Fatigue Detection during Sit-To-Stand Test Based on Surface Electromyography and Acceleration: A Case Study.

Area of Science:

• Biomedical Engineering
• Rehabilitation Science
• Wearable Technology

Background:

• The 30-second sit-to-stand (30-STS) test traditionally measures repetitions.
• Emerging research explores kinematic and muscular activity for fatigue assessment.
• Electromyography (EMG) is a criterion standard for muscle fatigue analysis.

Purpose of the Study:

• To develop a smartphone-based system for analyzing fatigue during the 30-STS test.
• To utilize trunk acceleration as a novel indicator of fatigue.
• To compare smartphone acceleration data with surface electromyography (EMG) as the criterion.

Main Methods:

• A case study involving one participant performing eight 30-STS trials.
• Recording of lower limb and trunk muscle EMG signals and trunk acceleration.
• Signal processing included Discrete Fourier Transform for EMG's spectral centroid and Discrete Wavelet Transform for acceleration's energy percentage.

Main Results:

• EMG analysis indicated vastus medialis fatigue via a decrease in spectral centroid starting at second 12.
• Acceleration analysis revealed fatigue-like patterns with increased relative energy percentage starting at second 19.
• The study assessed fatigue using two distinct signal types.

Conclusions:

• Smartphone-based acceleration analysis can detect fatigue during the 30-STS test.
• This approach offers an accessible and cost-effective method for clinicians.
• Future applications may involve remote and widespread fatigue monitoring.