Graduation Date

Spring 5-8-2021

Document Type


Degree Name

Master of Science (MS)


Medical Sciences Interdepartmental Area

First Advisor

Ka-Chun (Joseph) Siu


When stepping over a single obstacle, despite of some spatiotemporal parameter changes, the impulse of the leading and trailing leg stays the same. This is considered an efficient obstacle avoidance strategy. However, research has shown that the strategy of multiple obstacles negotiation is different from a single obstacle crossing. Would this efficient strategy still exist during multiple obstacles negotiation? This study attempted to answer this question. Nineteen healthy young adults were recruited in this study. Each participant was required to complete 15 trials under 3 conditions: one-step, two-step, and three-step intervals. Data were collected for foot integrated pressure (FIP), walking velocity and spatiotemporal gait parameters of horizontal distance (HD) and vertical distance (VD). A three-way repeated measures ANOVA was used for analyses. Significant interactions were found on walking speed (p = 0.001), FIP (p < 0.0001), HD (p = 0.001), and VD (p < 0.0001). When the interval was two-step and three-step, a significantly increased FIP was found in the leading leg than the trailing leg at the second obstacle (p < 0.001, p < 0.001). This higher FIP was consistent with higher VD (p < 0.05, p < 0.05) and longer HD (p < 0.01, p < 0.01) of the leading leg. This study showed that the presence of the second obstacle changed the strategy of obstacle negotiation no matter whether the interval was one, two, or three steps. As suggested by FIP, in healthy young adults, the obstacle negotiation strategy was inefficient when stepping over the second obstacle.

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