Summary

This chapter deals with the neuronal mechanisms underlying impaired gait as a paradigm of movement disorder with the aim of first, a better understanding the underlying pathophysiology and second, the selection of an adequate treatment and rehabilitation. For the patient usually one of the first symptoms of a lesion within the central motor system represents the movement disorder, which is most characteristic during locomotion in patients with spasticity or Parkinson's disease. The clinical examination reveals changes in tendon tap reflexes and muscle tone, typical for an impairment of the motor system. However, there exists only a weak relationship between the physical signs obtained during the clinical examination in a passive motor condition and the impaired neuronal mechanisms being in operation during an active movement such as locomotion. By the recording and analysis of electrophysiological and biomechanical signals during a movement, the significance of impaired reflex behaviour or muscle tone and its contribution to the movement disorder can reliably be assessed. Consequently, an adequate treatment should not be restricted to the correction of an isolated clinical parameter but should be based on the pathophysiology and the mechanisms underlying the disorder of movement which impairs the patient. Actual therapy should be directed to take advantage of the plasticity of the central nervous system (CNS). In the future a combination of repair and functional training will further improve mobility of severely disabled patients.