RELIABILITY OF LEG MUSCLE SIZE AND QUALITY ESTIMATES FROM ULTRASOUND IN CHILDREN WITH CEREBRAL PALSY By SUZANNE ELIZIBETH VOGLER

PURPOSE: The aim of this study was to determine if ultrasound imaging can provide reliable estimates of the size and quality of leg muscles in children with spastic cerebral palsy (CP). METHODS: Ambulatory children with spastic CP (n = 7) were recruited. Cross-sectional area (CSA) and echo intensity (EI) of the gastrocnemius at 25, 50 and 75 % of muscle belly length and of the TA at 20, 40 and 60 % of tibia length were assessed (n = 14 legs). The tests were repeated four weeks later. RESULTS: There were no test-retest differences in CSA or EI estimates in the gastrocnemius or the TA at specific sites, except for TA CSA at the 20 % site, which was lower at the repeat test (p = 0.023). There were also no test-retest differences (p > 0.05) in the average CSA and EI of the different sites for the gastrocnemius and the TA). CONCLUSION: The reliability of most ultrasound day-to-day estimates of CSA and EI for the gastrocnemius and TA are considered good to excellent in children with spastic CP.

INDEX WORDS: cerebral palsy, ultrasound, muscle cross-sectional area, muscle volume, echo intensity, muscle belly