Background: Neurorehabilitation studies suggest that manipulation of error signals during practice can stimulate improvement in coordination after stroke.
Objective: To test visual display and robotic technology that delivers augmented error signals during training, in participants with stroke.
Methods: A total of 26 participants with chronic hemiparesis were trained with haptic (via robot-rendered forces) and graphic (via a virtual environment) distortions to amplify upper-extremity (UE) tracking error. In a randomized crossover design, the intervention was compared with an equivalent amount of practice without error augmentation (EA). Interventions involved three 45-minute sessions per week for 2 weeks, then 1 week of no treatment, and then 2 additional weeks of the alternate treatment. A therapist provided a visual cursor using a tracking device, and participants were instructed to match it with their hand. Haptic and visual EA was used with blinding of participant, therapist, technician-operator, and evaluator. Clinical measures of impairment were obtained at the beginning and end of each 2-week treatment phase as well as at 1 week and at 45 days after the last treatment.
Results: Outcomes showed a small, but significant benefit to EA training over simple repetitive practice, with a mean 2-week improvement in Fugl-Meyer UE motor score of 2.08 and Wolf Motor Function Test of timed tasks of 1.48 s.
Conclusions: This interactive technology may improve UE motor recovery of stroke-related hemiparesis.
Keywords: error augmentation; haptic technology; physical therapy; robotics; stroke rehabilitation; upper extremity.