Interventions for the primary prevention of work-related carpal tunnel syndrome

Objective: To evaluate interventions for the primary prevention of work-rel ated carpal tunnel syndrome (CTS). Selection Criteria: Studies had to include an engineering, administrative, personal, or multiple component intervention applied to a working or workin g-age population. All study designs that included comparison data were cons idered. Outcome measures included the incidence, symptoms, or risk factors for CTS, or a work-related musculoskeletal disorder of the upper extremity that included CTS in the definition. Results: Twenty-four studies met our inclusion criteria. Engineering interv entions included alternative keyboards, computer mouse designs and wrist su pports, keyboard support systems, and tool redesign. Personal interventions included ergonomics training, splint wearing, electromyographic biofeedbac k, and on-tile-job exercise programs. Multiple component interventions (e.g ., ergonomic programs) included workstation redesign, establishment of an e rgonomics task force,job rotation, ergonomics training, and restricted duty provisions. Multiple component programs were associated with reduced incid ence rates of CTS, but the results are inconclusive because they did not ad equately control for potential confounders. Several engineering interventio ns positively influenced risk factors associated with CTS, but the evaluati ons did not measure disease incidence. None of the personal interventions a lone was associated with significant changes in symptoms or risk factors. A ll of the studies had important methodologic limitations that may affect th e validity of the results. Conclusions: While results from several studies suggest that multiple compo nent ergonomics programs, alternative keyboard supports, and mouse and tool redesign may he beneficial, none of the studies conclusively demonstrates that the interventions would result in the primary prevention of carpal tun nel syndrome in a working population. Given the societal impact of CTS, the growing number of commercial remedies, and their lack of demonstrated effe ctiveness, the need for more rigorous and long-term evaluation of intervent ions is clear. Funding for intervention research should prioritize randomiz ed controlled trials that include: (1) adequate sample size, (2) adjustment for relevant confounding variables, (3) isolation of specific program elem ents, and (4) measurement of long-term primary outcomes such as the inciden ce of CTS, and secondary outcomes such as employment status and cost.