Date on Master's Thesis/Doctoral Dissertation

8-2017

Document Type

Master's Thesis

Degree Name

M. Eng.

Department

Bioengineering

Degree Program

JB Speed School of Engineering

Committee Chair

Voor, Michael

Committee Member

Magnuson, David

Committee Member

Roussel, Thomas

Author's Keywords

hip fracture; exercise; biomechanics; bone remodeling; proximal femur; finite element anaylsis

Abstract

Based on the principles of cutting edge bone remodeling research, a unique therapeutic exercise device was designed specifically to improve bone quality at the most critical location of the proximal femur prone to fracture: the superior-lateral femoral neck where the fracture first initiates during a fall. The exercise/device is intended to work by inducing enough strain in the bone to stimulate the body’s natural bone remodeling mechanisms to increase bone density in the proximal femur and consequently prevent a fracture from arising if a fall to the side does occur.

In order to test the proposed exercise, experiments simulating the exercise were completed using a prototype device and (1) an artificial composite femur, (2) an ex-vivo cadaveric femur and (3) in-situ in a cadaver. Strains were measured at three locations on the femurs, including the lateral neck, medial neck and medial shaft. Additionally, in order to optimize the exercise and test its safety and effectiveness, a computer model representing a femur and the applied loading conditions of the exercise was developed and a finite element analysis (FEA) was performed.

Results show that the proposed exercise has the potential to produce high enough strain magnitudes (>1,000µε) and strain rates (>10,000µε/s) in the superior-lateral femoral neck in order to induce anabolic bone remodeling, while being well below the fracture limit in any area of the femur. This suggests that the proposed exercise could be a beneficial therapy for strengthening the proximal femur and may aid in the prevention of hip fractures.