“…They include four main sequential activations of muscle synergies timed at a specific phase of the step cycle, corresponding to limb touch-down, propulsion, lift-off, and swing (7,11,15,17,22,27). While the neuromuscular modules of adult locomotion have been thoroughly investigated (9,17,20,22,28,29), there is still limited knowledge about their development since birth (11,21,30,31). Here we consider the development of human locomotion.…”