Longitudinal characterization of medial gastrocnemius muscle growth deficits throughout childhood in spastic cerebral palsy

A longitudinal study analyzed muscle growth deficits in children with spastic cerebral palsy (CP) compared to typically developing peers throughout childhood. Researchers measured medial gastrocnemius muscle length, tendon length, muscle-tendon unit length, cross-sectional area, volume, and echo-intensity using 3D-freehand ultrasound in 116 CP children and 236 TD children.

The data, adjusted for body size, showed distinct muscle value changes with age and differences between CP and TD groups. At one year, GMFCS-III children exhibited larger deficits in muscle belly and muscle-tendon unit length, as well as cross-sectional area and muscle volume, compared to GMFCS-I and II groups (p < 0.05). Muscle deficits continued to increase with age, except for muscle belly in GMFCS-III, and muscle-tendon unit length and echo-intensity in GMFCS-I and II.

Transverse-related parameters (cross-sectional area) and combined parameters (muscle volume) were more affected than axial-related ones (muscle belly, tendon length, muscle-tendon unit length). Early support for muscle growth becomes crucial around 2-3 years in GMFCS-I and II, while in GMFCS-III, it is important starting at one year of age.