The cyclical flexion and extension motions of a leg during walking result from activity at which level of the nervous system
Cerebral coex
Cerebellum
Globus pallidus
Spinal cord
The spinal cord is the locus of complex patterns of rhythmical motions such as to-and-fro movement of the limbs for walking, plus reciprocal motions on opposite sides of the body or of the hindlimbs versus the forelimbs in four-legged animals.All these programs of the cord can be commanded into action by higher levels of motor control, or they can be inhibited while the higher levels take over control.Ref: Guyton; 13th edition; Chapter 57 Contributions of the Cerebellum and Basal Ganglia to Overall Motor Control
General physiology