Performance of static standing balance in children with spastic diplegic cerebral palsy under altered sensory environments

Seven children with spastic diplegic cerebral palsy and 14 age- and gender- matched nondisabled children participated in the present study for an inves tigation and comparison of their static standing balance under altered sens ory environments. The type of visual input (full, occluded, or sway referen ced vision) and the type of somatosensory input (fixed or compliant foot su pport) were varied factorially to give six sensory environments. Each parti cipant was tested barefooted for 30 s under all six conditions. A force pla tform collected the ground reaction force, from which standing balance was calculated as the sway area of the center of pressure. The results showed t hat when somatosensory information was reliable (fixed foot support), there was no significant difference in stance stability between the children wit h spastic diplegic cerebral palsy and their matched controls, and both type s of children were equally affected by the type of visual input. However, w hen somatosensory information was unreliable (compliant foot support), the difference in stance stability between the children with spastic diplegic c erebral palsy and their matched controls was significantly greater when the visual input was deprived (occluded) or unreliable (sway referenced) than when it was reliable. These results suggest that the children with spastic diplegic cerebral palsy may have difficulties in resolving intersensory con flicts for maintenance of standing balance, or the demands of motor control in sensory conflict conditions outweigh the motor ability of children with spastic diplegic cerebral palsy.