Gait analysis, isokinetic muscle strength measurement in patients with Parkinson's disease.

The aim of this study was to describe motor performance in Parkinson patients in relation to controls. Gait, concentric isometric and eccentric strength in the ankle dorsiflexors were investigated in 25 patients with Parkinson's disease and in 37 control subjects of the same age. In patients concentric torque was significantly lowered but, eccentric torque was significantly lowered in male patients only. Among controls a significant difference in strength was found between sexes. This was not found in the patient group. No correlation between strength tests and clinical ratings was found in the patient group. Patients walked with significantly lower maximum and ordinary velocity, compared with controls. At constant velocity, stride length was shorter, single support had a shorter duration. The duration for heel on to ball on in males was shorter, reflecting the flat foot strike of Parkinson patients. Single support and the duration of heel on to ball on correlated significantly to the clinical ratings in male but not in female patients. In the male group of patients there was a relation between concentric strength on the one hand and gait velocity, stride length and stride frequency on the other. Female patients generally had fewer symptoms and less deviation from their respective controls in the measurements. The comparatively simple neurophysiological tests presented here may be suitable for evaluation of patients with Parkinson's disease.