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

No direct sensory testing was done for all participants, so the study cannot show that sensory deficits explained the response to biofeedback. Information on timing of brain injury, sensory deficit magnitude, and motor impairment severity was not consistently available and was not included in the model. Some task data were excluded for insufficient repetitions, contaminated data, or age matching, and the supplied text does not give the final analyzed number for each task. The protocol was run at three centers, but no formal validation study confirmed procedural equivalence across sites. The vibrotactile settings were not optimized, and the device increased co-contraction in some participants with acquired dystonia. The paper does not identify a single primary outcome, so the figure-8 result is one of several task-specific findings. The study tested performance on days 1 and 5 of each week, so it does not show whether the figure-8 benefit persisted after day 5.

Funding came from Ministero della Salute and the National Institutes of Health. The supplied text does not report a commercial sponsor or author conflict statement.

Do not conclude that vibrotactile feedback improves dystonia in general. It helped only the continuous figure-8 task in participants with acquired dystonia, did not improve the point-to-point spoon task, and did not help participants with genetic dystonia.