Development of an Active Upper Limb Orthosis Controlled by EMG with Upper Arm Rotation

An active upper limb orthosis was developed for patients who cannot move their upper limb. The system has two independent motors that allow flexion and extension of the shoulder and elbow, and in addition, rotation of the upper arm. By incorporating arm rotation, activities of daily living (ADLs) are improved. If the patient is able to move their wrist as in Erb's paralysis, electromyogram (EMG) generated by the movement of the wrist is processed by an original system and used to control the orthosis. Evaluations were performed on moving range of orthosis by a healthy subject and on ADL tasks by an Erb's palsy subject. There were tasks that the subject could not complete because of lack of function or range of motion of orthosis. However, tasks that require use of two arms, which the subject could not complete previously, were completed using the orthosis.