Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Physiology and Localization of Gait
The bipedal gait is complex and depends on action of almost all parts of the nervous system. Gait is initiated in different ways depending on the purpose of the movement, whether intentional or reflexive. Gait generally originates in the cerebral cortex. Intentional initiation of gait is influenced by sensory inputs from multiple modalities. The resultant output of the sensory-motor cortex projects to the premotor and supplementary motor areas. These areas, in turn, generate the programmed movements for gait and feed those to corticobulbar and corticospinal centers for motor activation.
Cerebral output likely projects in part to the mesencephalic locomotor region that plays an important but poorly understood role in the coordination of gait, including walking and running. Output projects to motor systems especially for axial and proximal limb muscles. Although this is better understood for animals than humans, the function is thought to be related in human gait.
Gait is precise because of sensory feedback, both somatosensory and vestibular. These data are summed to modify the effort in a feedback manner. Did the intended movement occur, or is a correction needed? The cerebellum aids with this correction.
Types of Gait Abnormalities
Careful analysis of gait can identify the type of gait disorder. Here are some of the most important types of gait disorders.
Spastic gait
Bilateral corticospinal tract dysfunction at any level can produce a spastic gait. This is characterized by leg stiffness, narrow base, and often some circumduction on the forward swing to account for the difficulty with lifting the foot sufficiently.
Hemiplegic gait
Features of the spastic gait are seen but are unilateral, usually due to cerebral or brainstem lesion, although spinal lesions can be seen. The patient often leans away from the hemiplegic side to allow for circumduction of the affected leg.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here