Effects of Robotic Exoskeleton Dynamics on Joint Recruitment in a Neurorehabilitation Context

Increasing research has been conducted into the use of robotic devices for neurorehabilitation. One advantage of these devices over traditional rehabilitation is the availability of measured data, which can be used to inform potential patient-specific protocol for recovery or simply to provide higher frequency feedback to the patients and therapists. It has previously been identified that such devices may have unplanned effects on the movement of patients. However, the exact nature of these effects are unknown, which makes the meaning of any measured data less clear. As such, this study investigates the effect of the mechanical dynamics of a robotic exoskeleton (ArmeoPower, Hocoma, Switzerland) on the movements of healthy subjects - particularly with respect to the movements of the shoulder, and joint utilisation. The study finds that the exoskeleton may encourage changes in shoulder movement in both magnitude and direction and changes in the joints recruited for the movement. Furthermore, the effects of the robot on joint utilisation are not consistent across reaching directions, however, the peak joint velocities are decreased across all joints and reaching directions.