Muscle Coordination, Motor Synergies, and Primitives from Surface EMG

To investigate neural control strategies, muscle activity must be measured during motor behavior. Recent advances in the investigation of the neural control of movement have led to a re-examination of the mechanisms of sensorimotor integration in the central nervous system (CNS) and in the spinal circuitry in particular. This chapter considers different approaches used to uncover the modular organization of the motor output in human behaviors such as responding to postural perturbations, reaching with the arm, and locomotion, as well as its plasticity and flexibility in movement disorders. It also investigates the strategies that the CNS employs to coordinate the activation of many muscles start from electromyographic (EMG) signals recorded simultaneously from many muscles. Different muscle synergies models are used to decompose the EMG envelopes using appropriate factorization algorithms. The chapter further considers the spatiotemporal organization of the activity patterns of leg and trunk muscles during locomotion.