Kinetic analysis of planned gait termination in healthy subjects and patients with balance disorders.

We examined the stability and strategies used by balance impaired (vestibular hypofunction, VH: n=25; cerebellar damage, CB: n=20) patients and healthy (HE: n=52) controls during planned gait termination. Upper body strategies (during final stride and final step) were investigated using peak positive kinetic power (KP((+)): kinetic energy increasing), and peak negative kinetic power (KP((-)): kinetic energy decreasing) of the head-arms-trunk segment. Compared to HE controls (P<0.05): CB patients' medio-lateral KP((+)) and KP((-)) and were 53 and 71% higher during final stride, respectively; VH patients medio-lateral KP((+)) and KP((-)) was 78 and 57% higher during final step, respectively, and; during the final, standing stage VH patients were 32% less stable (from phase plane analysis) in the frontal plane. The excessive energy transfers in final stride for CB patients was likely due to poor eccentric muscle control when preparing for the stop. VH patients had difficulty controlling lateral stability during final step and once they had stopped walking, probably due to the lack of vestibular feedback regarding forward velocity changes. A better understanding of these abnormal movement patterns or compensatory strategies may assist in rehabilitation of patients with balance dysfunction.