3D Musculoskeletal Modelling of the Human Lower Extremity

• Author / Creator

  Feddema, Jasmine

• Modeling of human musculature is of interest to anatomists and biomechanists for its ability to predict human motion. In current models, muscles are portrayed as connecting lines starting at the origin and ending at the insertion, however this modeling often does not account for the wrapping that occurs at muscles like the vasti. In particular, the vastus medialis oblique, has a unique oblique orientation, which may indicate a specialized action on the femur. Additionally, the specific geometry of the bones is not typically incorporated in current models. The omission of proper musculoskeletal geometry from models limits their ability to accurately predict muscular action and human motion. The purpose of this study was to develop a comprehensive three-dimensional model that included specific bone geometry and proper muscle paths, that could determine the contribution of the vasti muscles to a moment about the longitudinal axis of the femur.
  It was hypothesized that the vastus medialis oblique would exert the highest moment about the longitudinal axis of the femur because of its oblique fiber orientation. Specific bone geometry was collected using three sets of lower extremity cadaver bones with surface geometry captured using three-dimensional photogrammetry. Ten participants were recruited to perform maxima vertical jumps to obtain knee joint kinematics and kinetics. They also performed maximal isometric knee extension tests to determine the upper boundary for the knee extensor moment. The digitized bony landmarks of each cadaver model were transformed to follow the limb kinematics of each participant’s vertical jumps, and forces and moments experienced at the patella and femur were calculated. It was found that most of the moments exerted by the vasti muscles about the longitudinal axis of the femur were meaningful (>0.12 Nm/Kg), although the vastus medialis oblique alone did not exert a meaningful moment (<0.06 Nm/Kg). A net internal rotation moment was found, driven by the vastus intermedius and the vastus lateralis (≥0.10 Nm/Kg). When comparing bone models, it was found that there were meaningful differences between models that highlighted the importance of bone geometry on the force and moment production. The most unexpected finding was that the muscles attached to the patella were all pulling medially at the highest incidence of knee extensor moment, alluding to another counter force other than the patellar ligament, quadriceps tendon, and vastus medialis oblique tendon that is active within the knee joint and requiring further investigation. The findings in this study are beneficial for progression of musculoskeletal modeling techniques and uncover further insight about the functionality of the knee extensor mechanism.

• Subjects / Keywords

  • Modelling
  • Musculoskeletal system
  • Muscles
  • Bones
  • Musculoskeletal system, examination

• Graduation date

  Fall 2024

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-bcfj-tt21

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.