Advisor Information
Dr. Kota Z Takahashi
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
2-3-2018 12:30 PM
End Date
2-3-2018 1:45 PM
Abstract
The ankle and foot system is a combination of flexible and adaptable structures. which are analogous to a spring that absorbs/stores and generates/returns mechanical energy during locomotion [1]. Studies have shown that the foot muscles are able to modulate arch compression during static loading conditions [2]. The purpose of this study was to determine how walking with varying levels of added mass affect the combined functional behavior of the foot. We hypothesized that the foot structures would increase the amount of dissipated/absorbed energy when walking with added mass. Eighteen healthy, young participants completed barefoot walking in three randomized loading conditions (0, +15, and +30% of added body mass). The walking speed was targeted at 1.25 m/s (2.8 mph). The mechanical power of the foot during the over-ground trials was quantified using a unified deformable segment analysis by modeling all structures distal to the calcaneus as a deforming body [1]. We quantified the negative and positive mechanical work over stance, by integrating the positive and negative portions of the mechanical power data. Walking with added mass had a significant effect on the magnitude of positive work (p < 0.001), including a 19% increase between 0 and +30% added mass conditions (p < 0.001). There was no significant effect of added mass on negative work (p = 0.055) and on net work (p = 0.402) (Figure 1). Experimental results failed to support our initial hypothesis, as the foot increased the magnitude of positive work, and preserved similar amounts of net negative work (i.e., energy dissipated/absorbed) across varying levels of added mass conditions. Overall, the foot appears to have similar characteristics of a shock absorber- spring complex.
FOOT STRUCUTRES INCREASED POSITIVE MECHANICAL WORK DURING LOADED WALKING.
Dr. C.C. and Mabel L. Criss Library
The ankle and foot system is a combination of flexible and adaptable structures. which are analogous to a spring that absorbs/stores and generates/returns mechanical energy during locomotion [1]. Studies have shown that the foot muscles are able to modulate arch compression during static loading conditions [2]. The purpose of this study was to determine how walking with varying levels of added mass affect the combined functional behavior of the foot. We hypothesized that the foot structures would increase the amount of dissipated/absorbed energy when walking with added mass. Eighteen healthy, young participants completed barefoot walking in three randomized loading conditions (0, +15, and +30% of added body mass). The walking speed was targeted at 1.25 m/s (2.8 mph). The mechanical power of the foot during the over-ground trials was quantified using a unified deformable segment analysis by modeling all structures distal to the calcaneus as a deforming body [1]. We quantified the negative and positive mechanical work over stance, by integrating the positive and negative portions of the mechanical power data. Walking with added mass had a significant effect on the magnitude of positive work (p < 0.001), including a 19% increase between 0 and +30% added mass conditions (p < 0.001). There was no significant effect of added mass on negative work (p = 0.055) and on net work (p = 0.402) (Figure 1). Experimental results failed to support our initial hypothesis, as the foot increased the magnitude of positive work, and preserved similar amounts of net negative work (i.e., energy dissipated/absorbed) across varying levels of added mass conditions. Overall, the foot appears to have similar characteristics of a shock absorber- spring complex.
Additional Information (Optional)
[1] Takahashi KZ, et al. Scientific Reports, 7(1), 15404, 2017
[2] Kelly, LA, et al. J R Soc Interface 102, 20141076, 2015