Effect of Computer Mouse Design on Risk Factors for Cumulative Trauma Disorderand on Patterns of Motor Coordination of the Forearm and Wrist in Skilled and Novice Users

摘要

The common, forearm pronated (FP) computer mouse was compared with a new forearmneutral (FN) computer mouse designed to reduce the risk of cumulative trauma disorders (CTD). Twenty experienced mouse users and 20 novice mouse users participated in evaluations of the two mouse types. Use of the FP mouse was associated with mean forearm pronation up to maximum, high mean wrist ulnar deviation, motions, of wrist radial ulnar deviation with intermittent occurrence of maximum ulnar deviation angles, and activation of the pronators and the wrist extensors at intensities between 8% maximum voluntary contraction (MVC) and 35% MVC at least 40% of the time. The FN mouse eliminated the postural and joint motion risk factors and reduced some muscular demands associated with postural risks. The FN mouse did not reduce mean wrist extension and it increased extensors capri radialis activation to higher intensity levels. The highest speed of performance was attained with the FN mouse. Novice users demonstrated a similar rate of improvement in speed of performance with both mouse designs. Skilled users demonstrated a remarkable degree of skill transfer. The study showed that risk factors for forearm and wrist CTD can be attributed to mouse operation as such.