Determination of gait events using an externally mounted shank accelerometer

Area of Science:

• Biomechanics
• Gait Analysis
• Wearable Sensors

Background:

• Accurate determination of foot contact events is crucial for biomechanical analysis.
• Force platforms are the standard for measuring these events, but their use is limited by availability and cost.
• Alternative methods are needed for accessible gait event detection.

Purpose of the Study:

• To evaluate the efficacy of using accelerometers mounted on the distal tibia to determine gait events.
• To compare the accuracy of accelerometer-based gait event detection with traditional force platform measurements.

Main Methods:

• Sixteen participants ran at a controlled speed (4.0 m/s ± 5%).
• Axial accelerations from tibial-mounted accelerometers and vertical ground reaction forces from force platforms were simultaneously recorded at 1000 Hz.
• Gait events (heel strike, toe-off) and stance phase duration were determined using both methods and compared.

Main Results:

• The accelerometer method showed mean errors of 1.68 ms (average) and 5.46 ms (absolute) for heel strike detection.
• Mean errors for toe-off detection were -3.59 ms (average) and 5.00 ms (absolute).
• Stance phase duration errors were 5.18 ms (mean) and 11.47 ms (absolute), with a strong correlation (r = .96) to force platform data.

Conclusions:

• Shank-mounted accelerometers provide accurate and reliable detection of gait events.
• This method offers a viable and accessible alternative to force platforms for biomechanical analysis.
• The findings support the use of wearable sensors for objective gait assessment.