Neural and musculoskeletal contributions to the development of stance balance control in typical children and in children with cerebral palsy

Abstract

Studies on the development of automatic postural responses in both typically developing children and children with cerebral palsy were performed. With the appearance of 'pull-to-stand' behavior, typically developing children first began to show muscle responses to platform movements in mainly the ankle muscles. With increased development, additional agonist muscles were added to the response pattern and a consistent distal to proximal sequence began to emerge. Well-organized responses were seen with the onset of independent stance and walking, along with the reduction of antagonist muscle co-activation. The older children with cerebral palsy who were pre-walkers had immature muscle activation patterns like those seen in the typically developing children at the pull-to-stand stage of development. These included disorganized muscle responses and increased frequency of coactivation of both proximal-distal and agonist-antagonist muscles. In order to determine if musculoskeletal constraints contributed to these response patterns, normal children were asked to stand in a crouched posture similar to that of children with CP. This caused postural muscle response patterns to more closely approximate those of children with spastic diplegia.