We studied the influence of dopaminergic medication on the duration of standing up, static posture and gait in five patients with Parkinson's disease (Hoehn and Yahr stage 1.5 to 3) and four healthy controls, using an optoelectronic camera system. Duration of standing up was prolonged in patients, while static posture and gait were largely unaffected. The prolonged duration of standing up was corrected by dopaminergic medication. These results suggest that an increased duration of standing up is a relatively early and dopa-sensitive abnormality in Parkinson's disease. (C) 1997 Elsevier Science B.V.