Muscle force estimation in clinical gait analysis using AnyBody and OpenSim

Area of Science:

• Biomechanics
• Musculoskeletal modeling
• Gait analysis

Background:

• Musculoskeletal models are crucial for estimating muscle forces during gait.
• Variations in modeling assumptions and approaches can impact results.
• Direct comparisons of standard modeling environments are infrequent.

Purpose of the Study:

• To compare joint kinematics, kinetics, and muscle forces between AnyBody and OpenSim.
• To investigate the influence of different modeling environments on gait analysis outputs.
• To identify specific differences in muscle force estimations between the two platforms.

Main Methods:

• Utilized experimental gait data from 10 healthy participants.
• Applied standard static optimization routines in AnyBody and OpenSim.
• Employed two gait-specific musculoskeletal models for analysis.
• Used statistical parameter mapping and paired t-tests for waveform comparison.

Main Results:

• Observed significant differences in sagittal ankle and hip angles, and sagittal knee moments.
• Identified discrepancies in estimated forces for specific muscles, notably the triceps surae group and biceps femoris short head.
• Attributed differences to variations in anthropometric/anatomical definitions and scaling procedures.

Conclusions:

• Distinct differences exist in individual muscle force estimations between AnyBody and OpenSim.
• These discrepancies stem from differing model parameters and scaling methods.
• Understanding these variations is vital for effective clinical implementation of musculoskeletal modeling.