A new approach to quantify asymmetry in human movement

Area of Science:

• Biomechanics
• Human Movement Analysis
• Sports Science

Background:

• Human movement asymmetry, the deviation from symmetry, is crucial in understanding performance and injury risk.
• Existing methods for quantifying asymmetry, like arbitrary thresholds, often overlook interindividual variability and clinical relevance.
• A need exists for robust methods to assess bilateral differences in human movement.

Purpose of the Study:

• To propose a novel approach for quantifying human movement asymmetry.
• To critically evaluate existing methods for assessing bilateral differences.
• To provide a more rational framework for understanding asymmetry in human movement, integrating statistical and clinical significance.

Main Methods:

• Introduction of the probability of agreement as a metric for quantifying limb symmetry.
• Development of a plot to visually summarize the agreement between measures from two limbs.
• Illustration of the approach using data from athletes' sports training and rehabilitation.

Main Results:

• The probability of agreement metric demonstrates how limb agreement is influenced by the clinically acceptable difference.
• Larger clinically acceptable differences result in increased agreement, while smaller differences decrease it.
• The proposed method accounts for interindividual variability in movement analysis.

Conclusions:

• The probability of agreement offers a statistically sound and clinically relevant method for quantifying human movement asymmetry.
• This approach enhances the understanding of bilateral differences in contexts like sports training and rehabilitation.
• Openly accessible data and codes facilitate replication and further research in human movement asymmetry.