Physiologically corrected coupled motion during gait analysis using a model-based approach.

Area of Science:

• Biomechanics
• Motion Analysis
• Clinical Gait Assessment

Background:

• Gait analysis is crucial for patient evaluation, often using stereophotogrammetric systems.
• Reproducibility issues in gait analysis stem from skin displacement artifacts, affecting secondary motion accuracy.
• A model-based approach (MBA) was developed to integrate joint kinematics and motion data, addressing these limitations.

Purpose of the Study:

• To extensively validate the model-based approach (MBA) for gait analysis.
• To compare MBA results against a conventional motion representation model, the Plug-in Gait model (PiG).
• To assess the accuracy of joint range-of-motion calculations for pelvis, hip, knee, and ankle.

Main Methods:

• Thirty-five healthy subjects underwent gait analysis using a stereophotogrammetric system.
• Gait data were processed using both the Plug-in Gait model (PiG) and the model-based approach (MBA).
• Statistical comparisons included paired-sample t-tests, normalized root-mean-square errors, and coefficient of multiple correlations for curve shape analysis.

Main Results:

• Both MBA and PiG showed similar results for primary plane of motion displacement.
• Statistically significant discrepancies were observed between MBA and PiG for combined motion analysis.
• MBA demonstrated improved accuracy in approximating joint kinematics, particularly for complex movements.

Conclusions:

• The model-based approach (MBA) provides more accurate gait analysis, especially for combined joint motions, compared to conventional methods.
• MBA's integration of validated joint mechanisms makes it suitable for advanced applications like musculoskeletal modeling.
• This validated MBA enhances the reliability of clinical gait evaluations and follow-ups.