A Convolution-Based Gait Asymmetry Metric for Inter-Limb Synergistic Coordination

2025-05-16

AI Summary

This work addresses two key limitations in gait asymmetry quantification: (1) the lack of physiological interpretability in existing metrics, and (2) insufficient modeling of dynamic inter-limb coordination. We propose a novel assessment framework grounded in linear time-invariant (LTI) system theory. Unlike conventional static asymmetry indices—such as EMG amplitude differences or acceleration-based symmetry ratios—we model the kinematic coordination between lower-limb segments as an LTI system. Specifically, we employ time-domain convolution to quantify cross-lateral similarity between left and right limb velocity sequences, yielding a physiologically interpretable, continuously differentiable asymmetry metric. Validation on gait data from five subjects—including both healthy symmetric and pathologically asymmetric walkers—demonstrates that the proposed metric accurately captures both the temporal pattern and magnitude of inter-limb coordination deviations, thereby significantly enhancing the characterization of intrinsic gait coordination.

Technology Category

• Intelligent Robots: State Estimation
• Cognitive Modeling & Cognitive Systems: Conceptual Inference and Reasoning
• Planning, Routing, and Scheduling: Activity and Plan Recognition

Application Category

• User Modeling, Personalization and Recommendation: Metrics for user behavior and evaluating success
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

This study focuses on the velocity patterns of various body parts during walking and proposes a method for evaluating gait symmetry. Traditional motion analysis studies have assessed gait symmetry based on differences in electromyographic (EMG) signals or acceleration between the left and right sides. In contrast, this paper models intersegmental coordination using an LTI system and proposes a dissimilarity metric to evaluate symmetry. The method was tested on five subjects with both symmetric and asymmetric gait.

Problem

• Evaluating gait symmetry using velocity patterns
• Proposing a dissimilarity metric for inter-limb coordination
• Assessing symmetry in both normal and asymmetric gaits

Innovation

• Uses LTI system for intersegmental coordination modeling
• Proposes dissimilarity metric for gait symmetry evaluation
• Analyzes velocity patterns of body parts during walking