Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair/Advisor

John DesJardins

Committee Member

Ge Lv

Committee Member

Tyler Harvey

Committee Member

William Richardson


Individuals with transfemoral amputation often rely on a prosthesis as a replacement for their missing extremity’s structure and function. Lower-limb prosthetic devices are developed with the goal of restoring biomechanical abilities and mitigating secondary health risks for users. However, biomechanical deficits for unilateral transfemoral prosthesis users are very common and are induced by both leg length discrepancy (LLD) and current prosthetic design shortcomings. Lack of push off power as well as difficulty shortening the leg for toe clearance can result in gait compensations that lead to asymmetric limb loading, increased muscle activity, and an increased incidence of falling due to poor balance, tripping and knee buckling. The overarching goal of this research was to develop novel technologies for use in optimizing gait biomechanics of unilateral transfemoral prosthesis users based on the principle of dynamic leg length (DLL).

First, a predictive, trigonometric model was developed and validated for DLL against experimental motion capture data. Following this, a more compact electromechanical prosthesis was developed based on the predictive model. This prosthesis can accurately adjust actuation speed to user’s walking cadence and has optimized timing for leg length changes based on push-off and toe clearance. Finally, the tuned length-actuated prosthesis was tested with prosthesis users to evaluate gait biomechanics. Results of this testing showed that the device was able to provide proper stability and propulsion during stance, but participants still exhibited several compensatory mechanisms for toe clearance.

Overall, both the DLL model for prosthesis prescription and the length-actuated prosthesis provide accurate and novel tools for encouraging functional symmetry for individuals with transfemoral amputation. The clinical impact of our research has been in mitigating safety risks and secondary conditions for unilateral transfemoral prosthesis users.

Author ORCID Identifier


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