RESEARCH REPORT POSTER DISPLAY

SURFACE EMG AS A TREATMENT TOOL TO GUIDE INTERVENTION TECHNIQUES IN CHILDREN WITH CEREBRAL PALSY. McCoy S¹, Bodenhamer M¹, Schultz M¹, Anderson B¹, Embrey D²; ¹University of Puget Sound, Tacoma, WA, USA. ²Good Samaritan Children’s Therapy Unit, Puyallup, WA, USA

PURPOSE: The purpose was to evaluate the use of surface electromyography (sEMG) as a quantitative decision making tool to guide selection of practice activities for children with cerebral palsy (CP). RELEVANCE: Surface EMG can be used to measure muscle co-activation patterns. Excessive use of co-activation may lead to inefficient movements and increases in energy expenditure in children with CP. Practicing activities which show decreased muscle co-activation as identified via sEMG may encourage motor learning of more efficient coordination patterns for both the practiced and other motor activities. PARTICIPANTS: Three children who were currently receiving physical therapy intervention, two boys, age 6 and 9 years, and one girl age 10 years, with spastic diplegic CP and a Gross Motor Function Classification System of Level II participated. METHODS: An AB single subject research design was used. Prior to the baseline phase (A), surface electrodes were placed on four lower extremity muscles to measure co-activation during several mobility activities appropriate for each child, such as walking backwards, running etc.. Using a measure of co-activation index, the two activities with the least amount of co-activation were identified as the “practice activities” and one activity with the greatest amount of co-activation was identified as the “target activity”. During baseline phase, measurements of the time to complete the practice and target activities across standardized distances, as well as the Standardized Walking Obstacle Course (SWOC) were collected. The introduction of the intervention (B) phase was based on achieving stability in the baseline data. During the B phase, the two “practice activities” were practiced using massed and random parameters within the therapy session and at home for 8 weeks as part of the child’s regular physical therapy intervention. Weekly measurements of the same variables were made. The SWOC and target activities were tested to determine transfer of the improved motor efficiency expected in the practiced activities. ANALYSIS: The SWOC, practice activities, and target activity times were graphed and visually analyzed with the assistance of celeration lines to determine the effect of the intervention on motor efficiency. RESULTS: One subject (9 year-old boy) showed improvements in both practice activities as well as the target task and SWOC test. These results suggest that improvements made in the practice tasks were transferred to the target task and SWOC implying motor learning and possible coordination changes. Results of the other two subjects were mixed, showing the improvement expected in some of the measurements, but analysis was complicated by several B phase missing data points and an unanticipated change in one child’s regular therapy program. CONCLUSIONS: Practicing activities selected through sEMG co-activation analysis to encourage motor learning may assist to change a child’s overall motor efficiency. The results of this study provide interesting results that should guide further investigation. IMPLICATIONS: The findings from this study provide beginning evidence to indicate that sEMG may be used as a quantitative tool to help pediatric physical therapists develop intervention plans that more effectively change motor efficiency. Further evidence is warranted to fully support this approach. KEYWORDS: cerebral palsy, motor learning, surface electromyography. FUNDING ACKNOWLEDGEMENTS: University of Puget Sound, Tacoma, WA, USA, Enrichment Committee Student research Awards #SR0448. CONTACT: swestcott@ups.edu

ETHICS COMMITTEE: University of Puget Sound Internal Review Board Committee, Tacoma, WA, USA