Proprioception and locomotor disorders

Advances in our understanding of movement control allow us to define more precisely the requirements for the rehabilitation of patients with movement disorders. Most purposeful, complex movements are programmed in the central nervous system (CNS) and adapted by proprioceptive feedback. The selection of and interaction between different sources of afferent input is task dependent. Simple stretch reflexes are thought to be involved primarily in the control of focal movement. For more complex motor behaviours such as locomotion, afferent input related to load and hip-joint position probably has an important role in the proprioceptive contribution to the activation pattern of the leg muscles. There is increasing evidence that movement disorders such as spasticity and Parkinson's disease involve the defective use of afferent input in combination with secondary compensatory processes. This has implications for therapy, which should be directed to take advantage of the plasticity of the CNS.