Finger Extensor Facilitation Training Device “iPARKO”: Analysis of increased muscle activity in a hemiplegic person

Applying an external force to a person's hyperextended fingertip produces electrical activity of the extensor digitorum muscle even when the hand is not opened by the person. Based on this, a finger extensor facilitation technique has been developed for hemiplegic patients who cannot open the paralyzed hand by themselves. In this study, we developed a finger extensor facilitation training device named “iPARKO” that imitates this technique. We examined the factors that promote activities in the extensor digitorum muscle by conducting active training using iPARKO. Experiments were conducted on a healthy person and a hemiplegic person. It was found that active training using iPARKO leads to activities in the extensor digitorum muscle even in a hemiplegic person who cannot open their hand. In addition, it was found that a hemiplegic person can increase muscle activity by pressing their hand movement and utilizing electromyography biofeedback. The hand movement was clarified as follows: the hemiplegic person pressed the hand against the moving part of the device and pushed the fingertip further into it as a voluntary movement to increase the amount of muscle activity.