The speed of sit-to-stand can be modulated in Parkinson's disease

Objective: To evaluate whether Parkinsonian patients could modify the speed of a sit-to-stand (STS) task to the same extent as that of healthy subjects. Methods: Twenty Parkinsonian patients and 20 control subjects were instructed to stand up at a natural and fast speed. Kinematic data and kinetic data were recorded. Results: Parkinsonian patients were significantly slower than healthy individuals during STS at a natural speed. When required to perform STS task at a fast speed, these patients could increase both peak horizontal and vertical velocities of the task, by significantly increasing hip and ankle dorsiflexion torques and the rate of torque production, just as the control subjects did. In fact, no difference was found for the percentage changes in both peak velocities and movement time between the two groups, though similar between-group differences during STS at a natural speed still existed at a fast speed. Conclusions: Parkinsonian patients had problems in generating adequate lower limb joint torques and in the rate of torque production when performing STS at a natural speed. However, these patients were capable of increasing the speed of their STS with the same percentage changes as those of healthy subjects. Significance: The capability of Parkinsonian patients for increasing movement speed gives new insights to rehabilitation strategy.