Detecting Compensatory Trunk Movements in Stroke Survivors using a Wearable System

Abstract

Because of the redundancy in the human body, stroke survivors often use atypical compensatory movements, such as reaching with trunk motion to compensate for deficits in arm function. Prior studies have established that minimizing these compensatory movements during therapy result in improvements in arm function -- however, there has been little effort till date to monitor these compensatory movements during everyday activities outside of a lab environment. Here, we developed a wearable senor system that is capable of detecting compensatory trunk movements in a wide range of upper extremity activities. Participants with chronic stroke participated in the experiment, performing a range of activities with both the affected and unaffected arm, while wearing a 3-sensor wearable system, where each sensor consisted of an accelerometer and a gyroscope. Results showed that activities that involved elbow extension robustly elicited compensatory movements on the affected arm, and were detected with high accuracy by the wearable system. On the other hand, activities which did not require elbow extension did not elicit trunk compensation, and resulted in low classification accuracy. These results show the potential of using a wearable sensor system to detect compensatory movements in stroke survivors, which can be a critical tool for rehabilitation outside of the lab.