A conceptual framework of functional capacity evaluation for occupational therapy in work rehabilitation

Functional capacity evaluation (FCE) is commonly used in work rehabilitation to assess the capacity of the injured worker for return to work. Occupational therapists are major providers of FCE, especially in Australia. Despite a history of involvement in the functional assessment of clients for work, occupational therapy has few theoretical models for work assessment in general, and for FCE in particular. This may account for some of the confusion that exists about the conceptual basis of FCE in occupational therapy practice. This paper presents a framework for FCE that parallels occupational therapy's occupational performance model and the World Health Organisation's International Classification of Functioning, Disability and Health. The framework is used to clarify some of the confusions that exist in FCE research and practice, particularly the issue of measuring a client's function versus impairment. A redefinition of FCE for occupational therapy practice in the work assessment continuum is presented that supports occupational therapy practice and research in the area.     

Development and Validation of a Short-Form Functional Capacity Evaluation for Use in Claimants with Low Back Disorders

Objectives: Functional Capacity Evaluations (FCE) are used for making return-to-work decisions, yet FCE's modest predictive ability is currently outweighed by the administrative burden of testing. We attempted to develop a short-form FCE while maintaining comparable predictive ability. Methods: Three databases previously created for evaluating FCE predictive validity were used. Subjects were compensation claimants with low back disorders. FCE measures included items in the Isernhagen Work Systems’ FCE. Days until benefit suspension served as an indicator of return-to-work. Analysis included Cox regression. Results: Three items, floor-to-waist lift, crouching, and standing, were maintained in the short-form FCE. The short-form FCE was found to predict comparably to the entire FCE protocol in two validation cohorts (R ² difference<3%). Subjects meeting job demands on all three items consistently experienced faster benefit suspension. Conclusion: A short-form FCE for determining future work status in claimants with low back disorders was developed. A substantially abbreviated FCE may offer an efficient alternative.     

Relationships among age,body weight,resting heart rate,and performance in a new test of lift capacity

This study measured the relative contributions of age, gender, body weight, and resting heart rate to lift capacity in 531 healthy employed males and females in a cross-sectional model. The objectives of this study were to measure the contributions to lift capacity that are made by these variables and to develop an appropriate means to express the results of a new test of lift capacity. A formal training program was developed and administered to 110 health care professionals. Subsequently, each trained evaluator performed five tests on healthy volunteers. The effect of the independent variables were studied through the use of multiple regression and analysis of variance procedures. Results indicate that age, resting heart rate, and body weight are significant predictors of performance, with the last variable being the most important. A method to normalize lift capacity is presented in which the maximum acceptable weight lifted is divided by the evaluee's body weight to derive relative acceptable weight, a variable which is normally distributed. Those who use measures of lift capacity to describe performance must consider the effect of these variables in order to make valid interpretations of lift capacity test performance.     

Functional capacity evaluation: Rationale,procedure, utility of the kinesiophysical approach

The return to work process of an injured worker is dependent upon matching the physical abilities of the worker with physical demands of work tasks. Functional work movements and tasks are complex. Machines, equipment and isolated musculoskeletal testing have not produced data that is broad enough to project multi-faceted work ability. Functional capacity evaluations, which are sets of dynamic work tests, have seen a growing acceptance because of their whole-worker approach. The basic items of functional evaluations (lifting, carrying, bending, reaching, climbing) are compiled into a comprehensive test which results in information about the whole of work and overall ability of the worker. Projections into an eight-hour day and comparison to physical demands of the job are included in outcome of a functional capacity evaluation. The Kinesiophysical design approach also produces information on safety, compliance, movement characteristics and physical reasons behind work limitations. Utility of functional evaluation is exemplified when employers, and physicians use it as a basis for safe work return of the employee.     

Psychological factors affecting isokinetic trunk strength testing in patients with work-related chronic low back pain

Psychological factors are assumed to play a major role in pain-related work disability. Assessment of pain-related disability using a functional capacity evaluation, usually includes assessment of trunk strength and range of motion. Isokinetic strength testing is a method used to measure strength and function of isolated muscles and has been reported to be an objective, quantifiable assessment of trunk function. Given that psychological factors are purported to play a role in pain-related disability, it would be important to assess their influence on measurement of physical function. The present study was conducted to assess the influence of psychological variables on isokinetic trunk strength performance. One hundred and eighty-six consecutive male outpatients referred to a work-rehabilitation center were given a functional capacity evaluation. All patients had been out of work for at least 3 months with the chief complaint of low back pain. The evaluation included isokinetic trunk strength testing and measurement of psychological variables (pain levels, distress, pain coping, pain behavior, somatization, expectation to return to work) that have been known to contribute to pain-related disability. Data analyses revealed significant correlations among psychological variables and measures of trunk strength and function. The findings provide support for a relationship between psychological variables and isokinetic strength testing performance.     

Relationships among grip strength,work capacity,and recovery

The relationship between strength, fatigue, and work capacity is a central issue for occupational rehabilitation. Musculoskeletal impairments often are expressed functionally as a loss of strength. For work tasks that require strength, such impairments may have a detrimental effect on work capacity that is sufficient to be disabling. How important is strength as a component of work capacity? How do work capacity and strength affect recovery time from repetitive forceful upper extremity work ? A sample of 40 healthy subjects comprised of 20 males and 20 females was studied in a model that used the isotonic strength of each subject to set exercise levels for subsequent forceful repetitive gripping tasks. Resistance levels of 75%, 50%, and 25% of maximum were used for one-per-second repetitions until the subject could not maintain that pace. Isometric grip strength was measured after 1 minute of rest and after 5, 10, and 20 minutes. Results indicate that males and females do not differ in terms of their rate of recovery and that the best predictor of recovery time is the immediate measurement of strength loss following cessation of work activity.     

Reliability of occupational therapists in determining safe, maximal lifting capacity

Determination of an individual's lifting capacity is an important component in Functional Capacity Evaluation, which is widely used to delineate potential for work. Despite a recent surge in the number and types of Functional Capacity Evaluations, and therefore in approaches to determining lifting capacity, there has been limited research to support the reliability and validity of their use. This study evaluated the inter-rater reliability of five occupational therapists in determining safe maximal lifting capacity using a biomechanical approach. In addition, the use of an operational definition of a safe lift was examined to determine its effect on therapists' decision-making process and therefore the reliability of their ratings. The use of an operational definition was found to significantly affect therapists' decision-making process in differentiating safe from unsafe lifts, with all raters showing highly significant improvements in their ability to determine the safety of lifts from pre- to postdefinition ratings, according to McNemar's χ ² statistic. The provision of a definition also enhanced therapists' reliability of ratings, with kappa values that ranged from 0.47 to 0.74 predefinition changing to 0.56–0.82 postdefinition. Possible explanations for the change in decision-making are discussed and the need for ongoing evaluation of procedures used in Functional Capacity Evaluation, particularly with regard to the determination of lifting capacity, are highlighted.     

Does functional capacity evaluation predict recovery in workers' compensation claimants with upper extremity disorders?

Objectives

Functional capacity evaluations (FCEs) are commonly used to determine return‐to‐work readiness and guide decision making following work related injury, yet little is known of their validity. The authors examined performance on the Isernhagen Work Systems'' FCE as a predictor of timely and sustained recovery in workers'' compensation claimants with upper extremity disorders. A secondary objective was to determine whether FCE is more predictive in claimants with specific injuries (that is, fracture) as compared to less specific, pain mediated disorders (that is, myofascial pain).

Methods

The authors performed a longitudinal study of 336 claimants with upper extremity disorders undergoing FCE. FCE indicators were maximum performance during handgrip and lift testing, and the number of tasks where performance was rated below required job demands. Outcomes investigated were days receiving time‐loss benefits (a surrogate of return to work or work readiness) in the year following FCE, days until claim closure, and future recurrence defined as whether benefits restarted, the claim reopened, or a new upper extremity claim was filed. Cox and logistic regression were used to determine the prognostic effect of FCE crudely and after controlling for potential confounders. Analysis was performed separately on claimants with specific and pain mediated disorders.

Results

Most subjects (95%) experienced time‐loss benefit suspension within one year following FCE. The one year recurrence rate was 39%. Higher lifting performance was associated with faster benefit suspension and claim closure, but explained little variation in these outcomes (r² = 1.2–11%). No FCE indicators were associated with future recurrence after controlling for confounders. Results were similar between specific injury and less specific groups.

Conclusions

Better FCE performance was a weak predictor of faster benefit suspension, and was unrelated to sustained recovery. FCE was no more predictive in claimants with specific pathology and injury than in those with more ambiguous, pain mediated conditions.     

Safe Lifting in Patients with Chronic Low Back Pain: Comparing FCE Lifting Task and Niosh Lifting Guideline

Introduction: Both the floor-to-waist lifting task of the Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) and recommended weight limit (RWL) of the NIOSH produce safe lifting weights and are used world-wide nowadays. It is unknown whether they produce similar safe lifting weights. Aim of this study was to compare FCE performance on the floor-to-waist lifting task and RWL of the NIOSH lifting guideline for this task, in patients with chronic low back pain (CLBP). Methods: Ninety-two patients performed the FCE lifting task. RWL was calculated for this task. Performance was compared with RWL. A lifting index was calculated by dividing performance by RWL. Differences between groups with a lifting index ≤1, 1–3, and >3 were calculated for pain intensity, scores on the Roland Morris Disability Questionnaire (RMDQ) and work status. Results: Men lifted on average 32.5 kg (SD 15.4) and women 18.8 kg (SD 7.8). RWL for this task was 12.8 kg. Mean difference between performance and RWL was 15.0 kg (SD 14.7; range −8.8 to 59.2). The Roland Morris Disability score of patients with a lifting index ≤1 was significantly lower than patients with a lifting index 1–3 and >3. No difference in pain intensity and work status was found between groups. Conclusion: It was concluded that performance on the FCE floor-to-waist lifting task and RWL of the NIOSH for this task produce different safe lifting weights in individual patients with CLBP, which may result in contradictory recommendations about need for rehabilitation and return to work.     

Test–Retest Reliability of the Isernhagen Work Systems Functional Capacity Evaluation in Patients with Chronic Low Back Pain

The aim of this study was to investigate test–retest reliability of the Isernhagen Work System Functional Capacity Evaluation (IWS FCE) in a sample of patients (n = 30) suffering from Chronic Low Back Pain (CLBP) and selected for rehabilitation treatment. The IWS FCE consists of 28 tests that reflect work-related activities like lifting, carrying, bending, etc. In this study, a slightly modified IWS FCE was used. Patients were included in the study if they were still at work or were less than 1 year out of work because of CLBP. Participants' mean age was 40 years, the duration of low back pain ranged between 5 and 10 years. Fifteen patients (50%) were out of work for a mean of 17 weeks, and they all received financial compensation. Two FCE sessions were held with a 2-week interval in between. Means per session, 95% confidence intervals of the mean difference, one-way random Intra Class Correlations (ICC), limits of agreement, Cohen's kappa and percentage of absolute agreement were calculated where appropriate. An ICC of 0.75 or more, a kappa value of more than 0.60 and a percentage of absolute agreement of 80% were considered as an acceptable reliability. Tests of the IWC FCE were divided into tests with and tests without an acceptable test–retest reliability on the basis of the kappa values, the percentage of absolute agreement and the ICC values. Fifteen tests (79%) showed an acceptable test–retest reliability based on Kappa values and percentage of absolute agreement. Eleven tests (61%) showed an acceptable test–retest reliability based on ICC values.     

Practical Aspects of Functional Capacity Evaluations

Physicians, employers, insurers, and benefits adjudicators often rely upon functional capacity evaluations (FCEs) to determine musculoskeletal capacity to perform physical work, often with legal or occupational consequences. Despite their widespread application for several decades, a number of scientific, legal, and practical concerns persist. FCEs are based upon a theoretical model of comparing job demands to worker capabilities. Validity of FCE results is optimal with accurate job simulation and detailed, intensive assessments of specific work activities. When test criteria are unrelated to job performance, or subjective evaluation criteria are employed, the validity of results is questionable. Reliability within a subject over time may be adequate to support the use of serial FCE data collection to measure progress in worker rehabilitation. Evaluation of sincerity of effort, ability to perform complex or variable jobs, and prediction of injury based upon FCE data is problematic. More research, especially studies linking FCE results to occupational outcomes, is needed to better define the appropriate role for these evaluations in clinical and administrative settings.     

The reliability and validity of a measure of perceived functional capacity for work in chronic back pain

Psychosocial factors, including perceived disability and self-efficacy, are important determinants of outcome for individuals with chronic back pain. Consequently, there is a need for an evaluation and consideration of such factors in occupational rehabilitation. This study evaluated the reliability and validity of a tool, the Spinal Function Sort, as a measure of perceived capacity for work-related tasks with 42 rehabilitation clients with chronic back pain. Results provided support for the internal consistency (Cronbach's alpha of 0.97), test-rest reliability (ICC of 0.89) and construct validity of the Spinal Function Sort as a measure of perceived capacity for work-related tasks in persons with chronic back pain. Measures of similar constructs were significantly correlated with the Spinal Function Sort and were highly predictive of the Spinal Function Sort on multiple regression. Relationships between perceived work capacity and pain intensity and gender are discussed. The need for the consideration of perceived capacity in the evaluation and rehabilitation of persons with chronic back pain is highlighted.     

History, Design Characteristics, and Uses of the Pictorial Activity and Task Sorts

Development of the Pictorial Activity and Task Sort (PATS) technology in the field of Occupational Rehabilitation is described. The history of several PATS measures is traced, and each measure is briefly described. The use of these measures to efficiently collect data in functional capacity evaluation and to provide guidance in occupational rehabilitation is briefly described. Key design characteristics are presented and several recommendations are provided for future development of PATS.     

Concurrent validity of questionnaire and performance-based disability measurements in patients with chronic nonspecific low back pain

This study aimed to investigate the concurrent validity of two approaches to disability measurement in patients with chronic nonspecific low back pain (CLBP). It was hypothesized that if both are measuring the same construct, the instruments would lead to similar disability results and would correlate strongly (r > 0.75). The study compared the results of self-reported and performance-based measures of disability in 64 consecutive patients with CLBP. Participants mean age was 38.0 years, the mean duration of the current episode of back pain 9.9 months, and 90% were off work due to CLBP. The self-report measures used were: the Roland Disability Questionnaire (Roland); the Oswestry Disability Questionnaire (Oswestry); and the Quebec Back Pain Disability Questionnaire (Quebec). Performance was measured using the Isernhagen Work Systems Functional Capacity Evaluation (FCE). The mean scores from the self-report measure are as follows: Roland 13.5 (scale 0–24), Oswestry 28.2 (scale 0–100), Quebec 37.8 (scale 0–100) consistent with moderate to severe disability. In contrast the results from the performance-based measures suggested that the subjects should be able to work at a physical intensity level of moderate to heavy. Little to moderate correlation was observed between the self-report and performance-based measures (Spearman rank correlations: Roland-FCE (–0.20), p > 0.05; Oswestry-FCE (–0.52), p < 0.01; Quebec-FCE (–0.50), p < 0.01). Results are interpreted to suggest that both performance-based and self-report measures of disability should be used in order to obtain a comprehensive picture of the disability in patients with CLBP.     

Fatal occupational injuries among self-employed workers in North Carolina

BACKGROUND: Research suggests that rates of occupational injury and death may be higher among self-employed workers than in the wage and salaried population. This analysis was conducted to describe the demographic and occupational characteristics, as well as injuries, activities, and occupations of self-employed workers who are fatally injured on the job. METHODS: Characteristics of workers by type of employment were compared using data from the North Carolina Office of the Chief Medical Examiner, 1978-1994. Age-, activity-, and industry-specific fatality rates in self-employed workers (N=395) were contrasted to those privately employed (N=1,654). RESULTS: Highest fatal injury rates among the self-employed occurred in agriculture, retail, and transportation industries. Homicide deaths occurred more frequently among self-employed workers; deaths resulting from unintentional injuries occurred more frequently among non-self-employed workers. CONCLUSIONS: Elevated occupational fatality death rates among self-employed workers, especially in retail and transportation industries, provide justification for addressing work-related conditions of self-employed workers in North Carolina.     

The Use of Dexterity Tests in Hand Rehabilitation

A battery of American standardized tests for assessing dexterity was used in 15 patients undergoing rehabilitation after hand injuries and in 15 healthy controls. Our purpose was to identify tests that would discriminate healthy from non-healthy individuals with respect to functional motor skills in the hand. Out of the test battery including 4 tests and 10 subtests, the Crawford small parts dexterity test, the Purdue pegboard test, the Minnesota manual dexterity test and Valpar no. 4, two tests, the Crawford pin test and the Purdue right and left test, found to make a clear distinction between subjects with impaired hand function and those in the healthy group. The Purdue right/left/bilateral test, the Minnesota picking and turning tests, the Crawford screw test, the Purdue bilateral test and Valpar no. 4 also appeared useful, but had less capacity to discriminate between the two groups compared with the two tests already mentioned. We conclude that the tests presented in this study deserve a place in our current arsenal of instruments for evaluating dexterity, but a larger material is needed in order to make a more precise evaluation of these tests.