Prevention of musculoskeletal disorders among VDT users.
Gerr-F; Marcus-M; Monteilh-C
NIOSH 2004 Jan; :1-62
We performed the first randomized trial of specific ergonomic and postural interventions among persons using computer keyboards for more than 15 hours per week. Two specific sets of postural interventions were studied: 1) postural interventions based on the results of a major prospective study of musculoskeletal disorders among VDT users (RO1 OH 03160) and 2) postural interventions based on recommendations of OSHA, NIOSH, and several computer manufacturers. The incidence of neck/shoulder symptoms and hand/arm symptoms during six months of follow-up among individuals in these two intervention groups was compared to the incidence in a third group of computer users who did not receive any intervention. Approximately 440 individuals agreed to participate in the study, signed informed consent forms and completed a screening questionnaire designed to determine eligibility for randomization. Approximately 90 individuals were ineligible due to existing musculoskeletal symptoms at entry into the study. A total of 376 individuals were randomized into one of three intervention groups: the Emory/GT intervention (group A), the OSHA/conventional intervention (group B), and a group with no intervention (group C). For individuals in the intervention groups, study staff adjusted workstations, where possible, and trained individuals to assume the intervention postures. Individuals reported musculoskeletal symptoms on a weekly diary: Participants who reported discomfort intensity of 6 or greater on a 0-10 visual analog scale or who reported musculoskeletal symptoms requiring use of analgesic medication were considered symptomatic. Compliance with all components of the intervention was attained for only 25% of individuals in group A and for only 38% of individuals in group B. Difficulty in attaining compliance was largely due to the inflexibility of workstation configurations. There were no significant differences in the incidence of musculoskeletal symptoms among the three groups. The number of individuals who developed arm or hand symptoms was 22 (18.3%) in group A, 25 (20.2%) in group B and 25 (21.7%) in group C. The number of individuals who developed neck or shoulder symptoms was 38 (33.3%) in group A, 36 (31.9%) in group B and 33 (30.3%) in group C. Postural interventions are difficult to implement because of the inflexibility of workstations commonly in use. This study provides evidence that workplace postural interventions are unlikely to reduce the risk of upper extremity musculoskeletal symptoms among computer users.
Injuries; Injury-prevention; Musculoskeletal-system-disorders; Posture; Ergonomics; Arm-injuries; Hand-injuries; Neck-injuries; Questionnaires; Worker-health; Work-environment; Risk-factors; Video-display-terminals
Final Grant Report
National Institute for Occupational Safety and Health
Emory University, Atlanta, Georgia