The development and concurrent validity of a real-time algorithm for temporal gait analysis using inertial...

Area of Science:

• Biomechanics
• Wearable Technology
• Clinical Gait Analysis

Background:

• Inertial measurement units (IMUs) are increasingly used for gait analysis in clinical settings.
• Shank gyroscope signals are key for detecting gait events like heel-strike and toe-off.
• Existing algorithms like the dual minima method (DMM) may miscalculate gait parameters, particularly toe-off timing.

Purpose of the Study:

• To introduce and validate a real-time algorithm, Noise-Zero Crossing (NZC), for accurate temporal gait parameter calculation.
• To compare the concurrent validity of NZC-derived gait parameters against an instrumented walkway.
• To assess the accuracy and precision of NZC compared to the DMM algorithm.

Main Methods:

• Development of a real-time Noise-Zero Crossing (NZC) algorithm utilizing shank gyroscope data.
• Concurrent validation of NZC against an instrumented walkway for gait event detection.
• Comparative analysis of NZC and DMM algorithms using Bland-Altman analysis.

Main Results:

• The NZC algorithm demonstrated excellent agreement with the instrumented walkway for Gait Cycle Time (GCT), Single Limb Support (SLS), and Double Limb Support (DLS) time.
• NZC showed superior performance over DMM in measuring SLS and DLS times by accurately identifying toe-off.
• The NZC algorithm's precise detection of toe-off preserves critical DLS time measurements.

Conclusions:

• The NZC algorithm provides accurate and precise temporal gait parameters, outperforming the DMM.
• Accurate measurement of DLS time using NZC has significant implications for assessing pathological gaits.
• NZC represents a valuable advancement for IMU-based clinical gait analysis.