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

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.

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).

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).

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.