, menstrual cycle, pregnancy, external environment, measurement site, and ingestion of warm or cold foods.26 Clinical signs and symptoms of fever vary based on the underlying cause and stage and may include general malaise, headache, increased pulse and respiratory rates, general chills, shivering, piloerection, loss of appetite, pale skin, nausea, irritability, restlessness, constipation, sweating, thirst, coated tongue, decreased urinary output, insomnia, and weakness.26 In the case of the presence of fever, the PTA must gather the related data, document it, and report it to the supervising PT. The data and report should include adequate information to enable the PT to respond appropriately, either in terms of immediate modification to the physical therapy plan of care or consultation with the medical team.

Fever and Lymph Nodes

Another condition that may become readily apparent to the PTA in the course of carrying out elements of the physical therapy plan of care is tenderness or exquisite pain in particular regions of the body. The presence of tender or enlarged lymph nodes is of particular concern to the PTA who is performing soft-tissue interventions on a patient with an elevated body temperature (or otherwise). Figure 2-1 provides a visual reference for the location of lymph nodes. PTAs using hands-on techniques such as soft-tissue massage and manual stretching are incidentally afforded the opportunity during the course of treatment to assess for the presence of unusual conditions in areas of lymph node clusters (e.g., in the neck and axilla). Because these symptoms can signify the presence of potentially serious pathologic conditions, the presence of pain, tenderness or enlargement of lymph nodes are situations in which the PTA must consult with the supervising PT to pursue medical follow-up for definitive diagnosis.14 In addition, certain interventions are considered contraindicated if the patient has an underlying pathology related to changes in the lymph nodes.


Redness (erythema) is a normal component of the inflammatory reaction. The PTA must be alert to abnormal or unexpected changes in skin color, which may indicate the presence of secondary complications or underlying pathologies. Redness may be considered normal when it is noted in the immediate area of injury and is associated with local temperature changes. Depending on the patient’s pigmentation, color changes may appear in tones other than red.

Unexpected findings in terms of changes in skin color should be reported to the supervising PT for further evaluation. These changes include rashes or redness that appear as a streak originating from the site of injury. Red streaks may indicate an acute inflammation caused by a bacterial infection (streptococci, staphylococci, or both), resulting in acute inflammation of the lymph vessels.14 Redness along with superficial tenderness and hardness (induration) of the area may be a sign of superficial thrombophlebitis.14 These findings should be reported to the supervising PT because they may be a precursor to more serious conditions. A loss of skin color (paleness or pallor) associated with temperature changes, edema, or pain may be indicative of an occlusion in a blood vessel and warrants immediate medical referral. A commonly used quick assessment technique to rule out the presence of a deep vein thrombosis (DVT) is Homans’ sign, performed by gentle passive stretching of the ankle into full dorsiflexion and assessing for pain in the calf. Some clinicians also incorporate a gentle squeezing of calf musculature during the passive dorsiflexion to assess for tenderness. Other structures that are stretched during this test include the calf muscles and the Achilles tendon; thus a positive Homans’ sign may be noted in error if a patient has tightness or inflammation of these structures. Although Homans’ sign is still commonly assessed, it is considered an insensitive and nonspecific test, and is present in less than one third of all patients with a documented DVT, and more than 50% of patients with a positive Homans’ sign do not have evidence of venous thrombosis.14 Furthermore, a serious potential complication of a DVT is that a piece of the coagulated blood (the clot) may break free from the inside of the vessel wall as a result of the test (or otherwise) and travel through the bloodstream, lodging in a pulmonary artery, causing a life-threatening condition (pulmonary embolism). Therefore it is recommended that the PTA refrain from conducting the Homans’ test and be alert to the risk factors and the clinical signs and symptoms of a DVT as outlined in Box 2-1 and report these findings to the supervising PT for further investigation and possible immediate medical referral. The PTA should note that signs and symptoms are the same for a PE and a DVT.


From Goodman CC, Snyder TE: Differential diagnosis for physical therapists screening for referral, St. Louis, 2007, Saunders Elsevier, p. 312.

Furthermore, the PTA should be aware of differences in superficial skin changes based on the patient’s skin color. In other words, these findings in individuals with darkly pigmented skin may be less obvious and do not manifest as the same changes in skin tones as with light-skinned individuals. A critical element to be included in the lab practice and skill development of the PTA student is exposure to a number of normal subjects of different body types, skin tones, and so on (often represented within a classroom population of adult learners). By observing and practicing on different subjects, the PTA student develops an awareness of normal variations, which will subsequently enhance his or her ability to recognize differences or abnormalities in a patient population.


Because edema and its management have significant implications in the practice of physical therapy, the entry-level PTA should develop the ability to recognize the signs and symptoms of edema, and to effectively and efficiently measure and document it.

For purposes of this text, the focus is on localized edema, resulting from injury or trauma to musculoskeletal tissue or structures. Other terms and conditions are defined or discussed in relation to the PTA’s responsibility in the event unrelated or unexpected conditions are discovered.

Edema refers to excessive pooling of fluid in the spaces between tissues (interstitial spaces).14 In relation to patients with orthopedic injuries or conditions, the main consideration for assessment by the PTA is measurement of the edematous part or extremity. Typically, the technique used to measure edema in an extremity is straightforward—use of a tape measure to obtain circumferential dimensions of the involved part. The data must be reliable and the measurement reproducible, regardless of who is conducting the assessment. To ensure this level of consistency, the PTA must use precisely the same landmarks as the evaluating PT. Specifically, palpable bony landmarks must be used as the starting standard reference point; then circumferential measurements can be taken at determined distances from that point. For example, to measure the lower leg, circumference measured with the tape measure at the inferior pole of the patella may be used as a reference point, with measurements then taken every 2 inches distally and at the ankle. One note of caution, the PTA must be careful to not pull the tape measure too tight when performing this skill. The skin should not have an indention if performing correctly. An example of a flow chart for recording circumferential measurements of the upper extremity is provided in Table 2-1.

Table 2-1

Sample Format for Documenting Edema

UE Right Left
Axilla _______inches _______inches
4” above elbow _______inches _______inches
2” above elbow _______inches _______inches
Elbow _______inches _______inches
2” below elbow _______inches _______inches
4” below elbow _______inches _______inches
Wrist _______inches _______inches

A standard for elbow could be from the cubital fossa around the elbow, crossing the olecranon process; a standard for wrist could be just distal to the radial and ulnar styloid processes.

A figure-of-eight technique may be used at the ankle to ascertain a gross estimate of generalized ankle edema.12,22,31 Refer to Box 2-2 for the steps involved in this procedure.

BOX 2-2   Technique for Figure-of-Eight Edema Measurement of Ankle

1. Position the patient in a long sitting position so that the lower leg is supported and the ankle is in a neutral position.

2. Mark the following landmarks with a skin pencil: tuberosity of the navicular (palpable projection on the anteromedial aspect of the hindfoot); base of the fifth metatarsal; distal tip of the medial malleolus; distal tip of the lateral malleolus; and tibialis anterior tendon.

3. Place the (0) edge of the tape measure midway between the tibialis anterior tendon and the lateral malleolus.

4. Wrap the tape medially across the instep (bottom surface of the foot), and place just distal to the navicular tuberosity.

5. Draw the tape across the arch of the foot, winding it back to the dorsum of the foot just proximal to the tuberosity (base) of the fifth metatarsal.

6. Cross back over the tibialis anterior tendon.

7. Wrap the tape measure around the ankle, drawing it just distal to the tip of the medial malleolus, crossing the calcaneal (Achilles) tendon and drawing the tape measure just distal to the lateral malleolus, back to the starting point.

8. For consistency, it is recommended that this process be repeated three times, with the average of the three measurements recorded.

Adapted from Magee DJ: Orthopedic physical assessment, ed 5, St. Louis, 2008, Saunders Elsevier; Tatro-Adams D, McGann S, Carbone W: Reliability of the figure-of-eight method on subjects with ankle joint swelling, J Orthop Sports Phys Ther 22(4):161-163, 1995; Esterson PS: Measurement of ankle joint swelling using a figure of 8, J Orthop Sports Phys Ther 1(1):51-52, 1979.

Another technique used to obtain a quantitative measure of edema in a limb involves immersing the limb into a specially designed container of fluid (a volumeter) and measuring the amount of water displaced.20 Karges and colleagues17 established correlations between different techniques of volumetric measurement but also emphasized the importance of ensuring reliability of the data for a given patient, in terms of employing a consistent technique for edema measurement of the same patient. In other words, as stated, the PTA must use the method of measurement, employing the same technique chosen by the evaluating PT.17,20

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