Dissertation Defense: Differences in Lower Extremity Muscle Function and Coordination during Gait between Older and Young Adults
- Dr. Robert Siston, Chair
- Dr. Ajit Chaudhari
- Dr. Laura Schmitt
This dissertation proposes to determine differences in muscle function and motor control during gait between young and older adults. Given the need for musculoskeletal modeling and simulation techniques to estimate muscle contributions to COM acceleration, we first determined how the use of four different musculoskeletal models affected simulated joint mechanics, muscle activation, and muscle forces. We then chose one model to develop muscle-driven simulations of walking in both older and young adults to investigate differences in individual muscle contributions to COM accelerations between age groups. In an effort to explicitly investigate how differences in joint kinematics affect the ability of muscles to facilitate movement, we developed a 4-link 2D sagittal plane model with four revolute joints that was used to calculate the potential of individual muscles to contribute to support and progression in a wide range of kinematic states that could be observed during walking and rising from a chair. To evaluate the role of motor control in differences between older and young adult gait, we identified muscle synergies in each age group. The research presented in this dissertation integrates computational methods, gait analysis techniques, and dynamic computer simulations.