Lower limb extensor moments in children with spastic diplegic cerebral palsy

Two-dimensional B-mode ultrasound imaging and motion tracking were combined to generate three-dimensional reconstructions of the medial gastrocnemius. Architectural and morphological features of this muscle could be visualised. The length of the gastrocnemius belly was measured in normally (ND) developing children and in children with spastic diplegic cerebral palsy (SDCP) who had plantarflexion contractures. Using a random effects linear model we demonstrated that the gastrocnemius muscle bellies of children with SDCP were shorter than those of ND children (P=0.001) even when corrected for ankle position. The technique described could be used to evaluate muscular deformity before and after an intervention.