Award Date

5-1-2019

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

First Committee Member

Mohamed B. Trabia

Second Committee Member

Janet S. Dufek

Third Committee Member

Jaeyun Moon

Fourth Committee Member

Woosoon Yim

Fifth Committee Member

Brendan O'Toole

Sixth Committee Member

Julia Freedman Silvernail

Number of Pages

184

Abstract

Introduction: The mechanical characteristics of the plantar tissues during walking is not well understood as most of the current research focuses on testing specific plantar regions in cadavers or while the feet of the participants are raised. In this work, it is hypothesized that a viscoelastic geometric ellipsoid model used to assess multiple structures of the foot would be accurate and robust. This model would be participant-specific and applicable to the entire stance phase of gait.

Methods: The proposed viscoelastic ellipsoid model would represent several key anatomical areas: Heel, Posterior Midfoot, Anterior Midfoot, Metatarsals 1-2, Metatarsals 3-5, Toe 1, Toe 2, and Toes 3-5. The ellipsoid model required measurement of force and contact area simultaneously. This was done using pressure-measuring insoles (Medilogic ®, Schönefeld, Germany), worn by multiple, college-aged participants. The insole force and area data were used to optimize the model for each participant as the material properties and geometry of each participant’s foot will differ.

Results: The results of the model application was able to show that the ellipsoid model was fairly successful in producing the ground reaction force during walking. Further, the ellipsoid model was able to characterize stiffness and damping results, that were different for all the plantar regions. These results were also different from previous research that used data from mechanical tests and experiments where the participant’s foot was static.

Conclusion: The viscoelastic ellipsoidal model was able to reproduce ground reaction force and determine the unique mechanical characteristics for each plantar region. Future uses of the model will be with clinical data collected from persons with plantar diseases, which could lead to predictions and preventions of plantar disease.

Keywords

Ground reaction force; Kinematics; Kinetics; Material model; Plantar contact area; Pressure-measuring insoles

Disciplines

Biomedical Engineering and Bioengineering | Engineering Science and Materials | Materials Science and Engineering | Mechanical Engineering

Language

English


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