Fig. 1

Study design. A Information workflow from wearable devices and smartphone app to data post-processing for sensor data synchronization and interpretation. Left: the devices record motion data and communicate via a Bluetooth connection with a custom application to generate exercise cues. Center: accelerometer data from both limbs is synchronized and processed to obtain motion profiles as a function of time. Right: motion data is further processed to obtain objective measures of bilateral arm use. B Study timeline. C Cued exercises ranging from easiest (Tapping; top) to more challenging (Independent; bottom). Tap: when cued, the participant was to use their LA arm and hand to tap the wearable device on their MA limb’s wrist. Assist: when cued, the participant was to grasp the wrist of their MA arm with their LA hand and to use the LA limb to flex and then extend their MA elbow. Independent: when cued, the participant was to perform independent flexion–extension movements of their MA arm