Preliminary Measurements of Natural Yaw Angle of Forearm During Reaching Exercise for the Effective Robot-Mediated Upper Limb Rehabilitation

The ArmAssist, developed by Tecnalia, is a portable cost-effective upper limb rehabilitation platform for at-home tele-rehabilitation after a stroke and a reaching exercise is one of important trainings offered by the ArmAssist. From previous pilot study of the ArmAssist, it has been found that in the reaching exercise, the device should provide comfortable and natural orientation of the forearm for effective and safe rehabilitation. Hence, in this study, we present preliminary measurements of natural orientation of the forearm, specifically yaw angle that corresponds to the orientation of the device during the exercise. Two healthy subjects participated in the measurements using the ArmAssist platform and the results show that comfortable and natural yaw angle of the forearm during the reaching exercise varies with the position while anthropometric information of the subject such as arm length also has an influence on the angle. These findings imply that the forearm position and subject's limb information should be taken into account to find the proper orientation of the device.