January / February 2000 Table of Contents
In this Article
Physical Effort and Symptom Magnification
By Min Trevor Kyi
Work Capacity Evaluation (WCE) is used to determine an individual's physical abilities, limitations, and readiness to return to work. In the early 1980s, Dr. Leonard Matheson defined Work Capacity Evaluation as "a systematic process of measuring and developing an individual's capacity to dependably sustain performance in response to broadly defined work demands" (Matheson, 1986). As occupational therapists we are aware of the influence that symptom magnification can have on the client's perception of his or her job readiness. Therefore, in order to thoroughly assess an individual's true work capacity, it is important to separate objective findings gathered during physical effort testing, with more subjective findings gathered during symptom magnification testing.
History of WCE
In current practice, interchangeable terms for Work Capacity Evaluation
include Functional Capacity Evaluation (FCE) and Physical Capacity Evaluation
(PCE). Certification in this field began in the early 1980s, initiated
by Dr. Len Matheson at the Employment Rehabilitation Institute of California
(ERIC). Training and Certification programs continue to this day, with
Len's brother Roy taking over responsibility for the certification program
in 1990. While RMA training is certainly one major program in the field
of FCE, a variety of other evaluation systems are also available. Other
major systems include: Blankenship, Isernhagen and Key.
Physical Effort and Symptom Magnification
Two issues pivotal to the usefulness of the Work Capacity Evaluation are
Physical Effort and Symptom Magnification. Here I will seek to clearly
define for the reader that while both areas are integral parts of the
Work Capacity Evaluation, they differ considerably in nature and purpose.
As such, they should be evaluated using different measures, with findings
presented separately.
Definitions
Physical Effort refers to an individual's tendency to provide high levels
of physical exertion during encountered testing procedures. This type
of testing is best evaluated via a multi-faceted approach, ideally implementing
a combination of: isometric, behavioural and/or cardiovascular measures
to help gauge a client's level of effort. Results of physical effort testing
are not intended to imply motivation or intent (Kyi, Enright, Reynolds,
& Lynch, 1999).
Symptom Magnification, in contrast, refers to the conscious or sub-conscious tendency of an individual to under-rate his or her abilities and/or over-state his or her limitations. Symptom magnification is measured through assessment of observed functional performance, as compared to a client's subjective reports of the limitations caused by his or her symptoms. It does not imply intent. This concept is based upon Dr. Leonard Matheson's original term of symptom magnification syndrome (Matheson, 1990, 1991). While subjective reports of persons exhibiting symptom magnification should certainly not be ignored, they should be considered with caution. In such instances, significantly more weight should be placed upon objective findings and test results versus a person's subjective reports or estimates of ability (Kyi, Enright, Reynolds, & Lynch, 1999).
Evaluating physical effort
Physical effort testing is a key component of WCE. An individual's physical
response to encountered testing is crucial to the outcome of his or her
evaluation results. Evaluating a client's true physical capacity requires
high levels of effort by the client. If the client being evaluated does
not provide full effort during testing, it becomes difficult, if not impossible,
to accurately gauge the full extent of his or her work abilities and/or
subsequent physical limitations. In such instances, the evaluator has
simply no way of knowing the client's actual maximums, as he or she did
not try his or her best during testing. The evaluator is thus left in
the position of clearly and objectively documenting the client's minimum
levels of function.
The term validity is often used in the field of vocational rehabilitation as an umbrella term to evaluate a client's level of effort, and subsequently the end value of attained test results. For results to be truly valid at representing a client's maximal abilities, it is critical that the client apply full effort when tested. Different systems apply different methods of evaluating a client's level of effort. As such, they rely on varying techniques to determine the validity of test results.
Certain evaluators and evaluation systems make use of a Validity Profile, wherein a client's consistency is evaluated via a pass/fail score on a number of validity check items (typically 15 to 25). Such items may include the following tests:
- Jamar Coefficient of Variation Testing (Matheson, 1988);
- Jamar Rapid Exchange Grip Testing (Joughin, Gulati,
- acKinnon, McCabe, Murray, Griffiths & Richards, 1993), (Hildreth & Lister, 1989);
- Jamar Bell Curve Analysis (Stokes, 1983);
- Non-Organic Sign Testing (Waddel, McCulloch, Kunnel & Venner, 1980), (Novy, Collins, Nelson, Thomas, Wigins, Martinez, Irving & Waddell, 1998), (Waddell, Birchner, Finlayson & Main, 1984);
- Placebo Testing (Kyi, Enright, Reynolds, & Lynch, 1999), (Blankenship, 1999), (Waddel, McCulloch, Kunnel & Venner, 1980), (Novy, Collins, Nelson, Thomas, Wigins, Martinez, Irving & Waddell, 1998), (Waddell, Birchner, Finlayson & Main, 1984); and/or
- Consistency of Pain Reports (Kyi, Enright, Reynolds, & Lynch, 1999).
Each item is given one point on the Validity Profile scale. While pass rates may vary from clinic to clinic, a 70% pass rate is generally required to deem test results as valid (Blankenship, 1999).
Flaws in Validity Profiles
Such a method of evaluating effort presents with two primary flaws. First,
validity profiles assume all effort tests have equal weighting. This is
erroneous, as some tests in the profile may be well researched, published,
and peer reviewed, while others are often extremely simple or home-made
methods used to help gauge a client's level of cooperation with testing
protocols. Validity profiles falsely provide equal weighting to each test
result.
The second flaw in such validity profiles is the combination of physical effort and symptom magnification tests in the same scoring scheme. As discussed earlier, effort tests relate directly to whether or not a tested client tried his or her best during testing. In contrast, symptom magnification tests are designed to evaluate whether or not a client's subjective reports are reliable, helping with eventual decisions concerning the client's case.
Historically, tests such as the Spinal Function Sort (Matheson, L., Matheson, M. & Grant, 1993), (Gibson & Strong, 1996), Waddell Testing (Waddel, McCulloch, Kunnel & Venner, 1980), (Novy, Collins, Nelson, Thomas, Wigins, Martinez, Irving & Waddell, 1998), (Waddell, Birchner, Finlayson & Main, 1984) and/or Placebo Testing are used to help an evaluator better measure the reliability of a client's subjective reports of pain and disability. Functionally defined pain scales (Kyi, Enright, Reynolds, & Lynch, 1999) are also used in this regard, to help gauge whether or not a client tends to under-rate or over-rate his or her pain and limitations.
Summary
The bottom line is that some clients who magnify their symptoms and subsequent
limitations may still provide full physical effort. The corollary is that
some clients who do not complain of non-anatomical pains and subjectively
rate their abilities high, may not provide full physical effort when tested.
An example: Peter
Peter is a 44-year-old auto mechanic who has been absent from the work
force for over three years. He perceives himself as highly disabled, and
strongly doubts his physical abilities. He is inherently afraid that his
evaluator will miss some of his limitations, and feels he must stress
that he does truly have pain. When Peter comes in for clinic testing,
he rates his pains far higher than expected; for example, 9/10+ where
10+ is emergency hospitalization, despite moving fluidly and conversing
freely, during the testing. In addition, he fails various placebo tests;
for example, when asked if shifting his knee cap causes increased low
back pain, he will say "yes," though it should not increase
his pain. When rating his perceived strength to lift and carry items,
he guesses very low; for example, 5-10 pounds.
However upon actual testing, Peter is a client who provides high levels of effort. It remains his nature to try hard when asked to perform testing activities. As such, his heart rate readings suggest high levels of effort. His isometric strength scores suggest high levels of consistency and subsequently good effort. Throughout his testing day, he remains competitive in his approach to encountered testing, attempting to start timed tests early, ask for extra practice time, and recruit additional musculature, each approach helping maximize his performance. As such, Peter actually does quite well on his physical testing, performing far better than he subjectively anticipated.
In Peter's case, appropriately completed test findings would identify a client who partook in his testing with high levels of physical effort. As such, resultant data would be well representative of his actual abilities and limitations. Further testing however would show that Peter also presents with a significant degree of symptom magnification. He tends to complain of atypical (non-anatomical) pains at times. He significantly under-rates what he can actually do. His subjective reports of pain are higher than one would expect from observing his distraction-based movements, and are extinguishable upon distraction. As such, resultant symptom magnification findings suggest that individuals involved in Peter's case should be cautious in relying on his subjective reports as fully accurate or credible. More weight should be placed upon objective findings and test results than upon Peter's subjective reports of ability or limitation.
Both physical effort testing and symptom magnification testing remain crucial components of Work Capacity Evaluation. While each has high value, they are not the same. As such, it is important that they be evaluated by different measures, with resultant findings presented clearly and separately.
We would be very interested in having other therapists write in to discuss individual approaches to addressing such crucial aspects of functional testing.
Please participate in the online
discussion group or submit your comments or ideas to Mary Clark Green,
Managing Editor c/o CAOT, CTTC Suite 3400, 1125 Colonel By Drive, Ottawa,
ON K1S 5R1 or e-mail: wpc@istar.ca.
Min Trevor Kyi, B.Sc. (O.T.), Reg. O.T. (BC) is a certified Work
Capacity Evaluator (Advanced), with a graduate diploma from the University
of Florida in Functional Capacity Evaluation. He is a clinical faculty
member with the University of British Columbia, teaching 4th year classes
in vocational rehabilitation and ergonomics. Min is also on faculty with
the RMA Certification Program out of Keene New Hampshire. He is a qualified
expert witness to the Supreme Court of BC in the fields of occupational
therapy, Work Capacity Evaluation, brain injury and cost of future care.
Min is an occupational therapy consultant at Progressive Rehab. Inc.,
Suite 108, 4240 Manor Road, Burnaby, B.C. V5G 3X5; e-mail: mkyi@home.com.
The current Matheson training program is entitled RMA, for Roy Matheson and Associates. This system trains health care practitioners in the field of Work Capacity Evaluation.
References
Blankenship, K. (1999). Blankenship Industrial Residency Manual and Revisions. Macon, GAÚ The Blankenship System.
Gibson, L. & Strong, J. (1996). The reliability and validity of a measure of perceived functional capacity for work in chronic back pain. Journal of Occupational Rehabilitation, 6, 159-175.
Hildreth, D.H. & Lister, G.D. (1989). Detection of submaximal effort by use of the Rapid Exchange Grip. Journal of Hand Surgery, 14A, 742-745
Joughin, K. Gulati, P., Mackinnon, E., McCabe, S., Murray, J.F. Griffiths, S., & Richards, R. (1992). An Evaluation of Rapid Exchange and Simultaneous Grip Tests. Journal of Hand Surgery, 245-252.
Kyi, M.T., Enright, W., Reynolds, J., & Lynch, L. (1999). RMA: Certified Work Capacity Evaluator - Training Manual and Residency. Keene, New Hampshire: Roy Matheson & Associates
Matheson, L.N. (1988). How do you know he tried his best? Journal of Industrial Rehabilitation Quarterly, 1, 10-12.
Matheson, L.N. (1990). Symptom Magnification Syndrome: A modern tragedy and its treatment - part one: Description and definition. Industrial Rehabilitation Quarterly, 3, 1-23.
Matheson, L.N. (1991). Symptom Magnification Syndrome, structured interview: Rationale and procedure. Journal of Occupational Rehabilitation, 4, 1-17.
Matheson, L.N., Matheson, M.L. & Grant, J. (1993). Development of a measure of perceived functional ability. Journal of Occupational Rehabilitation, 3, 15-30.
Novy, D.M., Collins, H.S., Nelson, D.V., Thomas, A.G., Wiggins, M., Martinez, A. & Irving, G. (1998). Waddell Signs: Distributional properties and correlates. Archives of Physical Medicine and Rehabilitation, 5, 820-822.
Ransford, A.O., Cairns, D. & Mooney, V. (1976). The pain drawing as an aid to the psychological evaluation of patients with low back pain. Spine 1, 127-134.
Stokes, H.M. (1983). The seriously uninjured hand- weakness of grip. Journal of Occupational Medicine, 9, 683-684.
Waddell, G., Birchner, M., Finlayson, D., & Main, C.J. (1994). Symptoms and signs: Physical illness or illness behaviour? British Medical Journal, 289, 739-741.
Waddell, G., McCulloch, J.A., Kummel, E. & Venner, R.M. (1980). Non-organic physical signs in low-back pain. Spine, 5, 117-125.
January / February 2000 Table of Contents
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