Spatial and temporal analyses of posture in strabismic children

To analyse postural performances of strabismic children, both in the spatial and the temporal domains, by wavelet transformation, comparing both stable and unstable situations. Twenty-six strabismic children aged from 4 to 11 years old and 26 age-matched normal children participated in the study. Postural performances were evaluated using the FramiralA (R) platform. Posture was recorded in the following conditions: eyes open fixating a target and eyes closed on stable and unstable platforms. For both strabismic and non-strabismic children, the surface and the mean velocity of the center of pressure (CoP) were significantly larger in the eyes closed on unstable platform condition, but this was much more pronounced in case of strabismus. Spectral power index and cancelling time were also found to be altered in strabismic children compared to non-strabismic children. This data demonstrates poor postural stability for both groups on an unstable platform with the eyes closed. However, strabismic children had significantly worse performance than non-strabismic children. Strabismic children also engage more energy to stabilize their posture by using visuo-vestibular sensory inputs to compensate their altered vision due to strabismus, in comparison to non-strabismic children.