Nested case-control study of hand and wrist work-related musculoskeletal disorders in carpenters.

Unionized carpenters (n = 522) participated in a telephone interview regarding their jobs and musculoskeletal symptoms. From this group, a nested case-control study was conducted on 25 symptomatic carpenters who met a hand or wrist work-related musculoskeletal disorder (WMD) case definition and on 35 asymptomatic carpenters who were of similar age, sex, height, and weight. The purpose of the study was to determine if questionnaire symptom data could be used to estimate the prevalence of hand/wrist WMDs. To test this hypothesis, a subset of subjects underwent physical examination and electrodiagnostic testing to determine if these symptom-derived cases had findings of carpal tunnel syndrome or other hand or wrist musculoskeletal disorders. Standardized upper extremity physical examinations and unilateral ulnar and median nerve conduction studies were administered. Physical examination findings of CTS were significantly increased among WMD cases. Mean median sensory and motor distal latencies were significantly longer (P < 0.05) and median sensory amplitudes smaller in cases compared to controls. Median relative to ulnar sensory and motor latencies also were longer in cases. A median mononeuropathy at the wrist was found in 78% of the cases. These findings suggest that symptom-derived WMD data are useful in estimating estimating the prevalence of CTS among carpenters.