Non Amputees Lab Report

INTRODUCTION

It is difficult for lower-limb amputees to ascend and descend slopes without an articulating ankle joint. The healthy ankle is able to easily adapt to the changing slope and plantar- or dorsiflex accordingly. However, amputees typically have to make other compensatory actions in order to aid in the ascension and dissension of slopes. These compensations can cause long-term health problems and can be harmful and potentially lead to injuries. Results from this study on healthy subjects were compared to a study previously performed on amputees that quantified the effect of ankle range-of-motion on their biomechanics when walking on slopes [1]. The purpose of this follow-up study was to conduct an analogous experiment on non-amputees
All participants (4 male, 4 female, weight 154 ± 26 lbs) were compensated $10 for their participation. Subjects walked on a split-belt force-instrumented treadmill while we recorded ground reaction forces (GRFs). We did not collect motion capture data as to expedite the testing process. Before testing, subjects were fit to the correct size AirCast Boot. All subjects completed the control conditions first (walked with their tennis shoes on) at all 5 slopes. For the control conditions all subjects walked at a speed of 1.0 m/s. After subjects completed each of the control conditions, they walked at a self-selected speed with the AirCast Boot on at all slopes (7 subjects walked at 1.0 m/s, 1 subject walked at 0.9 m/s). All subjects were given a brief resting period between trials to minimize fatigue. Each of the locked ankle trials were collected after each subject was given an appropriate amount of time to acclimate to walking with the boot on (30 - 45 seconds). We focused on two main outcome measures: fore-aft GRFs and center of mass (COM) power. Because we did not collect motion capture data, we were not able to look at kinematics. However, GRFs and COM power are useful for assessing gait symmetry
2; Slope +9). A similar trend was observed for downhill walking: the locked ankle resulted in reduced negative peak power in early to mid-stance (Fig. 2; Slope -9). This gives us reason to believe that the locked ankle is not able to absorb as much energy upon weight acceptance when walking downhill, and it was not able to provide as much power at push-off when walking uphill. The locked ankle condition also lead to a reduced amount of negative work when walking downhill and a reduced amount of positive work when walking uphill, as compared to the control