Measurements of the centre of pressure of individual legs reveal new characteristics of reduced anticipatory postural adjustments during gait initiation in patients with post-stroke hemiplegia

Abstract

Objectives: To determine whether individual measurements of the centre of pressure for the stance and stepping legs can reveal new characteristics of reduced anticipatory postural adjustments during gait initiation in poststroke hemiplegic patients. Methods: Subjects included 30 stroke patients and 10 healthy agematched controls. The acceleration of the trunk, and the centre of pressure of each leg, were measured during gait initiation, 3 times each with the paretic and nonparetic legs leading. Anticipatory postural adjustments were characterized using trunk acceleration and centre of pressure displacement data. Results: Latency of the posterior displacement peak of the paretic leg centre of pressure with either the paretic or non-paretic leg leading was significantly longer in stroke patients compared with controls, and was also longer than that of the nonparetic leg. The magnitude of the posterior displacement peak of the paretic leg centre of pressure was smaller than that of the nonparetic leg. Peak latency of the paretic stepping leg centre of pressure correlated with the clinical measures of motor dysfunction, postural balance, and gait ability. Conclusion: Measurements of the latency and magnitude of centre of pressure displacement peak individually for the paretic and nonparetic legs can help elucidate the mechanism behind reduced anticipatory postural adjustments. This information will be useful in designing new treatment strategies for stroke patients.