Changes in mechanical control of movement during the first 5 months of independent walking: a longitudinal study

Insight into neuromuscular control of movement is gained through an understanding of the mechanical causes of movement. Data on new walkers' net joint moments is scarce, however, although those moments can be considered the direct cause of movement. The authors' goal in this research project was to characterize net joint moments in toddlers (N = 10) during the first 5 months of independent walking and to discuss their role in mechanical control of walking. The authors modeled leg segments as oscillating pendulums fixed at the proximal joint and investigated the relationship between force and movement. Their investigation revealed that at the onset of independent gait, walking was primarily hip driven. Furthermore, the toddlers seemed to experience problems in uncoupling active and passive control around the joints. Changes in mechanical control of walking were observed after 3 to 4 months of independent walking. The changes were more obvious at the hip and the knee joint than at the ankle.