part of the figure shows the performance of the three groups under normal support surface
conditions (platform level and not moving) with eyes open, closed, and with eyes open in
a visual surround that moved with their sway. The right-hand part of the figure shows the
performance of the groups when the support surface was moving with their sway (labelled
stabilised support surface). You can see that the sway values for the children with ataxia
were greater than those for the typically developing children and the children with unilateral
spastic CP for all conditions. As shown by the stars, one of the three children with ataxia
lost balance under the stabilised surface condition with eyes closed, and two of the children
lost balance when standing on the stabilised surface in the visual surround that was
‘stabilised’ (moving with their sway). In addition, one child with unilateral spastic CP also
lost balance in this last condition, while no typically developing children had this problem.
These results suggest that these children have difficulty orienting to sensory environments
in which two of the three sensory cues (vision and somatosensation) are either distorted or
absent, and thus require a reliance on vestibular inputs alone.