The Effects of Ipsilateral Forearm Movement and Contralateral Hand Grasp on the Spastic Hand Opened by Electrical Stimulation

The purpose of this study was to investigate the effects of ipsilateral arm movement and contralateral hand grasp on the spastic hand opened by open-loop electrical stimulation. The major problem of applying proper electrical stimulation is variable spasticity, the intensity of which changes with posture and movements of other parts of the body. Electrical stimulation was applied to extensor digitorum communis and ulnar nerve to open the affected hand. Different procedures were then used to assess the effects of moving the ipsilateral forearm and contracting the contralateral normal hand. Electrical stimulation opened the spastic hand in more than 95% of trials in all subjects, whether stimulation was applied before or after the movement of the forearm. Moving the ipsilateral forearm did have an effect on opening the hand, and making adjustment of stimulation intensities was necessary in all subjects. The stimulation opened the spastic hand during the contraction of the contralateral normal hand. Electrical stimulation could open the spastic hands most of the time, in the presence of ipsilateral forearm movement and contralateral normal hand contraction. If electrical stimulation was applied before the ipsilateral forearm was moved toward the target, stimulation intensities needed to be adjusted.