Quantification of Physical Performance Ability

Quantification of Physical Performance Ability

Steven Yeomans

Craig Liebenson

Richard Nicol


Functional capacity and physical performance evaluations have become an important part of the physical examination of work-injured and chronic pain patients.1,2,3 This unique evaluation is needed because traditional examination methods such as orthopedic, neurologic, and imaging tests are able to accurately diagnose the cause of pain in only approximately 10% of patients.4 When advanced imaging modalities are used, an excessive amount of coincidental findings (high false-positive rate) unrelated to the patients’ condition or prognosis are uncovered.5,6,7,8,9,10 Amazingly, most tests used in the physical examination of musculoskeletal patients are unreliable. For instance, orthopedic tests such as Kemp’s test or Patrick Fabere test have not been shown to be reliable or to have predictive validity.11,12,13 To avoid basing treatment decisions on often-misleading imaging procedures, unreliable orthopedic tests, or merely on the patient’s subjective self-report of symptoms, the focus of evaluation has gradually been shifting toward identification of functional or physical performance deficits.1,14,15,16,17,18,19

One exception is that with the use of diagnostic injections at least 50% of chronic spine pain patients presenting to specialist diagnostic centers can have the pain generator successfully identified.11,12,20 However, the cause of the tissue’s sensitivity may not be revealed and therein lies the added value of both physical performance and functional testing in such patients.

Psychosocial factors are also very important in caring for chronic pain patients and predicting which acute patients are most likely to have chronic pain. However, physical performance testing may reveal salient impairments that were at least partially responsible for the pain in the first place.21 This can help to focus the patient on the important goal of reactivation and functional restoration.

The physical examination can be used for diagnostic, prescriptive, and outcome purposes. The examination of physical performance ability (PPA) is a key part of the physical examination because it can help identify specific impairments responsible for biomechanical overload of various pain generators.22 Additionally, it can identify impairments related to specific functional limitations that affect an individual in performing their daily tasks at home, work, or sport.23,24 This chapter discusses the rationale (why), indications (when), methods (what), and implementation (how) related to performing a PPA assessment.


The World Health Organization (WHO) has operationally defined function in its International Classification of Functioning, Disabilities, and Health (ICF) document.25 Most significantly, ICF is able to describe the health experience of a person, addressing aspects of this experience such as functioning, impairment, participation, and contextual factors. In ICF, functioning relates to physiologic function, body structure, and activities and participation. The description of disability comes from the assessment of impairment, activity limitation, and participation restrictions. Adding context to a person’s health experience are the environmental and personal factors. These include facilitators and barriers. Factors that improve function or reduce disability are facilitators, whereas factors that limit functioning or create disability are barriers.25

There are many tools available to assess activity intolerance and tests of actual patient’s general functional abilities such as walking, reaching, and carrying. In contrast, some specific functional deficits may only be found on clinical examination and may or may not be related to the patient’s symptoms or functional abilities.26,27 In this case it is the clinician’s perception that influences the significance of the findings. The PPA test, detailed in this chapter, is mainly a test of such impairments or specific functional deficits. Because the relationship between specific functional impairments and disability is indirect, the PPA evaluation is but one tool in the evaluation of patients.

Evaluation of PPA does not substitute for the traditional history and examination of orthopedic, neurologic, or vital signs. Diagnostic triage to identify patients with “red flags” of serious disease and nerve root compression syndromes is a first step in evaluation and requires a focused approach (see Chapter 6).28 When “red flags” are present imaging or laboratory investigations are indicated. If imaging tests are ordered in the absence of “red flags,” they can be misleading because of their high false-positive rates for clinically insignificant age-related degenerative findings.5,7,9,29,30

Because less than 10% of acute patients can receive an accurate, specific diagnosis, most recent guidelines label the remaining 90% as having “nonspecific” low back pain (LBP).28,31,32,33 This failure to more accurately diagnose or classify 90% of LBP has not been deemed a limitation because the condition’s favorable natural history has been touted. Recent epidemiologic studies show that the course of these “nonspecific” LBP cases is longer-lasting and more recurrent than
previously supposed.34 The use of the “nonspecific” label has been interpreted to mean that the majority of patients are a homogeneous group who share a uniform clinical picture and prognosis. However, what it more likely indicates is that we are not very good at subclassifying a heterogeneous group into discrete groups requiring individualized care.35,36 Current attempts at providing better care for LBP patients have emphasized improving our ability to diagnose or classify patients into meaningful subgroups (see Chapter 9).37,38,39,40,41,42,43,44,45,46,47

The most important reasons for performing a PPA evaluation are to identify treatment targets—prescriptive—and establish baseline levels of functional impairment from which to judge future progress by—outcomes. Establishing a “functional diagnosis” is an invaluable clinical guide that can influence treatment decisions and steer care toward meaningful end points of care. The PPA evaluation should focus on relevant functions that can be safely and reliably measured. Where normative databases exist, this is most helpful and, whenever possible, using tests that include quantification is ideal for outcomes-based reporting. The most valid tests are those that most closely resemble the actual way we use our bodies in performing activities of daily living (ADLs). The most valued characteristic of a functional measure is its utility. The utility or usefulness of the procedure is the degree to which it meets the needs of the patient, referrer, and payer. Five issues pertaining to a test’s utility have been described in hierarchical order (Table 10.1).48,49

High-tech instrumentation and dynametric assessment of the low back have been considered the “gold standard” of lumbar spine functional assessment. This is largely because of their reliability and reproducibility. However, the validity of some of the high-tech testing approaches has become a source of controversy.50,51,52 Matheson says, “the interpretation of the test score should be able to predict or reflect the evaluee’s performance in a target task.”53 If an effort factor can be measured, this will help unmask a malingerer. However, as Dvir has pointed out, this is very difficult to accomplish, especially with strength testing.54

Table 10.1 Key Features of Functional/Performance Tests Utility

  1. Safety: Given the known characteristics of the patient, the procedure should not be expected to lead to injury

  2. Reliability: The test score should be dependable across the evaluators, patients, and the date or time of administration

  3. Responsiveness: The test should detect clinically meaningful change in a condition or attribute over time over and above random improvement

  4. Validity: The interpretation of the test score should be able to predict or reflect the patient’s performance in a target work setting

  5. Practicality: The test should be easy to administer and interpret. The cost of the test procedure should be reasonable. Cost is measured in terms of the direct expense of the test procedure plus the amount of time required of the patient, plus the delay in providing the information derived from the procedure to the referral source

Republished with permission of Hart DL, Isernhagen SJ, Matheson LN. Guidelines for functional capacity evaluation of people with medical conditions. J Orthop Sports Phys Ther. 1993;18(6):682-686. Permission conveyed through © Clearance Center, Inc.

Grabiner et al have demonstrated that normal strength measurements from a high-tech approach do not necessarily correlate with normal human function.50 In this study, electromyography (EMG) was used during isometric trunk extension. The results revealed decoupling, or asymmetric lumbar paraspinal muscle activity, was present in LBP subjects who were considered normal on high-tech dynametric testing. This decoupling phenomenon was able to differentiate between pain and nonpain subjects. This study suggests that musculoskeletal function involves not only strength but also coordination during the performance of a specified task. Because spinal movement and coordination use complex neuromuscular functions, simple strength assessment by high-tech dynamometer does not necessarily correlate with assessment of spinal function.

As Lewit puts it, “… in many fields of medicine the importance of changes in function is now well recognized, whereas in the motor system, where function is paramount, this fundamental aspect is rarely considered. However, the functioning of the locomotor system is extremely complex, … and diagnosis of disturbed function is a highly sophisticated proceeding carried out, as it were in a clinical no man’s land.”55

LaRocca in a presidential address to the Cervical Spine Research Society Annual Meeting in December 1991 criticizes his colleagues for jumping to a psychological diagnosis when they cannot find a structural cause for a patient’s persistent pain: “… The error here
is the automatic leap to psychology. It assumes that all organic factors have been considered, when in reality the clinician’s appreciation of the complexity of such factors is often severely limited.”56 Newton and Waddell said, “There is no convincing evidence that isokinetic or any other iso-measure has greater clinical utility in the patient with low back pain than either clinical evaluation of physical impairment, isometric strength, simple isoinertial lifting or psychophysical testing.”51

At the present time, the quality of high-tech tests is not demonstrated sufficiently to lead to the abandonment of lower-tech qualifiable tests of spinal function. Many reliable low-tech ways to identify functional pathology have been identified. The inclinometer is an example of a very simple tool that can safely provide a great amount of valid and reliable information. Often a patient’s musculoskeletal function cannot be quantified. However, qualifiable tests may be performed that give insight into clinically relevant muscle imbalances, joint stiffness, postural dysfunctions, and movement incoordination.38,40,42,57

Many chiropractors, osteopaths, and manual therapists use tools that lack reliability such as motion palpation of the accessory movement of joints—commonly called “end feel.” Lack of reliability may be caused by a multiplicity of factors58,59,60 and is not a sufficient reason to abandon a test that is simple, time-efficient, and theoretically able to test something in a way not possible with more accurate or sophisticated means. However, such tests must at least be targeted for research into their reliability and validity or their users risk being considered “cultists.”61,62

Rissanen et al found that nondynamometric tests correlated better with pain and disability than did isokinetic tests.39,52 They concluded, “The non-dynamometric tests are still useful in clinical practice in spite of the development of more accurate muscle strength evaluation methods.”

Reliability has been reported in several low-tech tests that do not provide numerical quantification results. For example, The National Institute for Occupational Safety and Health (NIOSH) Low Back Atlas identified 19 tests with significant reliability (<0.74 Cohen’s kappa and >0.79 coefficient for interclass correlation coefficient [ICC]).63,64 Moffroid et al studied the ability of the 53 NIOSH tests to discriminate between LBP and nonpainful subjects.40 It was found that 23 of the 53 tests could not discriminate adequately between the two groups and when the seven strongest tests were grouped together, a sensitivity of 87% and specificity of 93% were obtained. Interestingly, the most important measurements were those that assessed passive mobility, dynamic mobility, strength, and symmetry. Harding et al, as well as others, reported that a group of low-tech tests were determined safe, reliable, and valid for assessment of physical dysfunction in chronic pain subjects.65 A series of simple trunk and lower extremity endurance tests have been shown to be reliable.66,67,68 A normative database segregated by age, gender, and vocation (blue collar vs. white collar) was determined for some of these tests on more than 500 individuals.66


A PPA, functional capacity evaluation (FCE), work capacity evaluation, or any type of assessment that evaluates physical function should not be done when the condition of the patient is unstable or when there is a probability for injury exacerbation.69 Some have advocated the use of a time frame such as a minimum of 2 weeks after injury or a pain level such as ≤6/10 be used as guidelines to determine when a PPA is appropriate, but there is little evidence to support these specific parameters. Rather, each case must be individually assessed to determine when it is “safe” to conduct a PPA. This is important as there are biologic risk factors that may include cardiopulmonary, musculoskeletal, and neuromuscular impairments, which can result in complaints such as exertion, dyspnea, fatigue, weakness, pain, and more during normal ADLs as well as during testing. In patients with a history of angina, for example, testing must stay below the threshold of inducing angina, which can vary greatly between subjects as well as within the same subject. In special cases such as this, careful monitoring by a cardiologist during testing in a facility capable of managing a severe reaction is appropriate and otherwise represents an absolute contraindication.

There are also well-published psychosocial and societal factors that enter into the decision-making process as to when a PPA is appropriate as well as what type of PPA.70,71 In a cross-sectional study of 170 work-related low back injured claimants undergoing FCEs (using the Isernhagen Work System FCE), the subjects were evaluated to determine the association between clinical and psychosocial factors on their performance.70 Using a battery of questionnaires and physical tests, FCE results were found to be influenced by physical factors, disability perception, and pain intensity. They concluded that FCEs “… should be considered behavioral tests influenced by multiple factors, including physical ability, beliefs, and perceptions.”

Hart et al report indications for functional testing include the following48:

  • Plateau of treatment progress

  • Discrepancy between subjective and objective findings

  • Difficulty in returning the patient to gainful employment

  • Vocational planning or medical-legal case settlement

Others recommend PPA or FCE for developing a treatment program; as a pre-, interim, and postrehabilitation assessment to modify a rehabilitation treatment plan; as well as to evaluate whether an injured worker can return to work and at what specific physical demand characteristic level (i.e., sedentary, light, medium, heavy, very heavy).71

The PPA assessment will allow objective confirmation of patient status to complement the patient’s subjective self-report of their symptoms. It also allows the health care provider to document patient progress over time. It will help to motivate the patient to pursue reactivation after injury. Prolonged passive care (e.g., hot packs, massage, ultrasound) directed at providing symptomatic relief may only achieve short-term results. When symptomatic not functional outcomes are the patient’s only goal, dependency on palliative treatments rather than reactivation advice can result.33

The “sports medicine” approach that measures functional impairment and uses reactivation advice and active exercise to rehabilitate injured tissues is recognized as the “standard of care” for soft tissue injuries.33,72,73,74 This active approach is better suited to alleviating pain, completing soft tissue healing, and preventing reoccurrences.

PPA Test Methods—What

A number of sophisticated high-tech measurement devices have been developed to enhance patient evaluation (MedX, Cybex, Iso B-200, IsoTrak, EMG). Research is driven by the use of such devices.1,14,15,16,17,18,19,21,39,49,75,76,77,78,79,80,81,82,83,84,85,86,87,88 However, evaluation of PPA can be performed with minimal if any special equipment or high cost. Though high-tech testing equipment is always an option, it is not necessary and in many instances may actually correlate less well with actual functional disability than simpler low-tech approaches.51,52 Simple, low-tech tests have evolved to a point at which many are reliable.52,66,67,89,90

The best tests are quantifiable and have established normative databases that allow comparison by gender, age, occupation, and history of back pain.65,66,67,68,91 Ideally, maximal performance (sincerity of effort) can be differentiated from feigned performance, although this is usually not possible especially with strength testing.92,93


Evaluation of mobility and flexibility is a common practice for most musculoskeletal medicine practitioners. ROM is usually restricted in acute situations and is one of the primary objective outcomes that can be tracked to show progress over time. However, in chronic patients, ROM testing may be of less value.

Sincerity of effort is an important consideration during ROM testing. In the Guides to the Evaluation of Permanent Impairment the validity of a patient’s effort is based on the repeatability of scores obtained over a series of measures.94 For instance, in the Guides each measure must be within 5 degrees of the average of at least three measures that are less than 50 degrees. If the average is more than 50 degrees, then each measure must be within 10% of that average. Thus, each measure must be within a certain standard deviation (SD) from the mean. Another measure of validity called the coefficient of variation (CV) has been shown to be even more useful. The CV is obtained by dividing the SD by the mean of the scores. The CV range for intraobserver goniometric measurements in the extremities has been shown to be between 4% and 10%.95,96,97,98 The CVs for lumbar motion are in the range of 6% to 14%,19 with patients having a greater range than asymptomatic individuals.99 CVs for the cervical spine range are reported to be up to 5%.54,92,100

Dvir has shown that in healthy individuals, sincerity of effort for cervical ROM may be judged from the CV54 Prior to the 6th edition (from 1971 to 2007), the AMA Guides offered a protocol for determining insincere effort in cervical and lumbar spine ROM assessment. When an unacceptable rate of false-positives occurred, the AMA guides considered using ROM for determining impairment as invalid.101,102 Noteworthy, the 2008 publication of the 6th edition of the AMA’s Guides to the Evaluation of Permanent Impairment no longer includes a spinal ROM method for rating permanent impairment because of many factors including insincere effort, pain affects, diurnal differences, and high variability on test-retest reliability.

Gilford showed that the circadian rhythm influenced flexibility, with muscle length or joint ROM measures more reliable in the afternoon.103,104 Several authors have reported a diurnal variation in lumbar spinal ROM.37,103 Similarly, Porter reported similar variance with orthopedic testing such as the SLR orthopedic test in which the SLR was found to be tighter in the morning.104

When performing ROM tests, it is important to perform each test as precisely as possible. For example, Ekstrand et al observed an improvement in the CV from 7.5 ± 2.9 to 1.9 ± -0.7 after using the tests for 2 months and subsequent refinement, paying attention to the details regarding105:

  • Standardized inclinometer placement and make sure the pendulum of the gravity type swings freely

  • Stiffening up the examination table (plywood with Velcro bands)

    Table 10.2 Mobility Tests

    1. Ankle dorsiflexion mobility/gastrocnemius and soleus length

    2. Knee flexion mobility/quadriceps length (Nachlas test)

    3. Hip flexion mobility/hamstring length (Straight leg raise test)

    4. Hip extension mobility (modified Thomas test/psoas-rectus femoris length)

    5. Hip rotation mobility (internal and external)

    6. Lumbar spine mobility

    7. Cervical spine mobility

  • Identify bony anatomical landmarks (mark on skin)

  • The examination bench height was standardized for each visit

The quantity of motion is perhaps of less importance than its quality.39,79,106,107 Velocity and symmetry of motion characteristics can be reliably identified with a simple and inexpensive triaxial goniometer system called a B Tracker (Isotechnologies, Hillsborough, NC).79 Marras’39 more sophisticated and expensive system utilizing the lumbar motion monitor to check three-dimensional kinematics of the lumbar spine during performance of industrial tasks has been shown to predict future industrial back injury claim. A novel technique for evaluating relative motion at C7-T1 and T1-T2 segments has found that a synchronous pattern of greater mobility at the higher segment is normal and that a nonsynchronous or inverse pattern with greater mobility at the lower segment is predictive of future neck-shoulder pain in a 2-year prospective follow-up study.99 This low-tech method utilizes skin markings and a flexible tape measure.

Table 10.2 shows the ROM tests that will be described in detail.

Ankle Dorsiflexion Mobility/Gastrocnemius Length Tightness of the gastrocsoleus has been shown to be correlated with increased knee injury risk in male college athletes.108 This test evaluates the length or tension of the gastrocnemius muscle and/or the articulation of the ankle joint (Fig. 10.1).

Patient Position

  • Patient stands upright, feet parallel, and knees straight


  • The electronic inclinometer is positioned above the lateral malleolus and “zeroed” in
    upright standing position, or a mechanical inclinometer is “zeroed” just below the tibial tuberosity.

    Figure 10.1 Ankle dorsiflexion mobility/gastrocnemius length.

  • The patient leans forward, placing the hands on a wall.

  • The tested leg is moved backward until a lunge position is assumed and the heel begins to lift from the floor; the front knee will be in a flexed position.

  • The subject pushes the heel down or slides slightly forward until the heel is flat on the floor; when maximum ankle dorsiflexion is achieved, the angle is recorded.


  • The normative data reveals 22.5 degrees

  • SD 0.7

  • Intra-assay CV 2.2%

  • Interassay CV 2.5%105,109,110,111

Soleus Length/Ankle Dorsiflexion Test This soleus length/ankle dorsiflexion test105,109,110,111 evaluates the length or tension of the soleus muscle and/or the articulation of the ankle joint (Fig. 10.2).

Patient Position

  • Patient stands upright, feet parallel, and knees straight


  • The knee is flexed and the ankle is dorsiflexed to a maximum angle maintaining heel-to-floor contact.

  • Alternatively, the patient may stand on the nontested leg and place the tested foot on a bench and the ankle is dorsiflexed to a maximum angle maintaining heel-to-bench contact.

  • The inclinometer position is the same as the first test (see Fig. 10.1).


  • The normative data reveals 24.9 degrees. (Note: please refer to the following section regarding updated procedure and normative data figures.)

  • SD 0.8

  • Intra-assay CV 2.2%

  • Interassay CV 2.6%105,109,110,111

Based on over 20 years of teaching and performing the ankle dorsiflexion mobility/gastrocnemius and soleus muscle length tests, frequent criticism has occurred concerning the seemingly low normative data of 22.5 and 24.9 degrees, respectively.105 A recent study compared three different methods of measuring the ankle dorsiflexion ROM by a novice evaluator
to determine the reliability of the methods as well as offered new normative data for each method.109,110 This study used a weight-bearing modified lunge test where the knee is flexed, thus eliminating the gastrocnemius and thereby assessing primarily the soleus muscle. The three methods included the use of a standard goniometer, a digital inclinometer versus a tape measure using the distance-to-wall method. Here, the barefooted subject faces a wall while maintaining balance by placing two fingers of each hand on the wall. The great toe is initially placed 10 cm away from the wall with the knee flexed and lined up with the second toe in a weight-bearing lunge position. The evaluator moves the testing foot either closer to or farther from the wall depending on when the heel rises up off the floor. The measurement is taken when the knee just touches the wall and heel simultaneously stays down on the ground at the maximum angle of ankle dorsiflexion.

Figure 10.2 Soleus length/ankle dorsiflexion test.

Twenty healthy subjects (mean ± SD: age 24 ± 3 years, height 173.2 ± 8.1 cm, mass = 72.6 ± 15.2 kg, 13 males/7 females) were each assessed three times per side with a 10-minute rest between the first and second set of measures. The within-session intrarater reliability (ICC2,3) estimates for each method are as follows: tape measure (right 0.98, left 0.99), digital inclinometer (right 0.96, left 0.97), and goniometer (right 0.85, left 0.96). The SEM (standard error of measurement) and MDC (minimal detectable change) are as follows: tape measure SEM (range 0.4-0.6 cm) and MDC (1.1-1.5 cm); inclinometer SEM (range 1.3-1.4 degrees) and MDC (3.7-3.8 degrees); and goniometer SEM (1.8-2.8 degrees) and MDC (5.0-7.7 degrees). This study demonstrates that a novice rater can reliably measure weight-bearing ankle dorsiflexion ROM using all three methods. The distance-to-wall method using a tape measure and the inclinometer methods resulted in the highest reliability coefficients (ICC2,3 = 0.96-0.99) and lowest SEM compared to the use of a goniometer (ICC2,3 = 0.85-0.96). The normative data derived by each method are as follows:

(From Trial 1) (No significant difference between Trial 1 and 2)

Tape Measure: 9.5 ± 3.1 cm (0.89 right, 0.27 left)

Digital Inclinometer: 38.8 ± 5.2 degrees (0.07 right, 0.22 left)

Goniometer: 43.2 ± 5.8 degrees (0.56 right, 0.07 left)

A simplified version of the weight-bearing ankle lunge test by placing the testing foot/ankle on a 30 to 45 cm high box (they used a 30.5 cm box) and lunging or leaning forward while maintaining a straight/neutral foot (parallel to the edge of the box) with heel firmly planted was reported as valid and reliable using 24 males and 26 females averaging approximately 20 years of age.110 This method is reportedly quick (˜30 seconds) compared to the standard tape measure approach (˜3 minutes) and offers another way of assessing ankle dorsiflexion/soleus muscle length. Here is the normative data derived from this method:

Inclinometer: 48.1 ± 6.0 degrees (SEM: 1.3; ICC2k: 0.95; MDC95: 3.8 degrees)

The authors state that for subjects with limited knee flexion, a shorter box was preferred and recommended a 10 to 15 cm height box. The inclinometer used in their study included a telescoping arm that is to be placed parallel to a line that bisects the lower leg, which reportedly eliminates the need for referencing a specific bony landmark. The authors found no significant difference between the left and right sides (1.9 degrees; 90% CI from -2.1 to 3.8) or in the test-retest trials (the mean of two maximum efforts performed over three trials within 2 weeks) and therefore, they offer one set of normative data utilizing the mean values from the trials. They report that an observed change larger than 3.8 degrees from baseline scores postrehab indicates a real change in ankle dorsiflexion.

An instrument designed to measure the ankle dorsiflexion ROM was compared to the tape measurement method described by Konor et al.110,111 It is analogous to the modified lunge test distance-towall method and was similarly found to be a valid and reliable method but requires the use of a special device (Leg Motion system). The normative data derived by this group varied slightly from those of Konor et al, as they reported 11.6 cm ± 4.0 (left), and 11.8 cm ± 4.2 (right) when using the tape measure distance-to-wall method (26 healthy male students aged 22 ± 2.1 years).

Given the low sensitivity of the Ekstrand et al105 normative data and the review of the current literature report earlier, we feel the Cejudo et al110 simplified version is most practical with similar reliability but greater sensitivity using their methods and normative data of 48.1 ± 6.0 degrees (MDC 95% of 3.8 degrees).

Knee Flexion Mobility/Quadriceps Length (Nachlas Test) The knee flexion mobility/quadriceps length (Nachlas test)105,109,110,111 evaluates the length or
tension of the quadriceps femoris muscle and/or the articulation of the knee joint (Fig. 10.3).

Figure 10.3 Knee flexion mobility/quadriceps length (Nachlas test).

Patient Position

  • The patient is prone on table.

  • The inclinometer is positioned at the posterior aspect of the mid-calf and zeroed (alternate position is on anterior shin after being zeroed to bottom of table or desk)

  • The pelvis is stabilized.


  • Patient’s knee is passively flexed (approximate heel to buttock).

  • The angle is measured at point just before lumbar spine begins to extend or hip raises up.


  • The normal angle equals 147.9 degrees

  • SD of 1.6

  • Intra-assay CV (%) 0.5%

  • Interassay CV (%) 1.1105,109,110,111

Hip Flexion Mobility/Hamstring Length—SLR Test The hip flexion mobility/hamstring length—SLR105,109,110,111,112,113 evaluates the length or tension of the hamstring muscle and/or the articulation of the hip joint (Fig. 10.4).

Patient Position

  • The patient lies supine on a firm table and the inclinometer is placed just superior to the patellae (or alternatively on mid-tibia or strapped to lower leg with Velcro) and then zeroed.


  • The patient’s calf is placed in the crook of the doctor’s elbow or rests in the doctor’s hand.

  • The patient’s hip is flexed without permitting any knee flexion to occur.

  • The angle is recorded just before pelvic movement or knee flexion.


  • Normal ROM is 70 to 90 degrees (use 80 degrees as the mean for patient comparison).

Hip Extension Mobility/Psoas-Rectus Femoris Length (Modified Thomas Test) This tests tightness in the iliopsoas,105,109,110,111,113 which has been shown to be correlated with increased knee injury risk in male college athletes.108 Reduced ROM in hip extension has been reported frequently in LBP subjects.43,113,114 Preliminary data from McGill suggest that decreased hip extension mobility may be predictive of disabling LBP.115 Van Dillon reported that chronic LBP subjects had less passive hip extension ROM than asymptomatic subjects.43 Studies in adolescents have documented that future episodes of LBP are correlated with decreased hip extension ROM.43,114 Some controversy exists, however, because Nadler reported that hypermobility in the lower extremity was correlated with future LBP in college athletes.116,117

The modified Thomas test evaluates the ROM of the hip and/or the length or tension of the hip flexor muscle group (iliopsoas muscle) (Fig. 10.5).

Patient Position

  • The patient perches at the end of bench in a manner where the ischial tuberosities are supported on the end of the table’s edge.

    Figure 10.4 Hip flexion mobility/hamstring length. Straight leg raise test.

    Figure 10.5 Hip extension mobility/psoas-rectus femoris length (modified Thomas test).

  • The knee and hip are flexed and the knee is drawn up tight to the chest to eliminate lumbar lordosis and the patient is lowered to a supine position maintaining the knee-to-chest position.


  • The inclinometer is zeroed to the horizontal of the table top.

  • The leg being tested is allowed to extend toward the floor and hang freely fully relaxed.

  • The knee should be brought to the chest to fully remove the slack and flatten the lumbar lordosis firmly to the table.

  • Place the inclinometer on the anterior thigh just below the anterior superior iliac spine (ASIS). Record the angle when tested leg is fully relaxed, hip extended, and the lumbar lordosis is removed.


  • The normative data is 6.5 degrees

  • SD 1.1

  • Intra-assay CV 0.7%

  • Interassay CV 1.2%113

Alternatively, Ekstrand published the following method.105,109,110,111

Patient Position

  • Patient lies supine with the knees straight on the bench


  • Place the inclinometer 5 cm above the patella on the lateral thigh and set to zero.

  • The leg being tested is passively flexed to 90 degrees using the initial inclinometer 0 degrees reading and the inclinometer reset to zero.

  • The rest of the test is the same as the last three steps described previously.


Apr 17, 2020 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Quantification of Physical Performance Ability

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