A Novel Approach for Improving Gait Speed Estimation Using a Single Inertial Measurement Unit Embedded in a...

Area of Science:

• Biomedical Engineering
• Gait Analysis
• Wearable Technology

Background:

• Gait speed is a key health biomarker, but current measurement methods are costly and require supervision.
• Smartphones with inertial measurement units (IMUs) offer a convenient, accessible alternative for gait speed assessment.
• Previous research utilized trunk-mounted IMUs; effectiveness with smartphone IMUs in pockets remains unclear.

Purpose of the Study:

• To validate and assess the reliability of smartphone IMU-based gait speed measurement.
• To evaluate performance in healthy young and older adults during normal and dual-task walking.
• To determine feasibility when the smartphone is placed in a front pants pocket.

Main Methods:

• A custom smartphone application recorded gait data from 24 participants (12 young, 12 older adults).
• Gait speed and step length were compared against the GAITRite mat (gold standard).
• A coefficient-based adjustment was applied to step length to enhance gait speed accuracy.

Main Results:

• Smartphone gait speed measurement showed validity against the GAITRite mat.
• Initial limits of agreement (0.50 m/s) and regression slope (1.68) improved post-adjustment to 0.34 m/s and 1.00, respectively.
• Excellent test-retest reliability was observed in both lab and home settings.

Conclusions:

• The inverted pendulum approach with smartphone IMUs is valid and reliable for gait speed estimation.
• Step length adjustment effectively removed bias and improved gait speed accuracy.
• This method holds promise for diverse populations and settings, with potential for fine-tuning.