CONCURRENT VALIDITY OF THE ERGOS WORK SIMULATOR VERSUS CONVENTIONAL FUNCTIONAL-CAPACITY EVALUATION TECHNIQUES IN A WORKERS COMPENSATION POPULATION

A prospective blinded cohort study was performed in an interdisciplinary vocational evaluation program to investigate the concurrent validity of the ERGOS work simulator in comparison to current methods of evaluation. Seventy men and eight women, aged 22 to 64 years, who attended for a 2-week physical capacity assessment participated in the study. Physical activity factors as defined by the Canadian Classification and Dictionary of Occupations and the American Dictionary of Occupational Titles were assessed for all subjects under three evaluation conditions: the ERGOS work simulator, an exercise-oriented physical evaluation by a rehabilitation therapist, and performance of project-format industrial tasks. In addition, 17 men and 7 women were assessed with VALPAR standardized work sample tests. The statistical significance of the relationships between results obtained by the various evaluation methods was examined. There was a strong correlation between the ERGOS dynamometry and the clinical assessment of strength for all standard movements tested (P < .001). The Methods Time Measurement rating by the ERGOS for dexterity variables, according to industrial engineering standards, tended to rate subjects as more restricted than did the clinical evaluators. There was a significant relationship (P < .001) between the ''overall physical activity rating''from ERGOS dynamometry, clinical evaluation, and performance in an industrial workshop setting. There was also a significant relationship (P < .001) between the ''overall physical activity rating'' for endurance of a full workday produced by the 4-hour ERGOS evaluation and by the 2-week functional capacity evaluation. The results of this study indicate that a 4-hour ERGOS evaluation yields information on strength and endurance for industrial physical activity that is comparable with the information obtained from a comprehensive interdisciplinary 2-week functional capacity evaluation performed in multiple settings.