Audiovisual cues can enhance sit-to-stand in patients with Parkinson's disease

We investigated whether preparatory signals, in the form of audiovisual cues, could enhance the performance of sit-to-stand (STS) in Parkinson's disease (PD) patients. Fifteen patients and fifteen control subjects similar in age, gender, weight, and height were examined. All subjects were instructed to carry out STS under self-initiated and cue-initiated conditions. A PEAK Motion Analysis System and two force plates were synchronized to record kinematic and kinetic data. In patients with PD, the addition of audiovisual cues was found to increase hip flexion and knee extension torques and decrease the time-to-peak joint torques, as well as increase peak horizontal and vertical velocities of the body center of mass and decrease the time taken to complete STS. Consequently, the performance of STS in these patients approached that of control subjects. In fact, during cue-initiated STS, no difference was found between the patient and control groups for the time-to-peak of all joint torques, the peak horizontal and vertical velocities, and the time taken to complete STS. Our findings thus demonstrated that audiovisual cues were effective in enhancing STS in patients with PD. These feed-forward signals could have enhanced the defective motor preparatory phase, thus leading to improved performance of the STS task. These findings provide a scientific basis for the use of audiovisual signals to enhance STS performance in patients with PD. (C) 2004 Movement Disorder Society.