Target height influences shoulder and elbow non-use after stroke during reaching with the hand : A brief communication

Background: During hand reaching movements in people with stroke, the coordination of trunk, shoulder, and elbow muscles changes as a function of target height. However, it is not known whether target height also influences non-use, defined as the difference between two coordinations aiming at the same target. Methods: Twenty-two individuals with stroke (> 1 month) completed the Proximal Arm Non-Use (PANU) test in two conditions: high target (80 cm) and low target (67 cm). Elbow, shoulder, and trunk use was recorded using motion capture. Results: Trunk compensation and non-use of the shoulder and elbow joints were found to depend on target height. Conclusions: Because trunk bending forward goes against the need to elevate the hand, a sufficiently low target is necessary to unmask the presence of shoulder-elbow non-use. We provide novel recommendations for assessing compensations and non-use during hand reaching. Clinical Trial: NCT04747587.