CUMULATIVE TRAUMA DISORDERS IN THE UPPER EXTREMITIES - RELIABILITY OFTHE POSTURAL AND REPETITIVE RISK-FACTORS INDEX

Objective: This study addresses test-retest reliability of the Postura l and Repetitive Risk-Factors Index (PRRI) for work-related upper body injuries. This assessment was developed by the present authors. Desig n: A repeated measures design was used to assess the test-retest relia bility of a videotaped work-site assessment of subjects' movements. Su bjects: Ten heavy users of video display terminals (VDTs) from a local banking industry participated in the study. Setting: The 10 subjects' movements were videotaped for 2 hours on each of 2 separate days, whi le working on-site at their VDTs. Main Outcome Measure: The videotaped assessment which utilized known postural risk factors for developing musculoskeletal disorder, pain, and discomfort in heavy VDT users (ie, repetitiveness, awkward and static postures, and contraction time), w as called the PRRI. The videotaped movement assessments were subsequen tly analyzed in 15-minute sessions (five sessions per 2-hour videotape , which produced a total of 10 sessions over the 2 testing days), and each session was chosen randomly from the videotape. The subjects' mov ements were given a postural risk score according to the criteria in t he PRRI. Each subject was therefore tested a total of 10 times (ie, 10 sessions), over two days. The maximum PRRI score for both sides of th e body was 216 points. Results: Reliability coefficients (RCs) for the PRRI scores were calculated, and the reliability of any one session m et the minimum criterion for excellent reliability, which was .75. A t wo-way analysis of variance (ANOVA) confirmed that there was no statis tically significant difference between sessions (p <.05). Calculations using the standard error of measurement (SEM) indicated that an indiv idual tested once, on one day and with a PRRI score of 25, required a change of at least 8 points in order to be confident that a true chang e in score had occurred. The significant results from the reliability tests indicated that the PRRI was a reliable measurement tool that cou ld be used by occupational health practitioners on the job site. (C) 1 997 by the American Congress of Rehabilitation Medicine and the Americ an Academy of Physical Medicine and Rehabilitation.