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9 Articles in Volume 10, Issue #4
Chaos (Nonlinear Dynamics) and Migraine
Enhancement of Nerve Regeneration by Therapeutic Laser
Functional Capacity Evaluation (FCE)
Making Practical Sense of Cytochrome P450
Non-pharmacologic Treatment of Shingles
Pain, Neurotechnology, and the Treatment-enhancement Debate
The New Age of Prolotherapy
Treating Myofacial and Other Idiopathic Head and Neck Pain
Treatment of Painful Cutaneous Wounds

Functional Capacity Evaluation (FCE)

While not yet precise enough as a predictive tool, FCE can be combined with other sources of information such as medical, rehabilitative and diagnostic data to help resolve issues of compensability, disability and employability.

The functional capacity evaluation (FCE) has evolved in many ways since its inception in the 1980s when the work capacity test was becoming the normative test to evaluate disability and return to work status.1 In our quest to be able to identify applicants who might be at higher risk for lower spine injuries once employed, we began utilizing various forms of pre-employment testing including radiographic screening.2 As we all know, this specific practice was short-lived and pre-employment screening as an evaluation tool has subsequently been abolished with the advent of research showing a poor correlation between radiographic findings and risk of future injury.3 Radiologic abnormalities in the musculoskeletal system have not been demonstrated to have any significant predictive capabilities for future risk of injury and, along with legislative changes—most notably the American with Disabilities Act (ADA) and it’s antecedents—have led to the demise of pre-employment screening efforts.4

The most politically correct post-ADA terminology for workplace testing is pre-placement screening. Today, the applicant is hired and then tested (in that order) and a decision made as to whether they can safely and effectively perform the job. The “fit for duty” assessment is performed after the hiring, and not before, as was the case in the past. For the remaining sections of this report, the terms FCE, physical capacity evaluation (PCE), and work capacity evaluation (WCE) will be used to denote separate but distinct (although interrelated) testing formats. The PCE is a physical capacity evaluation that identifies basic human motion parameters, both quantitatively and qualitatively—such as muscle strength, endurance, flexibility, stamina, power, balance, coordination and proprioception. It is important to distinguish these most basic parameters since they are the foundation of the next level test—the FCE, or functional capacity evaluation. This test examines functional limitations that are defined by more complex multi-joint movements that require neuromuscular synergy to form integrated and purposeful patterns aimed at task completions and could be anything from climbing stairs to lifting a box or sweeping the floor. Within the context of an occupational setting, the term WCE or work capacity evaluation implies a work related FCE since the test evaluates the person’s ability to perform work-related functional tasks, as opposed to home or recreation/social activities of daily living.

Selecting The Appropriate Test

In our practice, we find that different groups request different tests depending on their needs. For example, attorneys want both impairment data (PCE) and functional data (FCE) in no fault cases, but FCE and WCE data in workman’s compensation litigation. In social security determinations, the data requested is primarily FCE-oriented. Our case managers who deal with occupational injury/disease need specific WCE data that is an occupationally-oriented FCE. I have made the distinction between a generic versus specific FCE because one of the real problem areas with FCEs has been poor test selection—i.e., using a generic FCE when the situation warrants a specific FCE based on essential job demands—gathered using a valid job description and/or a job site analysis.

When a general (generic) versus a specific FCE is used to make a return to work determination, the end result can be suboptimal. Some recent litigation, James versus Goodyear Tire and Rubber Co., has shed some light on how FCEs are viewed in a medico-legal milieu.5 In this case, the company recommended an FCE to determine where to safely put a certain employee who was suffering from a progressive disease. Although the worker retired—never having been FCE-tested—he still sued claiming that the FCE would have been a discriminatory action. The court ruled against him stating that the evaluation was motivated by reasonable safety concerns and therefore not an adverse action. If the FCE were to have been carried out, the court stated it would have assessed the relevance or correlation between the test and actual job. It becomes clear that the more specific the test, the greater the relevance for the worker and employer. In another case, Indergard versus Georgia Pacific, the worker was not allowed to return to work based on results gathered from PCE-FCE test(s) and went on to file a discrimination suit.6 There are a number of issues that arise from this case including sharing information with the employer, who performs the actual test and, not least important, did the test criteria or test items on the PCE-FCE match the actual job requirements—i.e., specificity.

FCEs Current Scope

The conundrum of identifying persons most at risk for injury while working, or whether a person is ready and/or capable of returning to work at all, persists even today. The FCE has become, arguably, more functional and less reliant on expensive technology—e.g., utilizing boxes for lifting/carrying tasks and sleds for push/pull tasks. Only relatively few facilities are able to offer the more sophisticated dynamometric testing for PCE data, such as might have been the norm in the past. The lingering questions remain, however, as to whether the FCE is an accurate representation of a person’s ability to perform physical work. Are the results of the FCE reproducible (consistent)? Does it measure what it purports to measure (validity)? Is the FCE sensitive enough to measuring functionally-important changes that might translate into a higher probability of a patient returning to work? And finally, are the results of the FCE-WCE predictive of the primary outcome of interest, namely, the return to work? The results of these assessments have implications for employment, compensability determinations, further medical/rehabilitative efforts, disability evaluations, and indemnity/cash benefits.7

The number of FCE vendors has risen noticeably over the last 15 years, and this form of testing is often used in combination with work conditioning and work hardening (job simulation) programs aimed at returning injured workers back to their respective workplaces. The various vendors have their own proprietary systems that they sell to providers—mostly physical and occupational therapists who are those ultimately performing the testing. We have no idea how the various FCE tests sold relate to each other. In other words, are the test results from one system transferrable to another? Is there a gold standard FCE out there? If there was, we could begin to compare FCE systems with the gold standard and derive an estimate of concurrent validity but, as it stands, we do not. Important to note, however, is that the major FCE vendors do use a standardized set of tasks, with each device having their own internal validity. Variability in test administration (test format, instructions provided, timing, etc.) is minimized with training and experience. As well, when evaluating an FCE, it might be impractical to expect tight test-retest reliability measures such as one would expect to see when performing repeated measures on a machine or instrument. The FCE is made up of a series of tests that contribute to the total disability rating, with each test measuring a potentially different dimension of human movement and capability.

“The results of these assessments have implications for employment, compensability determinations, further medical/ rehabilitative efforts, disability evaluations, and indemnity/cash benefits.7

How much precision do we expect from an FCE test? After all, we are trying to get at a functional rating score made up of measures that tend to vary from day to day and based on a constellation of variables—such as co-morbidities, aging, injury, weather, sleep level, motivation, stress etc. We often try and characterize sincerity levels when performing the FCE test items since the psych-physical connection will ultimately determine the actual scores on each test item. A number of possible methods have been proposed to get an estimate of patient sincerity levels when performing the FCE—including using the coefficient of variation (ratio of the standard deviation of a set of scores to its mean, expressed as a percentage). The validity of using the CV statistic, in isolation, for measuring sincerity of effort has been challenged however.8,9 The consensus appears to be that the CV statistic is a valuable component in the determination of sincerity of effort but should be used in conjunction with other protocol measures—creating what Matheson refers to as a reliability profile.10

In many cases, the FCE and WCE testing is performed prior to commencing a work recovery program to identify functional deficits and, at the end of a work program, to determine if goals were met and return to work is possible. This is the case where there is an injured worker who has been through formal physical and/or occupational therapy but is not ready to return to work. It is important to note that physical therapy is designed to focus on restoring normal range of motion, strength, muscle endurance etc. It is not unusual that a person, who has restored strength and mobility in a joint, still is not ready to return to work. There are other reasons that can act as barriers to the return to work process including fear, anxiety, lack of confidence, kinesiophobia, anger, poor motivation, and the list goes on. The use of a bio-psycho-social approach in the return to work process is recommended by many experts today.

Other common uses of the FCE are as integral components of a disability assessment evaluation (SSD) or any kind of medical disability or independent medical exam (IME). There are many different versions of the FCE but most utilize a standardized set of tests for both material handling and non-material handling activities. There has been a greater focus on customizing the FCE to the individual worker needs based on the ADA requirement that valid testing should be job specific and concentrate on a comparison between the person’s capacity and the actual job demand(s).11 The fundamental weakness in how FCEs are carried out today lies in the assumptions that test administrators make when scoring the test. These assumptions take the form of extrapolations such as: if a person is able to lift a 50 lb weight one time then they should be able to lift a 25 lb weight five times. Often times, these assertions are not tested but merely assumed. Another example might be that a test administrator in making the assumption that, because an applicant for a material handling position can exert a lift force of 100 lb one time using static dynamometry or load cell device, this equates to being able to perform repeated sub-maximal dynamic lifts of 30 lbs such as might be required by a person who carries car batteries from a conveyor to a rack most of the day. Extrapolation from maximal ability to perform occasional lifting to expected ability to perform frequent lifting on the job is a common practice that lacks scientific basis. We know that low frequency high load lifting taxes the musculoskeletal system, whereas high lifting frequency involving low loads taxes the cardiopulmonary system.12 It is incumbent on the test administrator to customize the FCE and WCE testing to the individual. Generic testing of various force limits imposed by lift, carrying, pushing/pulling capacities has a very limited value and, unless a generic or non specific FCE has been requested, should be avoided.13

Measurement Properties of the FCE

Dusik et al14 conducted a comprehensive investigation of return to work (RTW) criterion validity. They compared FCE results using a standardized testing protocol for job simulation and then followed RTW outcomes of a functional rehabilitation program post discharge. The FCE appeared to be less accurate than the job simulation and consistently underestimated actual ability to do the job.14 There are several sources of significant error or variation in FCEs that have been identified over the years—including poor characterization of job demands and inaccurate assessment of the person’s capability in relation to defined tasks. The latter is usually due to extrapolation of job duties from the dictionary of occupational titles (DOT) manual, or U.S. Department of Labor O*NET database, instead of actually performing an on-site job analysis. These databases were designed to classify jobs, not to analyze people and their performance. Furthermore, employer and employee job description versions can be inaccurate since workers often develop their own manner of performing a task that deviates from that described on a job description form. As well, workers operating under a certain job title often perform the work in very different ways including variation in loads handled and the frequency of load handling.

Innes and Straker concluded that an FCE performed without a formal job evaluation has a high likelihood of suffering from poor internal validity.15 Non-specific measures that do not relate to work tasks have a high probability of being irrelevant. In one study that looked at pre-placement decisions based on general, non work-related tests of aerobic capacity using normative data found that it can lead to discrimination against those persons who have higher body mass indices, despite their being able to perform the job.16 Isokinetic testing using dynamometry as part of an PCE has been criticized for not being functional enough and lacking the ability to test for agility or coordination—both inherent in healthy movement.17 The use of isokinetic measures has more recently being shown to have greater predictive power than the FCE when it comes to work injury prevention. Gilliam et al18 found that a shoulder-knee isokinetic test, performed as a PCE, to be significantly more effective as a predictor of whether or not a new hire will become injured during work-related activity in a food distribution services company. These investigators examined not only force-generating capacity of muscles but also considered upper to lower body strength and endurance ratios and then applied proprietary formulae to estimate risk of future injury.

Other important sources of variation in the FCE and WCE are those elements—such as vibration, heat, cold, worker isolation, stress, time pressure, etc.—that are difficult to reproduce and integrate into a test session. Moreover, these factors may impact return to work scenarios and are difficult to assess their individual impact on the RTW decision.19

Some have argued that observed changes in body mechanics could provide some insight into identification of maximal acceptable loads. This method is referred to as the kinesio-physical approach. Research does not support this method since both over- and underestimation of actual ability can occur.20 This observational approach relies on the skill and experience of the test administrator.

Responsiveness and Reliability of the FCE

There is some evidence suggesting that changes in FCE performance over time can represent meaningful improvement in function.21 It is difficult to know how much change is meaningful and sufficient for RTW. Since reliability of many FCE tests have not been properly documented, it is difficult to know whether changes in an FCE score represent actual or true change versus measurement error.22 A responsive measurement tool is one that can detect small but significant increments of change when applied repeatedly. There are two problems when applying this concept to the FCE. The first is practicality since insurance carriers typically will not pay for repeated FCEs since repeating the FCE is not necessarily going to improve an outcome. The second is that we have not been able to identify how much change is required between two successive FCE tests for the difference to be significant or impactful to a RTW outcome.

The FCE is a multi-item assessment tool made up of different tests including various lift tests. Lifting capacity is second only to hand-held dynamometry when it comes to being the most studied test item. Strength testing protocols were developed shortly after Chaffin et al published their seminal work on maximal isometric strength and demonstrated that those persons who had a lower strength capability relative to their job requirement had a three-fold probability of sustaining an injury as compared to the higher strength to job demand group.23 The market was quick to respond to this revelation and led to the development of the first generation FCE testing devices which spanned the entire range of possible muscle actions including isometric, isotonic, isokinetic, isodynamic, and isoinertial. The original strength research was performed using static testing (isometric action). These other forms of muscle testing were untested variants and all were dynamic in nature.

Lift test reliability has been studied and documented to be very high by Alpert et al. They studied both isokinetic and isoinertial modes and found them both to be highly reproducible (test-retest reliability), with r=.90, and r=.82 being reported respectively.24

Impairment/Disability Testing

The ability to capture an accurate profile of a person’s functional capability is not an easy task and fraught with challenges. There are so many variables in the domains of biology, psychology, sociology, and the environment that interact and eventually impact and play a role in the final assessment. To make matters more complicated, these variables are dynamic and ever-changing and helps explain the elusiveness of research support that is usually the underpinning of a test that has been in use for the last 25 years. There are, however, guidelines that should be adhered to when conducting an FCE based on the scientific, regulatory, rehabilitative and legal perspectives and experiences to date. The FCE protocol chosen should be one that has demonstrated reliability and responsiveness. In a RTW scenario, the protocol must be based on a valid job description but, preferably, a recent job site analysis. From the job site analysis, those essential job demands are identified and incorporated into the FCE as test items. If this procedure is followed, there is an increased probability that the FCE used will be a valid one and makes the test more predictive of successful return to work. Test reliability can be improved by ensuring that the test administrator performs consistent with instructions and understands the test format. Experience and training as an observer is important to consistency of the testing. Although the FCE and WCE looks at specific functional tasks and identifies maximal and safe load limits, it is the PCE that might have the better predictive power when attempting to identify those most likely to be injured performing a certain job category such as in a pre-placement screening. General FCEs should be avoided whenever possible in return to work situations since they do not possess validity due to the low relevance between test items and actual work performed.

Impairment testing is arguably a less difficult process compared to disability testing since the disability state is a function of the culmination of the entire range of bio-psycho-social and environmental influences. We have better testing tools with greater objectivity and precision for impairment testing, including computerized dynamometry that minimizes tester interaction to some degree. Some investigators argue that mechanical methods of strength measurement (PCE) can yield comparable information about a person’s ability to perform mechanical work.25 Disability can be viewed as impairment, with all the functional overlay previously discussed added to it. Given impairment and enough time, the different bio-psycho-social factors begin to inter-digitate and blend into each other making the process of teasing out actual impairment difficult. At this time we understand that in return to work cases the more time a person is away from work, the less the likelihood of an uncomplicated RTW scenario.

Conclusion

Comprehensive evaluations of function are highly sought out procedures because of the potentially useful information they yield. We rely on these test results to make life-changing decisions such as eligibility for disability, disability status for legal claims, return to work decisions, work related pre-placement decisions, injury prediction modeling, and medical and rehabilitation determinations, to mention a few. We have identified various sources of error inherent in this type of testing, as well as strategies to minimize the variance component. The PCE and FCE data can be very useful when the correct test (specific vs. general) is selected and executed by a trained professional. The combination of PCE and FCE data is optimal and can be used to provide an even broader scope of data that includes isolated muscle strength, endurance, and work parameters combined with more integrated functional and task-oriented results to provide a more global profile of risk (injury prediction) and current functional status to help guide return to work or general status determinations. The merging of PCE and FCE data with current IME testing would seem to be a practical way to enhance the IME for all stakeholders involved. This would provide a significantly more robust medical report that captures a more accurate, realistic and comprehensive data profile.

In occupational settings, The 1978 Uniform Guidelines on Employee Selection Procedures (29 Code of Federal regulations, Chapter XIV, Part 1607) provides a framework for the proper use of test procedures. More recently, the Americans with Disabilities Act (ADA) addresses similar concerns for disabled persons but applies also in cases where the employer wrongly perceives disability in a worker. In the case of pre-placement screening/testing, both regulations need to be considered when selecting a certain test or measure such as an FCE/WCE or PCE. The important message regarding the FCE is that it can be combined with other sources of information such as the medical, rehabilitative and diagnostic data to help resolve issues of compensability, disability and employability. However, more research is required if the goal is to ultimately having the FCE become a tool for predictability.

Last updated on: March 18, 2013
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