Muscle activities in similar arms performing identical tasks reveal the neural basis of muscle synergies

• DOI: 10.1007/s00221-019-05679-9
• Publication Date: 2019-12-05T18:02:46Z
• Authors: Laura Pellegrino; Martina Coscia; Maura Casadio
• Keywords: Adult; Male; electromyography; human walking; upper limb; adaptation; Motor Activity; handedness; Upper Extremity; 03 medical and health sciences; 0302 clinical medicine; Humans; patterns; Muscle, Skeletal; robotic evaluation; Electromyography; Middle Aged; reaching; motor; manual asymmetries; Biomechanical Phenomena; kinematic synergies; movement control; activation; Female; hand; muscle synergies; Upper limb; Robotic evaluation; Reaching; Electromyography;MANUAL ASYMMETRIES; HUMAN WALKING; KINEMATIC SYNERGIES; MOVEMENT CONTROL; MOTOR; HAND; HANDEDNESS; PATTERNS; ACTIVATION; ADAPTATION

Are the muscle synergies extracted from multiple electromyographic signals an expression of neural information processing, or rather a by-product of mechanical and task constraints? To address this question, we asked 41 right-handed adults to perform a variety of motor tasks with their left and right arms. The analysis of the muscle activities resulted in the identification of synergies whose activation was different for the two sides. In particular, tasks involving the control of isometric forces resulted in larger differences. As the two arms essentially have identical biomechanical structure, we concluded that the differences observed in the activation of the respective synergies must be attributed to neural control.