Biomechanical Risk Factors of Lower Extremity Overuse Injury Related to Fatigue

Abstract

The primary interest of the presented dissertation was to evaluate fatigued running gait biomechanics for the identification of prospectively collected risk factors for the development of lower extremity overuse injuries. Four manuscripts were completed in order to gain a more complete understanding of biomechanical risk factors of lower extremity overuse injury related to fatigue. A methodological analysis of the calculation models of leg stiffness, and the effect of body mass on leg stiffness, was performed to evaluate the most appropriate calculation and reporting methods for leg stiffness, a biomechanical variable potentially useful in the identification of overuse injury development. An evaluation of limb asymmetry, at both rested and fatigued states, was performed to gain insight into normal levels of asymmetry between limbs, as the development of lower extremity overuse injuries is often unilateral. The preliminary investigation on the effects of an aerobic fatigue protocol on countermovement jump kinetics provides a potential measure of the presence and level of fatigue that is more objective in nature than self-reported ratings of perceived exertion or fatigue. Finally, a prospective analysis of biomechanical risk factors for the development of knee overuse injury was completed, including investigations into risk factors present at rested and fatigued state, and changes in gait due to fatigue that differ between injured participants and controls. These manuscripts represent the progression of a research agenda investigating biomechanical risk factors for the development of lower extremity overuse injury related to fatigue and the foundation for future research in this chosen field.