William Ledoux, Ph.D.
VA Center of Excellence for Limb Loss Prevention and Prosthetic Engineering
E-mail: wrledoux@u.wa...


TITLE:

"Foot Biomechanics: Robotic Gait Simulation, Finite Element Modeling and Mechanical Testing"


ABSTRACT:

For the last decade or so, the VA RR&D Center of Excellence for Limb Loss Prevention and
Prosthetic Engineering has been striving for a more comprehensive approach to quantifying foot
biomechanics.  As such, we have developed a multi-faceted research program that merges studies
on living subjects with both cadaveric and computational models.  Data from the VA Motion
Analysis Laboratory (e.g., normal tibial to ground motion) are used to guide our Robotic Gait
Simulator, while data from the Robotic Gait Simulator are employed to guide clinical decision
making (e.g., optimal fusion angle of the great toe joint).  Mechanical testing of cadaveric
tissues (foot ligaments or plantar soft tissue) generates parameters that are used in our
computational modeling efforts, while our finite element foot models are used to study internal
tissue stresses.

This seminar will briefly address three specific studies that we are recruiting students for.
The first study involves the dynamic simulation of gait using cadaveric feet and the Robotic
Gait Simulator.  The project will include the simulation and comparison of two flat foot
reconstructive procedures.  The second study involves further development of the finite element
foot model.  We will generate patient specific computational models using CT and MRI scans, as
well as specialized MRI loading devices.   The third study involves the mechanical testing of
foot ligaments.  We are interested in determining how diabetes effects the mechanical
properties of foot tissues, specifically ligaments.  Finally, I will also very briefly describe
our biplane fluoroscope, a device used to track the motion of individual bones of the foot
during walking.