Date of Completion


Embargo Period



Lagrange, Modeling, Biodynamics, Pitching

Major Advisor

Donald R. Peterson

Associate Advisor

Carl W. Nissen

Associate Advisor

Kevin S. Brown

Associate Advisor

David M. Pierce

Associate Advisor

Pouran D. Faghri

Field of Study

Biomedical Engineering


Doctor of Philosophy

Open Access

Open Access


Biomechanical modeling can provide information regarding movement patterns and allow for an improved understanding of injury mechanisms. Biomechanical models typically rely on Newtonian mechanics leading to computationally intensive models; however, an often overlooked means of solving these same modeling needs is to apply the Lagrangian approach. This approach allows for a more direct means of solving the equations of motion; leading to more accurate models of human motion. The purpose of this project was to create a Lagrangian based model of the upper extremity to describe joint kinematics and kinetics as well as muscle kinetics during complex motion tasks.

The model developed in this work was a four segment, 18 degree of freedom model capable of providing joint moments as well as muscle force estimates. The model was then applied to data collected from 33 collegiate level baseball pitchers. The results of this project indicated that the model was capable of accurately predicting the motion profiles of the upper extremity joints. The results also indicated that the model was able to accurately estimate muscle forces leading to a greater understanding of pitching related injuries. The adaptability of the model offers the ability to create patient specific treatment plans or modify a pitcher’s mechanics to decreased joint moments. Finally, the results of this work illustrate the utility of using Lagrangian based biomechanics models to create accurate and adaptable models to describe complex human movement.