The Muscle in Cerebral Palsy; Sarcomere Length in Vivo and Microscopic Characterization of Biopsies.

Cerebral palsy (CP) is a motor impairment due to a brain malformation or a brain lesion before the age of two. Spasticity, hypertonus in flexor muscles, dyscoordination and an impaired sensorimotor control are cardinal symptoms. The brain lesion is non-progressive, but the flexor muscles of the limbs will during adolescence become relatively shorter and shorter (contracted), forcing the joints into a progressively flexed position. This will worsen the positions of already paretic and malfunctioning arms and legs. Due to bending forces across the joints, bony malformations will occur, worsening the function even further. Currently, the initial treatment of choice is the use of braces, which diminishes the shortening somewhat, but eventually lengthenings of tendons and release of aponeuroses around the muscles often is needed, and transfers of wrist flexors to wrist extensors may improve w