Preliminary Examination of the Ability of a New Wearable Device to Capture Functional Hand Activity After Stroke

BACKGROUND AND PURPOSE—A reliable measure of movement repetitions is required to assist in determining the optimal dose for maximizing upper limb recovery after stroke. This study investigated the ability of a new wearable device to capture reach-to-grasp repetitions in individuals with stroke. METHODS—Eight individuals with stroke wore an instrumented wrist bracelet while completing 12 upper limb activities. Participants completed 5 and 10 repetitions of each activity on 2 separate sessions (time 1 and time 2) and completed clinical assessments (Fugl-Meyer Upper Extremity Assessment and Action Research Arm Test). Mean reach-to-grasp counts (ie, hand counts) were compared across activities. Scaling properties were assessed by the ratio of 10 repetitions to 5 repetitions for the activities (ie, expected value of 2). Bland-Altman diagrams were used to examine agreement between time 1 and time 2 counts. RESULTS—The wrist bracelet averaged 0 to 0.6 hand counts per repetition for the arm-only and hand-only activities and averaged 1 to 2 counts per repetition of the reach-to-grasp activities. The mean ratio of 10 repetition to 5 repetition counts was ≈2 for all of the reach-to-grasp activities. Mean differences from time 1 to time 2 were