Determinants of return-to-work among low back pain patients.

This prospective study identifies physical, behavioral, and psychosocial correlates of subsequent employment status in a sample of low back pain patients. The sample of 150 subjects was drawn from 2 populations of persons with chronic low back pain: 87 individuals who were receiving care at a university low back pain clinic, and 63 individuals who had applied for (but not yet received) Social Security compensation on the basis of low back pain. All subjects had worked at least 3 months prior to their latest unemployment period and were currently out of work. Initial assessment included a medical history, physical examination, biomechanical testing, psychiatric interview, and MMPI testing. All subjects were followed up 6 months later to determine whether they had returned to work. Cross-sectional group comparisons at the time of initial assessment showed that, after controlling for the effects of age, the two samples differed on several physical and biomechanical measures, the Social Security group reflecting a more chronic picture. Group differences on physical variables were found, but most significant differences disappeared when adjusted for length of time out-of-work. Longitudinal analyses showed that few objective physical or biomechanical measures were associated with return-to-work at 6 months, while a number of psychosocial variables were significant predictors of 6-month work status. The data suggest that exclusive reliance on the physical examination to determine level of disability, without consideration of psychosocial conditions, and without adjusting for the confounding effects of age and length of time out-of-work, is not empirically justified. Logistic regression analysis was used to ascertain the relative contribution of each predictor to outcome and to illustrate the hypothetical effects of changes in the levels of selected risk factors on the likelihood of return-to-work. Implications for interventions with low back pain patients are discussed and future research directions suggested.

Workers' Compensation and return-to-work in low back pain.

The relationship of Workers' Compensation and litigation to low back pain (LBP) outcome is not established in the literature. Our study investigated the characteristics of disabled persons applying for Worker's Compensation or employing a lawyer, the factors predicting receipt of compensation, and the effects of compensation and litigation on employment outcome. One hundred sixty-nine unemployed persons with LBP were assessed by medical history, physical exam, biomechanical testing, psychiatric interview, and MMPI. Subjects were asked whether they had applied for compensation, received it, or had employed a lawyer. Six months later, subjects were asked about their employment and compensation status. Neither compensation status nor involvement of a lawyer significantly improved prediction of employment status 6 months later. Receipt of compensation predicted better outcome in those at risk for poor outcome due to external locus of control. Factors predicting failure to obtain compensation over 6 months, having applied, include education, spinal flexion, ability to do daily activities and affective inhibition. Neurological dysfunction did not predict receipt of compensation in univariate or multivariate analyses; emotional distress reduced the probability of receiving compensation, after controlling for severity of spinal dysfunction. Receipt of compensation and use of a lawyer did not reduce the probability of RTW in disabled persons in the present sample, but increased the likelihood of return to work for groups of individuals at higher risk such as those with external locus of control. Although compensation is awarded on the basis of physical evaluation under the present system, the present findings suggest that the likelihood of receiving compensation is also significantly determined by level of emotional distress.

Validity and reliability of an internet-based temporal gait assessment tool with healthy adults: a pilot study.

OBJECTIVES: To assess in healthy adults the validity and the inter- and intrarater reliability of the Internet-based Shaw Gait Assessment (SGA). DESIGN: Concurrent test-retest reliability and validity study with participants, 4 raters, and the Elite motion analysis system (used as the criterion standard). SETTING: Motion analysis laboratory in a university physical therapy department. PARTICIPANTS: Convenience sample of 16 healthy men and women (age range, 28-53y). INTERVENTION: Each subject performed 2 consecutive walks "at a comfortable pace" on a 6-m walkway. A video camera from the Elite motion analysis system filmed reflective markers, which were attached to subjects' shoes, and the reflective markers provided the criterion standard. Four raters simultaneously recorded each walk by using laptop computers and the SGA. MAIN OUTCOME MEASURES: Paired t test (5% level) for average differences between each test and retest for raters and the Elite; Pearson correlations, limits of agreement, and coefficients of variation (CVs) for validity of the tool; intraclass correlation coefficients (ICCs) for inter- and intrarater reliability. RESULTS: Pearson product moment correlation coefficients between each of the raters and the Elite ranged from .92 to .95 for speed, from .85 to .97 for cadence, from .87 to .92 for step length, from .61 to .84 for left advance limb time, and from .68 to .83 for right advance limb time. Pooled CVs for all variables were below 8% for all raters and the Elite. Pooled ICCs for intrarater reliability were .89 for speed, .99 for cadence, .84 for step length, .76 for left limb advance time, and .84 for right limb advance time. Interrater ICCs were .89 for speed, .82 for cadence, .76 for step length, .66 for left limb advance time, and .81 for right limb advance time. CONCLUSIONS: The SGA is a valid and reliable tool for several key temporal measures of gait in a healthy adult population.

Comparison of three lumbar orthoses using motion assessment during task performance.

STUDY DESIGN: Four conditions (three orthoses, one no orthosis), full cross-over, randomized order, 12 subjects tested 3 months after a lumbar surgical arthrodesis. OBJECTIVES: To assess whole torso and lumbar motions and comfort for each orthoses condition during performance of activities of daily living. SUMMARY OF BACKGROUND DATA: Previous noninvasive studies measured whole torso (not just lumbar) movement. Recent development of a low profile, flexible, strain-gauged device ("Lordosimeter") facilitated this study. MATERIALS AND METHODS: The Lordosimeter was taped to the skin along the midline of the lumbosacral region. Orthoses studied were Boston anterior opening, Aspen lumbosacral, and Cybertech. Specified activities of daily living were performed for each orthosis condition. Subject effort during the flexion/extension task was assessed by surface electromyography (EMG). Comfort was assessed by visual analog scale. RESULTS: There were no significant differences in EMG between orthoses. For lumbar flexion, trunk flexion, total lumbar motion, and total trunk motion, the mean values for Aspen and Boston (but not Cybertech) were significantly smaller than for no orthosis for most of the tasks and there were no significant differences between Aspen and Boston. The total lumbar motion allowed by each orthosis (averaged across tasks and relative to the no orthosis condition) was 81% for Aspen, 79% for Boston, and 97% for Cybertech. The comfort rating averaged across tasks was 2.24 for Aspen, 4.12 for Boston, and 3.92 for Cybertech (0 = very comfortable, 10 = very uncomfortable). Aspen was significantly more comfortable than Boston or Cybertech. Boston and Cybertech did not differ significantly. CONCLUSIONS: The Lordosimeter is useful for measuring lumbar motion during orthosis wear. The Aspen and the Boston orthoses provided significant flexion-extension motion restriction compared with no orthosis, but for almost all of the motion measures did not differ from each other. The Cybertech did not differ significantly from the no orthosis condition. The Aspen orthosis was rated significantly more comfortable than the Boston or the Cybertech.