Impact of suppressed tremor: Is suppression of proximal joints sufficient?

Recent progress in wearable technology has made exoskeleton-type therapy devices a potentially viable alternative solution for Parkinsonian tremor management. The target user group includes patients for whom current treatments have had no or minimal effect, or may cause major complications. So far, a number of tremor suppression devices have been developed. However, most of the studies and devices only considered the tremor in the wrist and elbow despite evidence that tremor is also present in the finger joints. The aim of this paper is to study the impact of suppressed tremor on the unrestricted joints, and to determine the importance of suppressing finger tremor in addition to the other most-studied joints. In this paper, tremor was analyzed using linear acceleration and electromyography (EMG) signals. The results show an increase in tremor magnitude in the unrestricted joints; however, EMG analysis did not show significant change in tremor muscle activity. This indicates that the increase in tremor motion may be the result of the propagation of tremor from one joint to another.