A sEMG-based method for assessing the design of computer mice

Computer users who experience repetitive wrist movements and awkward hand positions are prone to developing upper extremity disorders. Manufacturers have designed various ergonomic mice in response to complaints of pain and discomfort related to computer mouse use. The objective of this work was to validate the use of surface electromyography (sEMG) in assessing the design of nonkeyboard input devices (computer mice). While holding the computer mouse in different grasp positions sEMG of the forearm and hand were recorded during a set of static tasks. The sEMG signal provided information regarding the level of muscle activity and the varied combinations of muscular effort needed to position the hand in a specified posture. A significant decrease in the level of sEMG activity was observed for the pronator muscles when subjects were tested using ergonomic computer mice. The sEMG-based method was validated to be sensitive to the impact of subtle differences in shape/design on the amplitude of the surface EMG data. We also proved a significant effect of hand size and grasp position on the level of muscle activity associated with different mice.