Two-Dimensional Motion Analysis of the Upper Limb Joint Movements of Skilled and Unskilled People During Kitchen Knife Handling

Abstract

A two-dimensional video-based motion analysis software was used to measure the angle of upper limb joints of people during their kitchen knife handling, and differences in upper limb movement based on their skill levels were examined. The results showed that skilled people began cutting with their shoulders extended and elbows bent; subsequently, they cut by bending their shoulders and extending their elbows, while moving their upper arms forward using the shoulders as pivot and moving the forearm-hand-knife in parallel and forward-downward directions without radial flexion of their hands. Unskilled people bent their shoulders less than did skilled people during cutting; through extension of their elbows or radial flexion of their hands, they exerted pressure by moving the forearm-hand-knife downward. Reduced shoulder bending during cutting results in increased downward movement of the ulnar styloid. Thus, awareness of shoulder posture may aid in efficiently mastering knife-handling skills.