The upper extremity loading during typing using one, two and three fingers

Abstract

This study aimed to evaluate the effect of the number of fingers used during typing on the biomechanical loading on the upper extremity. Six subjects typed in phone numbers using their right hand on a stand-alone numeric keypad in three conditions: (1) typing using the index finger; (2) typing using the index and the middle fingers; (3) typing using the index, middle and ring fingers. Typing with three fingers decreased wrist posture deviation, decreased angular velocity at the wrist, elbow and shoulder joints, and decreased peak to peak torques at the wrist and shoulder joints compared to single finger typing, while no difference was found between one and two finger typing. These results demonstrated that different computer keyboarding styles affect the biomechanical loading on the upper extremity. © 2011 Springer-Verlag.