American Journal of Industrid Medicine zyx 11543-358 zy (1987) Occupational Factors and Carpal Tunnel Syndrome Barbara A. Silverstein, PhD, Lawrence J. Fine, MD, and Thomas J. Armstrong, PhD Carpal tunnel syndrome (CTS) is the most commonly reported nerve entrapment syn- drome. The prevalence of CTS among 652 active workers in jobs with specific hand force and repetitiveness characteristics was estimated. The prevalence of CTS ranged from 0.6% among workers in low force-low repetitive jobs to 5.6% among workers in high force-high repetitive jobs. When controlling for potential confounders, the odds ratio for the high force-high repetitive jobs was more zyxw than 15 (p zyx < .Ol) compared to the low force-low repetitive jobs. High repetitiveness appears to be a greater risk factor than high force (odds ratio of zyxwv 5.5, p < .05 versus 2.9 and not statistically significant). Key words: repetitive trauma, Carpel tunnel syndrome, nerve entrapment INTRODUCTION Carpal tunnel syndrome (CTS) is the most commonly reported nerve entrapment syndrome [Phalen, 19721. Nonoccupational factors reported to be associated with carpal tunnel syndrome include several chronic diseases (rheumatoid arthritis, gout, diabetes mellitus, hypothyroidism), congenital defects such as anomolous muscles, acute trauma to the wrist, age, female gender [Tamer, 1959; Kendall, 1960; Phalen, 19721, birth control pill use [Sabour and Fadel, 19701, pregnancy [Massey, 19781, bilateral oophorectomy [Cannon et al, 19811, and wrist size or shape [Gelmers, 1981; Johnson et al, 19811. Occupational factors reported to be associated with carpal tunnel syndrome include forceful and repetitive hand motions, awkward postures, mechanical stress at the base of the palm, and vibration [Rothfleisch and Sherman, 1978; Armstrong and Chaffin, 1979; Cannon et al, 1981; Armstrong, 1983; Feldman et al, 19831. Despite increased worker and management concern and media attention [Lublin, 19831, there has been little documentation of actual incidence or prevalence of occupationally related carpal tunnel syndrome in the scientific literature. The main objective of this cross-sectional investigation was to determine if forceful and repeti- tive job attributes were positively associated with symptoms and physical signs of carpal tunnel syndrome (CTS) . Department of Environmental and Industrial Health, The University of Michigan, Ann Arbor. Address reprint requests to Barbara A. Silverstein, PhD, Department of Environmental and Industrial Health, University of Michigan, Ann Arbor, MI 48109. Accepted for publication August 25, 1986. zyxwv 0 1987 Alan R. Liss, Inc.