The determinants of obstacle avoidance strategies in children

The ability to steer in a cluttered environment and to make appropriate gait adaptations to avoid collisions is imperative to achieve safe locomotion throughout the environment. Minimal research has compared obstacle circumvention strategies between children at different stages of motor development. The current study aimed to determine the obstacle avoidance strategies employed by both 6-8 year old (N=12) and 10-12 year old (N=11) children when circumventing a vertically-oriented obstacle during goal-directed locomotion. Children were instructed to walk along a 9m path towards a goal (that was either visible or non-visible) and avoid a pole placed 5m along the path, which was either 20cm left of the midline of the goal, in-line with the goal, or 20cm to the right of the midline. In order to quantify the objectives, the COM position in both the medial/lateral and the anterior/posterior directions was calculated at each frame. Children were shown to avoid in the direction that afforded more space to their travel path (F(1.47, 30.84)=17.64, p<.01). In addition, children were shown to produce a smaller safety margin when the goal was in the centre position, than when it was to the left or the right (F(2,20)=17.04, p<.01). Children's time to contact the variable was consistent among the variables measured. The findings from this study suggest that children are able to successfully perceive their environment and that children rely heavily on visual information. Additionally, children complete obstacle avoidance prior to goal acquisition, rather than performing the task as a global entity.