Role of Biomechanical Factors in Resolution of Carpal Tunnel Syndrome Among a Population of Workers.

Abstract

Identify if Carpal tunnel syndrome (CTS) symptoms vary by measured biomechanical exposures. A nested prospective cohort within a large, multicenter, 8-year cohort study. The CTS case definition was tingling/numbness in 2+ median nerve-served digits plus a nerve conduction study consistent with CTS. Workers were assigned to: (1) low (strain index [SI] less than or equal to 6.1), and (2) high (SI more than 6.1) job groups. Among 1201 workers, 106 had CTS. Those in the high SI group became and remained symptom-free for at least 3 months, faster than the low SI group, adjusted hazard ratio (HR) = 2.07 (95% confidence interval [CI] = 1.21 to 3.56, P = 0.008). Only surgical release trended towards resolving CTS. Light duty had no impact, and job change was associated with delayed symptoms resolution. High biomechanical exposures paradoxically predicted faster improvement in CTS and light duty did not result in symptom resolution.