Stance balance control with orthoses in a group of children with spastic cerebral palsy

Although ankle-foot orthoses (AFOs) are frequently prescribed to correct sk eletal malalignment in children with spastic diplegia, their effect on stan ding balance abilities has not been documented. This study investigated bal ance differences related to the presence of pathology and orthotic conditio ns during conditions of unexpected stance perturbation by comparing four ch ildren aged between 3 1/2 and 15 years with spastic cerebral palsy and four control children matched for years of independent walking experience. Elec tromyographic and kinematic data were collected and compared between groups and in three orthotic conditions (no AFOs, solid AFOs, dynamic AFOs), Resu lts revealed that balance responses of children with spasticity mere charac terized by: increased coactivation of muscles as opposed to distal to proxi mal recruitment, decreased presence of upright posture in stance, increased use of 'on-toes' strategies, and different sway characteristics compared w ith the typically developing children. In both groups of children, the use of solid AFOs during perturbed stance resulted in: decreased activation of gastrocnemius muscles, disorganized muscle-response patterns, decreased use of ankle strategies, and increased joint angular velocities at the knee co mpared with conditions without AFOs or with dynamic AFOs, These preliminary results support the use of dynamic AFOs to correct skeletal malalignment i n children with spastic diplegia.