Analysis of 3-D Ultrasound of Calf Muscle Geometry in Children: Growth, Spasticity, Mechanisms and Treatment Children with spastic cerebral palsy

Children with spastic cerebral palsy (SCP) are often impaired in their gait as a result of a decreased range of motion (ROM) of their ankle joint. One of the most common treatments of the decreased ROM is injection of botulinum toxin A (BTX-A) into the spastic ankle plantar flexor muscles. The rationale behind this treatment is to temporarily decrease activity of the spastic muscles (by blocking motor endplates), therefore allowing an increase in ankle ROM. BTX-A treatment is usually followed by a period of serial casting of the ankle towards dorsal flexion to maintain an extended position of the plantar flexor muscles in an effort to stimulate longitudinal growth of the muscle fascicles and hence an increase in ankle dorsal flexion ROM. In the short term, ankle dorsal flexion is increased after such treatment. However, in the long-term, success of this integrated treatment is highly variable. To date, little is known about the mechanisms by which BTX-A and serial casting affect the ankle plantar flexor muscles in children with SCP. Such knowledge is required for improvement of the efficacy of treatment. The general aim of the studies of which this thesis is a part, is to investigate how ankle plantar flexor muscles are changed in children with SCP compared to typically developing (TD) peers and to investigate how such changes are affected by the integrated treatment of BTX-A and serial casting.