Date of Award
Master of Science (MS)
The purpose of this study was to validate a 3D musculoskeletal model in OpenSim and assess OpenSim’s ability to determine muscle-length variation during ambulation. An 18 camera motion capture system was used to analyze 20 healthy individuals between the ages of 18 and 35. Following data collection, the data was processed through OpenSim and Visual3D. The kinematic output processed through the OpenSim model was then compared to the kinematic output of the validated Visual3D model to validate the OpenSim model. Muscle fiber length data obtained from the same experimental data was compared to control data to assess OpenSim’s muscle analysis functions. Spatiotemporal parameters including walking speed, left and right cadence, and stride length were also compared between the processed output from OpenSim and Visual3D. The mean maximum, minimum, and range of kinematics and muscle length data were calculated from the experimental and control data for comparison. Paired t test statistical analysis was performed in comparing the right and left limb kinematics between OpenSim and Visual3D. One sample t test statistical analysis was performed in comparing the muscle-length output from the experimental and control data. Both statistical tests were conducted at a 95% confidence interval. The paired t test statistical analysis concluded varying results of significant similarities and differences at each joint during stance and swing phase between both sets of data. The one sample t test also resulted in varying results of significant similarities and differences for muscles in stance and swing phase between both sets of data. OpenSim has variability in calculating inverse kinematics. Differences in the software compared to Visual3D support this claim. OpenSim’s ability to calculate muscle-length changes sets it apart from Visual3D. The difference in anatomical modeling in OpenSim and Visual3D attributes to their difference in kinematic output. OpenSim’s multitude of functions allows it to analyze different biomechanical aspects of human motion analysis. OpenSim’s ability to determine inverse kinematics and muscle-length variation during gait can ultimately help physicians, biomedical engineers and clinicians to further assess motion analysis and properly prescribe restorative surgeries and therapies.