Lower limb muscle volumes in bilateral spastic cerebral palsy

Aim: Muscle weakness is a feature of individuals with spastic cerebral palsy (SCP) but there are few reports in the literature of muscle volume in this group. This study compares muscle volumes in adolescents and young adults with SCP with those of their typically developing (TD) peers. Design: Measurements of the volumes of nine major lower limb muscles in 19 independently ambulant subjects with SCP (mean age 14.2 years (sd 2.7), 11 male, GMFCS I (n = 5); GMFCS II (n = 14)), 19 TD subjects (mean age 16.5 years (sd 3.0), 11 male) were made using magnetic resonance imaging. Results: Lower limb muscles were smaller in the SCP group (p ⩽ 0.023 in all muscles) than the TD group with the exception of the vastii (lateralis + intermedius; p = 0.868) and gluteus maximus (p = 0.056). Average muscle volume deficit was 27.9%. Muscle volume deficits were significantly greater for distal muscles than proximal muscles (p < 0.001). Conclusions: Reduced muscle size in adolescence and the natural history of sarcopenia in adulthood may contribute to the early loss of mobility of adults with SCP.