Graduation Date

Spring 5-8-2021

Document Type


Degree Name

Master of Science (MS)


Medical Sciences Interdepartmental Area

First Advisor

Ka-Chun Siu

Second Advisor

Kathleen G. Volkman

Third Advisor

Bradley D. Dexter


Human locomotion is adaptive in any external environment or different terrains, which has been widely investigated. For example, people can walk at different walking speeds in each leg on a split-belt treadmill. However, human locomotor behaviors are passively adapted during the split-belt treadmill walking. Therefore, the knowledge of how humans actively adjust the flexibility of locomotion is limited by using the split-belt treadmill. To address this gap, this study investigated the flexibility of locomotion by using a 4-lb ankle weight on the dominant leg to induce the asymmetric walking pattern when walking on the inclined, declined, and level treadmill. Twenty healthy young participants were recruited for this study. Six conditions (walking on the level, 15% grade of the inclined treadmill, 15% of the declined treadmill with/without wearing 4-lb loading on the dominant leg) were randomly assigned to participants. Step length symmetry (SLS) and step time symmetry (STS) were dependent variables. There was a significant interaction between the effect of unilateral limb loading and the effect of inclinations on SLS and STS (p < 0.0001). The post hoc comparisons indicated that unilateral limb loading caused an asymmetric walking pattern when walking on the level and the inclined treadmill but not on the declined treadmill. This phenomenon could be explained by increased levels of active control when walking on the declined treadmill to eliminate the effect of unilateral limb loading by reducing the step length and step time. The current result illustrates the possibility of using the declined treadmill to readjust the symmetric walking pattern in people who walk asymmetrically.