Postural control in strabismic children versus non strabismic age-matched children.

BACKGROUND: Several studies have shown that achieving a dual task modifies postural control; however, their results are conflicting. The goal of the present study is to compare the effect of a simple task (eye fixation) to the effect of a dual task (saccadic eye movements) on postural balance in strabismic and in non strabismic children.
METHODS: Postural stability was recorded with a platform (Techno Concept©) in ten strabismic children aged from 5.4 to 13.8 years (mean age: 8.8 ± 2.5 years). Data were compared to that of ten age-matched non strabismic control children. We analyzed the surface area, the length and the mean speed of the center of pressure (CoP).
RESULTS: Strabismic children are more instable than control children. The surface (340 mm(2)), the length (402 mm) and the mean speed (16 mm/s) of the CoP are significantly higher in strabismic children than in control children (160 mm(2), 280 mm and 11 mm/s, respectively). In addition, both strabismic and control children have a better postural control during saccades than during a fixation task. Surface, length and mean speed of the CoP are significantly reduced during the saccade task (214 mm(2), 306 mm and 12.5 mm/s, respectively) than during the fixation task (285 mm(2), 376 mm and 14.8 mm/s, respectively).
CONCLUSIONS: Abnormal postural control in strabismic children could be due to their visual deficits. The postural improvement observed in a dual task (saccades) vs. a simple task (fixation) might be due to the fact that postural control becomes more automatic during saccadic eye movements.