Paradoxes in the Neurokinesiology of Spastic Gait

Overview

Spasticity is one of the most important problems in patients with central locomotor disorders. Spasticity cannot be separated from other symptoms with central locomotor impaierment - from motor symptoms, cognitive disorders, disorders of practice, visual spatial orientation to emotional, psychosocial problems etc. Also when evaluating and treating spasticity in the narrower sense we have to consider the phasically conditioned spasticity, the rate non-conditioned neurogenic spasticity (rigidity), changes of viscoelastic properties of the myofascial complex due mainly to alterations of connective tissue structures. All this is associated with hypotonia of some muscle groups. A certain muscle group can be hypotonic or hypertonic during different locomotor tasks and the distribution of the muscular tonus can then dramatically differ when tested during a static situation and during different stages of motor activity. Therefore it is from the practical aspect much more useful to evaluate spasticity in terms of the impaired motor programme and its implementation, in terms of disorders of temporospatial distribution of activation of muscles and motor units. When following the activity of an individual spastic muscle we are faced with the dissociation of the correlation between the degree of activation of the muscle and the development of its tension. With this the shift of biomechanical effectiveness ot the muscle beynd the optimal range is closely associated. In spastic muscle there is a higher EMG activity per unit ot power, moreover it is untavourably distributed in time and space. Advanced methods ot modern neurophysiology and in particular multimodal motion annalysis open a somewhat altered view on the tunction ot the neuromuscular complex under physiological and pathological conditions. Some results illustrate well and contirm empirical experience trom everyday practice with spastic patients. Other findings however cast doubt on accepted ideas. They show moreover that concepts ot classical analytical kinesiology such as muscular weakening, hypertonia, hypotonia, hypeactivity, hypoactivity etc. provide at least in spasticity doubfful intormation. Muscles typically considered as weakened may by their abnormal hyperactivity signiticantly distort the gait cycle in spastic patients and conversely muscles considered hyperactive may be in certain stages ot movement markedly inhibited. Two areas ot problems and tasks are apparent: First ot all - clinical application ot steadily expanding tacts assembled by modern methods ot locomotor analysis and integration ot these findings with physiotherapeutic empirical experience. Secondly - integration ot the analytical approach in kinesiotherapy with the overall view tocused not only on the actual locomotor task but also on actual objectives ot the rehabilitation process.

Key words:
spasticity, kinesiology, neurophysiology, physiotherapy, rehabilitation