Spatiotemporal Patterns of Corticomuscular Interactions in Locomotion

This study addressed the synergistic effects apparent at the cortical and muscular levels during locomotor activity performed under conditions in which the lower limbs are supported horizontally. The spatiotemporal structure of synergies was studied using data matrix factorization methods. Control of movement structure is shown to be realized primarily through three muscle synergies. Synchronization of the activity of the motor, associative, visual, and sensorimotor areas of the cortex on both sides is due to the specific characteristics of locomotion in conditions of gravitational unloading and the associated features of receptor signaling. The components identified, evidencing synchronization of different areas of the cortex on the right and left sides, may reflect control processes associated with the control of alternating activation of the flexor and extensor muscles of the contralateral limb in the process of locomotion. Data on the spatiotemporal structuring of cortical activity indicate separate control of muscle synergies via synchronization of cortical commands and the temporal organization of muscle synergies in the frequency range 0.30–8.00 Hz. These patterns may reflect operation of a rhythm-generating mechanism involved in controlling cyclic activity.