An Analysis of Lumbar Muscle Load Distribution with and without the Presence of the Multifidus Muscle

Open Access
- Author:
- Esparragoza, Daniel
- Area of Honors:
- Mechanical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Daniel Humberto Cortes Correales, Thesis Supervisor
Daniel Humberto Cortes Correales, Thesis Honors Advisor
Anne Elizabeth Martin, Faculty Reader - Keywords:
- Lumbar Movement
Spinal Stability
Multifidus Muscle
Lumbar Muscles
OpenSim - Abstract:
- The goal of this research is to analyze spinal stability in relation to the multifidus muscle. Specifically, the study will evaluate if there is a significant effect on load distribution on the spine when the multifidus is deactivated. This is accomplished by analyzing the surrounding lumbar muscle tendon forces for different lumbar movements. Data was collected for three models and three distinct lumbar movements. The three models included the model developed Raabe and Chaudhari, a modified version of the Raabe and Chaudhari model where the multifidus entry level muscle isometric maximum force was reduced, and another modified model where the multifidus spinous process muscle isometric maximum force was reduced. The three distinct motions analyzed were flexion-extension, axial rotation, and lateral bending. Results show that the lumbar muscles on the modified models performed at higher tendon forces than the lumbar muscles from the original model. The results would indicate that the deactivation of the multifidus muscle would cause surrounding lumbar muscles to compensate by increasing their tendon force over a range of motion. These results were consistent for all the lumbar muscles and lumbar motions analyzed in this study. Furthermore, it was found that there is a difference to the extent in which the lumbar muscles change performance based on what part of the multifidus muscle was modified. The results show that the deactivation of the multifidus spinous process muscle has a greater impact on the performance of surrounding lumbar muscles than the deactivation of the multifidus entry level muscle.