Can spatial filtering separate voluntary and involuntary components in children with dyskinetic cerebral palsy?

• Published in: PloS one Vol. 16; no. 4; p. e0250001
• Main Authors: Borish, Cassie N., Bertucco, Matteo, Berger, Denise J., d’Avella, Andrea, Sanger, Terence D.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.04.2021; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Care and treatment; Cerebral palsy; Channel capacity; Children; Children & youth; Contraction; Controllability; Demographic aspects; Dystonia; Engineering and Technology; Health aspects; Human-computer interface; Hypotheses; Information theory; Interfaces; Laboratories; Medicine and Health Sciences; Muscles; Noise; Paralysis; People and Places; Physiological aspects; Physiology; Research and Analysis Methods; Spatial filtering; Spinal cord; Stability; Touch screens; United States; United States > US; Italy; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0250001

The design of myocontrolled devices faces particular challenges in children with dyskinetic cerebral palsy because the electromyographic signal for control contains both voluntary and involuntary components. We hypothesized that voluntary and involuntary components of movements would be uncorrelated and thus detectable as different synergistic patterns of muscle activity, and that removal of the involuntary components would improve online EMG-based control. Therefore, we performed a synergy-based decomposition of EMG-guided movements, and evaluated which components were most controllable using a Fitts’ Law task. Similarly, we also tested which muscles were most controllable. We then tested whether removing the uncontrollable components or muscles improved overall function in terms of movement time, success rate, and throughput. We found that removal of less controllable components or muscles did not improve EMG control performance, and in many cases worsened performance. These results suggest that abnormal movement in dyskinetic CP is consistent with a pervasive distortion of voluntary movement rather than a superposition of separable voluntary and involuntary components of movement.