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Harmonic ratios: a quantification of step to step symmetry
J L Bellanca1, K A Lowry, J M Vanswearingen
1Department of Bioengineering, University of Pittsburgh, USA.
Journal of Biomechanics
|January 16, 2013
Summary
The harmonic ratio (HR) measures walking by analyzing trunk accelerations. This study clarifies HRs, suggesting they better represent step-to-step symmetry than walking smoothness or stability.
Area of Science:
- Biomechanics
- Gait Analysis
- Signal Processing
Background:
- The harmonic ratio (HR) is increasingly used to assess locomotion.
- Existing explanations of HR methodology are limited, hindering its application.
- Understanding HRs is crucial for investigating pathologies affecting gait.
Purpose of the Study:
- To provide a clear mathematical description of the harmonic ratio (HR).
- To enhance the interpretation of HRs in gait analysis.
- To redefine HRs as a measure of step-to-step symmetry.
Main Methods:
- Fourier analysis of trunk accelerations.
- Explanation of harmonic theory and HR interpretation.
- Application of HR analysis to sinusoidal and real gait data.
Main Results:
- Demonstration of HR calculation using sinusoidal signals.
- Illustration of HR analysis with trunk acceleration data during limb-loading.
- Proposed redefinition of HR as a measure of step-to-step symmetry.
Conclusions:
- The harmonic ratio (HR) method requires clearer definition and interpretation.
- HRs may be more accurately described as a measure of step-to-step symmetry.
- This work provides a foundation for applying HRs in clinical and research settings.
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