Clinical assessment of forearm pronation/supination torque in stroke patients

The main goal of this study was to quantify the pronation/supination torque of the forearm during the planar circular motion of the whole upper limb. One of the synergy patterns of the stroke patients was the involumtary pronation/supination of forearm while they were moving their elbow joints. A new torque measurement system was designed and installed on a previously built shoulder-elbow rehabilitation robot. The robot could apply either resistant or assistant force on the subject's wrist when the upper limb was performing a circular movement. The pronation/supination torque and the trajectory of tracking movement were recorded during the treatment procedure, and the pronation and supination torque of forearm were analyzed offline. The experimental results revealed that the forearm pronation/supination torque of stroke subjects could be detected and quantified while the subjects were performing the tracking movement on the transverse plane. The able-bodied subjects provoked less forearm pronation/supination torque during similar movements.