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.
Rocky Mountain Center for Occupational and Environmental Health University of Utah (Dr Cardona, Dr Thiese, Dr Wood, and Dr Hegmann); College of Health Sciences University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (Dr Kapellusch); Department of Mechanical Engineering University of Utah (Dr Merryweather), Salt Lake City, Utah.
Address correspondence to: Kurt T. Hegmann, MD, MPH, Rocky Mountain Center for Occupational and Environmental Health, University of Utah, 391 Chipeta Way, Suite C, Salt Lake City, UT 84108 (firstname.lastname@example.org).
Clinical Significance: High biomechanical exposures predict faster improvement in CTS symptoms. Either light duty or job change do not appear to play a role in resolving symptoms and infer that the automatic institution of job limitations is unlikely to be successful. Only surgical release trended towards providing relief of CTS symptoms.
Each author worked at their respective institutions (see above). Level of Evidence: Level II, Prospective Cohort Study.
Sources of funding: Funded, in part, by CDC/NIOSH Research grant 1 U 01 OH007917-01 and CDC/NIOSH Training grant 3TC42OH008414.
Conflicts of Interest: None declared.