Comparing Gait with Multiple Physical Asymmetries Using Consolidated Metrics.

Area of Science:

• Biomechanics
• Gait Analysis
• Human Movement Science

Background:

• Asymmetric gait arises from physical changes like leg length discrepancy, added mass, prosthetics, or stroke.
• Existing methods may not capture the overall impact of multiple asymmetries on gait.
• A unified metric is needed to benchmark and differentiate various asymmetric bipedal gaits.

Purpose of the Study:

• To introduce and validate the combined gait asymmetry metric (CGAM) as a benchmark for categorizing and differentiating asymmetric bipedal gaits.
• To assess the metric's ability to reflect overall gait symmetry changes and distinguish between different gait conditions.

Main Methods:

• Developed the CGAM based on modified Mahalanobis distances.
• Utilized spatio-temporal, kinematic, and kinetic gait parameters from motion capture and force data.
• Applied the metric to analyze gaits with leg length discrepancy, distal mass, prosthetic use, and stroke.

Main Results:

• The CGAM successfully measured overall gait symmetry across eleven parameters.
• The metric differentiated between gaits with multiple physical asymmetries.
• Distal mass had a greater impact on asymmetry than leg length discrepancy; combined effects showed parameter cancellation.
• Prosthetic gait differed from able-bodied gait across walking velocities.

Conclusions:

• The CGAM provides a consolidated measure for overall gait asymmetry.
• It aids in identifying improvements in gait symmetry and understanding complex interactions between different asymmetries.
• The metric is effective in distinguishing between various asymmetric gaits, including those involving prosthetics.