Original article

Scand J Work Environ Health 2000;26(5):390-397    pdf


Differences between work methods and gender in computer mouse use

by Wahlström J, Svensson J, Hagberg M, Johnson PW

Objectives The aim of this study was to investigate whether gender or different methods of operating a computer mouse have an effect on performance and musculoskeletal load in the use of a computer mouse.

Methods Thirty experienced computer mouse users, 15 men and 15 women, participated in the study. Electromyography (right first dorsal interossei, right extensor digitorum and right and left trapezius), a force-sensing mouse, and subjective ratings were used to register muscular load. An electrogoniometer was used to register the wrist movements. The subjects worked with 3 different methods, their own, a wrist-based method and an arm-based method. Gender comparisons were made when the subjects used their own method.

Results The women worked with greater extension and range of motion and tended to work with a greater ulnar deviation of the wrist. They also applied higher forces to the mouse when expressed as a percentage of a maximum voluntary contraction and had higher muscular activity in the right extensor digitorum. When using the arm-based method, the subjects worked with greater wrist extension, had higher muscle activity in the right and left trapezius muscles and had the highest ratings of perceived exertion in the neck and shoulder. The wrist-based method resulted in higher forces being applied to the sides of the mouse and the highest ratings of perceived exertion in the wrist and hand-fingers.

Conclusions Gender differences were found for musculoskeletal load, and for most of the measured variables the women worked with higher loads than the men. The work method affected performance and musculoskeletal load. Finally, subjective measures appeared to have some utility in characterizing muscular load.