Does visual error augmentation offer advantages during bimanual therapy in individuals poststroke? A randomized controlled trial

Objective: Reaching training with error augmentation has recently shown great promise for enhancing bimanual therapy training, using both robotic force feedback (haptics) and visually distorted display elements (graphics) to amplify motor learning. Methods: In this two-arm, randomized controlled trial, we explored the effect of visual error augmentation alone by visually shifting the paretic limb’s cursor in the direction of error. We invited 38 chronic (>8 months postinjury) stroke survivors to practice bimanual reaching for approximately 40 min, 3 days per week for 3 weeks. Results: The arm motor section of the Fugl–Meyer score (maximum score, 66 points) increased by an average of 2.2 and was retained at an average of 1.5 at a follow-up evaluation 7–9 weeks (approximately 2 months) later. For chronic stroke survivors, an improvement of ≥5.2 in the arm motor section of the Fugl–Meyer score is considered a clinically meaningful increase. No superiority was detected due to the error augmentation treatment, but other measures of composite abilities (range of motion, bimanual symmetry, and movement time) showed improvements favoring error augmentation. Conclusions: Although removing robotic forces led to smaller gains than those reported previously, such touch-free bimanual therapy may prove to be an effective inexpensive automated rehabilitation tool for wider accessibility in therapeutic interventions. Trial registration: This study has been registered at ClinicalTrials.gov (ID#NCT03300141).