Evaluation of a Pose-Shared Synergy-Based Isometric Model for Hand Force Estimation: Towards Myocontrol

In this work the authors investigated whether the muscle synergies concept could improve the isometric hand force estimation. Electromyographic (EMG) activity from 9 arm muscles and hand forces applied at the Light-Exos Exoskeleton end-effector were recorded during isometric contractions in several workspace points lying on the parasagittal plane crossing the shoulder joint. The muscle synergies were extracted in two different ways according to the statements that the muscle primitives are ‘Arm Pose Related’ or ‘Arm Pose Shared’. From the pre-processed EMG signals the authors then estimated the hand forces using three methods. The results showed that the muscle synergy concept improves the isometric force estimation paving the way for a synergy-based myoelectric control.