Immediate Effect of Mirror Therapy Using Pegboard Training on Hand Function and Muscle Activities in Individuals with Asymmetrical Hand Function

Objectives: Hand function is critical for daily life and work, especially with the use of electronic devices. This study determined the effect of mirror therapy in individuals with asymmetrical hand function. Method: Forty-two men with asymmetrical hand function were recruited. All participants were randomly divided into two groups: sham control (n = 21) and mirror therapy (n = 21). Both groups were tested before and after training using the 9-hole peg test (9HPT). The sham control group received pegboard training, and the mirror therapy group received mirror therapy using the pegboard. During training, hand muscle activities were recorded using a surface electromyography. Data were analyzed using the t-test and Mann-Whitney U test. Results: Non-dominant hand function on the 9HPT showed significant improvement in the mirror therapy group compared with the sham control group (p = 0.021). The percentage of asymmetric hand function was also improved in the mirror therapy group. Muscle activities of the non-dominant hand were not significantly different between groups. Discussion: Mirror therapy using the pegboard had an immediate effect on improving non-dominant hand function. This finding has implications for possible preventive strategies against common hand problems and for improving the efficient use of both hands.