Wrist Twist Working Posture’s Muscles Activity and Potential Energy Analysis via Human Digital Modelling

Pronation and supination are a pair of unique movements possible only at the to flip the palm either facing superiorly (supination) or inferiorly (pronation). Muscles in the forearm work together by pulling on the radius bone of the forearm. This posture was concerned in work ergonomics assessments but still was not clarified about the postures variety. The objective of this research is to evaluate the postures variance range via kinesiology variables. A digital male human model was developed according to the Malaysian population anthropometry data with AnyBody Modelling System (AMS). The model was simulated with the constraints of static wrist pronation and supination postures for 30 min duration at a constant elbow flexion 90° (neutral) and 0° for both wrist flexion abduction to find the muscles activity and potential energy differences across the range of motion. The simulation result showed that co-contraction occurred between agonist and antagonist muscles on dynamic balance pronation movement (postures) act in a non-proportionate relationship. The other 2 outputs of maximum muscles activity and potential have been analyzed to generate the statistical risk index across the movement variety based on the outputs range. It is concluded that wrist twist postures range of motion varies by both muscles activity and potential energy which can be used to differentiate the posture’s angles.