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When animals walk overground, mechanical stimuli activate various receptors located in muscles, joints, and skin. Afferents from these mechanoreceptors project to neuronal networks controlling locomotion in the spinal cord and brain. The dynamic interactions between the control systems at different levels of the neuraxis ensure that locomotion adjusts to its environment and meets task demands. In this article, we describe and discuss the essential contribution of somatosensory feedback to locomotion. We start with a discussion of how biomechanical properties of the body affect somatosensory feedback. We follow with the different types of mechanoreceptors and somatosensory afferents and their activity during locomotion. We then describe central projections to locomotor networks and the modulation of somatosensory feedback during locomotion and its mechanisms. We then discuss experimental approaches and animal models used to investigate the control of locomotion by somatosensory feedback before providing an overview of the different functional roles of somatosensory feedback for locomotion. Lastly, we briefly describe the role of somatosensory feedback in the recovery of locomotion after neurological injury. We highlight the fact that somatosensory feedback is an essential component of a highly integrated system for locomotor control. 

This chapter reviews major principles of neural control of movement proposed by N. A. Bernstein based on his biomechanical studies of human movements and published in his 1947 book ‘On Construction of Movements’. These principles include the hierarchical organization of the motor control system; synergistic sensorimotor control; the principle of sensory corrections, and the principles of repetition without repetition and fixating and subsequent releasing kinematic degrees of freedom during motor skill acquisition. These principles simplify control of the musculoskeletal system with redundant degrees of freedom and unpredictable effects of reactive and muscle forces arising in multi-segment kinematic chains. We also discuss the relevant contemporary research that has been inspired by and further developed Bernstein’s ideas. We demonstrate, in particular, examples of complex muscle and kinematic synergies organized by different levels of the motor control system, consequences of loss of proprioceptive sensory corrections on movement coordination, and emergence of economical and stable kinematic and muscle invariant movement characteristics in the process of skill acquisition by trials and errors. We conclude this chapter with motor control related parables told by N. A. Bernstein to one of the authors (VMZ).