Carpal tunnel syndrome (CTS) is a condition where the median nerve, one of two main nerves to the hand, is compressed at the wrist, leading to pain in the hand, wrist and sometimes arm, and numbness and tingling especially in the thumb, index and middle finger. Weakness of the thumb muscles can also occur in severe cases. It affects approximately three per cent of the population, more commonly women.
Surgical treatment for CTS involves opening the carpal tunnel, the tunnel in which the median nerve passes through the wrist. Non-surgical treatments include medications, exercises, splinting and ergonomic interventions. Ergonomic interventions, such as keyboard modification, allow the hand to be used while the wrist is positioned in a straight position (neither flexed, extended or deviated to either side). In this straight (or neutral) wrist position the tunnel through which the median nerve passes is at its most capacious. This position is expected theoretically to place the least pressure on the median nerve.
This review aimed to find out how effective ergonomic treatments were in treating CTS. Only two studies were found (involving 105 participants). Both were designed to minimise research biases, but neither was of high quality. Neither study assessed short-term overall improvement, adverse effects or need for surgery as outcomes. One small study (25 participants) found an ergonomic keyboard reduced pain after 12 weeks but the second study reported no difference in pain severity between the keyboard groups at six months. Neither study found improvements in hand function or signs of CTS by people using ergonomic computer keyboards more than those experienced by people using standard keyboards. Based on the two studies in this review, which represent all the available evidence of sufficient quality for inclusion, there is no strong evidence for or against the use of ergonomic keyboards for the treatment of CTS.