A Comparison Between Reaching Distance and Work Area for Measuring the Impact of Flexion Synergy on Reaching Function in Chronic Moderate to Severe Hemiparetic Stroke

Two primary mechatronic protocols have been deployed across several studies for measuring the impact of flexion synergy (loss of independent joint control) on reaching function. The measurement of reaching work area and reaching distance were both conducted as part of a previous clinical trial with the latter being the study's primary outcome. While evidence exists supporting the reliability and validity of reaching work area, it may be time-inefficient and/or too fatiguing to be viable in clinical practice. Reaching distance was therefore employed in the clinical trial as the primary outcome as a shortened method despite established validity. In this retrospective study, pre- and post-intervention data of both metrics from the clinical trial are used to evaluate concurrent validity of the reaching distance metric and to compare its responsiveness to change with that of reaching work area.