Comparison of gait and architecture of the medial gastrocnemius in developmentally delayed children with different muscle tone: A preliminary pilot study

Background: Muscle tone alteration reduces gait and motor function in children with developmental delays. We aimed to determine differences in gait and structure of the medial gastrocnemius muscle between typically developing children and children with developmental delays with different muscle tone. Methods: Forty-nine participants were divided into typically developing children (n = 22), children with spastic hemiplegia (n = 6), children with spastic diplegia (n = 9), and children with central hypotonia (n = 12). A wearable gait analysis system was used to measure spatiotemporal variables and pelvic movement, and ultrasonography was used to measure the pennation angle, thickness, and fascicle length of the medial gastrocnemius. Finding: Children with spastic hemiplegia had significantly smaller total symmetric index and pelvic tilt symmetric index than typically developing children (P < 0.050). Children with spastic diplegia had smaller pen- nation angle than typically developing children (P < 0.050), and children with central hypotonia had lower velocity than typically developing children (P < 0.050). Children with spastic diplegia had a greater pelvic rotation range than children with central hypotonia (P < 0.050). Interpretation: This study helps to understand gait and muscle structure in central hypotonia and spastic cerebral palsy.