Effects of wrist posture, pace and exertion on discomfort

This study investigated the effects of exertion, pace and level of simple and combined flexion/extension and radial/ulnar deviation of the wrist on discomfort for simple repetitive exertions. Eight male subjects participated in the study and the level of exertion and angular deviation were defined relative to the maximum strength and range of motion (ROM) of the subjects, respectively. Extreme flexion caused higher discomfort than the other simple types of deviation, and the combination of flexion and ulnar deviation resulted in higher discomfort than the other types of combined deviation. Exertion was the most significant factor, followed by level of deviation and then pace. These models relating combinations of posture, force and pace to subjective discomfort can be used in conjunction with man modelling packages to identify and eliminate stressful tasks before disorders occur.