1. FOOT MECHANICS DURING WALKING WITH ADDED MASS.
1Nikolaos Papachatzis, 1Jeffrey M. Patterson, 1Kota Z. Takahashi
1 Department of Biomechanics, University of Nebraska, Omaha, NE, USA
web: cobre.unomaha.edu/ 68182
Biological Limbs and Assistive DEvices
INTRODUCTION
HYPOTHESES & METHODS
Humans must absorb/store and generate/return energy during locomotion.
Foot deformations are responsible for absorption and dissipation of energy during locomotion [1].
Research Question: What is the role of each foot segment in the context of the mechanical work production during loaded locomotion conditions?
Research Approach: We will measure how people modulate foot deformation mechanics (Figure1. distal to hindfoot) across a series of varying loads. .
We will quantify power/work contributions of the ankle-foot structures distal to hindfoot (Figure 1.) during walking with added body mass (0, % b.w.) by using a unified deformable segment analysis [2].
*x axis: Walking with added mass.
(0%, 15% & 30% of body weight)
Hypothesis #1
“Net work is preserved ”
Does the body adapt to maintain the same work/power profile as normal walking? 0%
15%
30%
Figure1. Ankle-foot structures
Distal to Hindfoot (i.e., Heel Pad, Arch, MTP):
Net work (j/kg)
Hypothesis #2
“Foot as an active power generator”
Do muscles behave actively?
(i.e. Generate more work)
Preliminary data:
Figure2. As you move proximally (i.e. MTP, Arch, Heel Pad, Ankle) each segment produces more positive work.
Do soft tissues absorb energy and dissipate it as a heat?
Hypothesis #3
“Soft tissues as a shock absorber ”
FUTURE APPLICATION
Robotics.
Prosthetic devices.
Foot Pathology
Rehabilitation & assistive devices.
Shoes.
Figure3. Flexible foot prototype performing adaptation to different surface to manually applied force[3].
REFERENCES
Kelly, LA, et al. J R Soc Interface 102, , 2015
Takahashi KZ, et al. J Biomech 45, , 2012.
Eckert & Ijspeert. Dynamic Walking 2016, Holly, Michigan, USA, 2016.
ACKNOWLEDGEMENDS
This work was supported by the NIH (P20GM and R15HD and the Center for Research in Human Movement Variability.