OpenSim Versus Human Body Model: A Comparison Study for the Lower Limbs During Gait.

Area of Science:

• Biomechanics
• Human Movement Analysis
• Computational Modeling

Background:

• Musculoskeletal modeling and simulations are widely used for analyzing human movement.
• End users often lack awareness of the underlying modeling and computational assumptions.
• These assumptions can influence the outcomes of biomechanical analyses.

Purpose of the Study:

• To investigate the impact of different musculoskeletal models on biomechanical gait analysis.
• To compare outcomes between the Human Body Model and the OpenSim gait2392 model.
• To identify how modeling assumptions affect joint kinematics, kinetics, and muscle forces.

Main Methods:

• Compared joint kinematics, kinetics, and muscle forces using two different musculoskeletal models (Human Body Model and OpenSim gait2392).
• Processed gait data from 7 healthy adults using both models.
• Analyzed differences in outcome variables, joint center locations, and pelvic reference frames.

Main Results:

• Statistically significant differences were observed in joint kinematics (e.g., hip rotation), kinetics (e.g., hip moment), and muscle forces (e.g., psoas).
• Differences in joint center locations and pelvic reference frames may explain these variations.
• Outcome variables showed similar patterns despite quantitative differences.

Conclusions:

• The choice of musculoskeletal model can influence the accuracy of kinematic and loading estimates in biomechanical analyses.
• In clinical settings focusing on deviations from reference data, model choice may have less impact.
• Careful consideration of model assumptions is necessary for reliable gait analysis outcomes.