Document Type


Degree Name

Master of Science (MSc)




Faculty of Science

First Advisor

Dr. M. Cinelli

Advisor Role



On a daily basis modifications, based upon environmental demands and the capabilities of the individual, are made to the locomotor pattern to enable avoidance of undesirable landing areas (i.e. planar obstacles). Athletes and dancers have been suggested to have superior perception-action coupling compared to non-athletes, allowing them to perform various tasks at a greater speed without a loss of precision (Federici et al., 2005; Gerin-Lajoie et al. (2007). The current study assessed non-athletes, dancers, and field athletes to investigate whether training influences the maintenance of forward progression and stability in relation to alternate foot placement during planar obstacle avoidance. Eleven field athletes (22± 2.68 years) having recent/ current sport participation, 10 individuals (21.1± 1.1 years) with previous/current dance training, and 12 non-athletes (21.75± 1.54 years) with no participation in organized sport in >5 years were asked to walk to a goal (~13 m away) at a self-selected pace, avoiding any obstacle(s) when present (50% of trials; 15cm wide x 70cm long rectangles, projected ~8m from the start position). Obstacle conditions were: 1) Single obstacle appearance (SIN) where the obstacle (at N) appeared when the participant was 2 steps away from the first obstacle (N-2) ; 2) Double obstacle appearance was delayed (DDEL) until at N-2; and 3) Double obstacle appearance after participants reached steady state (i.e. ~3 steps from start)(DSS). All participants, regardless of training, stepped medially during SIN. Avoidance during double obstacle conditions was variable (i.e. medial-medial, medial-lateral, and lateral-medial). The variability of behaviour, computed as a coefficient of unalikeability (the proportion of possible comparisons which are unalike), had significant moderate positive correlations with the minimum Dynamic Stability Margin at N-1 for DSS and DDEL (r = 0.36; r = 0.44, respectively, p<0.001) and a significant weak positive relationship with ML COM variability (r = 0.28, p<0.05) during DDEL. To a degree, greater ML COM variability leads to avoidance behaviour that exploits forward progression more so than stability, as stepping medially perturbs the COM the least from its forward momentum but narrows the BOS creating instability that must be offset in the following step. Avoidance of planar obstacles at a comfortable walk lacked context specificity to dance or field sport training to elicit any behavioural differences.

Convocation Year


Convocation Season


Included in

Motor Control Commons