Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption

• DOI: 10.1371/journal.pcbi.1004737
• Publication Date: 2016-02-11T18:47:59Z
• Authors: Joshua M. Inouye; Francisco J. Vale...
• Keywords: Work space; Motor Control; Impedance Control

Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of in the context reaching movements postural tasks have produced divergent findings, this study explores whether use by central nervous system (CNS) can resolve these findings also provide insights mechanisms In study, we phrase debates at conceptual level interactions between neural degrees freedom constraints. This allows us examine ability experimentally-observed synergies—correlated activations—to consumption stiffness component endpoint impedance. our nominal 6-muscle planar arm model, desired size, shape, orientation ellipses, are expressed as linear constraints that define set feasible activation patterns. Quadratic programming predict how be minimized throughout workspace given those We show presence drastically decreases CNS vary properties even preclude minimize energy. Furthermore, capacity consumption—when available—can greatly affected posture. Our computational approach helps reconcile conclusions about task-specific regulation synergies. But more generally, results further evidence benefits disadvantages go hand-in-hand structure patterns afforded mechanics task These will help design experiments elucidate interplay learning, plasticity, versatility pathology neuromuscular systems.