Effect of EMG-activated vibrotactile biofeedback on skill learning in children with genetic and acquired dystonia during practice of a point-to-point and a cyclic task.

Objective: Dystonia is a movement disorder causing involuntary muscle contractions and abnormal movements. Often, repeated practice does not lead to motor improvement in children with acquired dystonia, likely due to sensory deficits, which may contribute to their impairment. Therefore, improvement of sensory function might improve motor performance. In this study, we propose that an augmented vibrotactile biofeedback may improve motor learning in children with acquired dystonia, but not in children with genetic dystonia, who do not have associated sensory deficits. Design and participants: To test this hypothesis, we recorded muscle activity and kinematic recordings and computed outcome measures that represent motor skills, during practice of a point-to-point movement and trajectory-following task. We examined the effects of applying vibrotactile biofeedback on dystonic muscles, in healthy children and those with genetic and acquired dystonia. Results: The device significantly improved motor learning in children with acquired dystonia, in the cyclic task only, as evidenced by reduced error and improved task correlation index ( Conclusion: Our results show that the vibrotactile device can become an effective method of motor improvement only for cyclic and smooth tasks but not for point-to-point tasks in children with acquired dystonia.