A systematic review 1 including 24 studies with a total of 10 120 subjects was abstracted in DARE. While results from several studies suggest that multiple component ergonomics programmes, alternative keyboard supports, and mouse and tool redesign may be beneficial, none of the studies conclusively demonstrated that the interventions would result in the primary prevention of carpal tunnel syndrome (CTS) in a working population.
Given the societal impact of CTS, the growing number of commercial remedies, and their lack of demonstrated effectiveness, the need for more rigorous and long-term evaluation of interventions is clear.
A Cochrane review [Abstract]2 included two trials (105 participants) with diagnosed CTS comparing ergonomic versus placebo keyboards. Neither trial assessed the primary outcome (short-term overall improvement) or adverse effects of interventions. In one small trial (25 participants) an ergonomic keyboard significantly reduced pain after 12 weeks (MD -2.40; 95% CI -4.45 to -0.35) but not six weeks (MD -0.20; 95% CI -1.51 to 1.11). In this same study, there was no difference between ergonomic and standard keyboards in hand function at six or 12 weeks or palm-wrist sensory latency at 12 weeks. The second trial (80 participants) reported no significant difference in pain severity after six months when using either of the three ergonomic keyboards versus a standard keyboard.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in interventions and outcomes) and by imprecise results.
Primary/Secondary Keywords