A gait abnormality measure based on root mean square of trunk acceleration

Area of Science:

• Biomechanics
• Gait Analysis
• Medical Engineering

Background:

• Trunk acceleration's root mean square (RMS) is common in gait analysis but influenced by walking speed.
• This speed dependency complicates using RMS to assess gait abnormality.
• A novel metric, the RMS ratio (RMSR), was proposed to account for this.

Purpose of the Study:

• To investigate the relationship between walking speed and RMSR in healthy individuals.
• To determine if RMSR can effectively discriminate between healthy and abnormal gaits.
• To propose RMSR as a potential quantitative measure for gait abnormality.

Main Methods:

• Recruited 47 healthy males and 20 hemiplegic males for gait analysis.
• Attached a tri-axial accelerometer to the lower back of participants.
• Measured RMSR, defined as RMS ratio to RMS vector magnitude, during preferred speed walking.

Main Results:

• In healthy subjects, RMS in all directions correlated with walking speed.
• RMSR in the mediolateral (ML) direction showed no correlation with walking speed in healthy individuals.
• Hemiplegic patients exhibited significantly higher ML RMSR compared to healthy subjects.

Conclusions:

• ML RMSR remains consistent in healthy individuals across different preferred walking speeds.
• Abnormal gaits, such as hemiplegia, show deviations in ML RMSR from healthy norms.
• ML RMSR shows potential as a quantitative biomarker for gait abnormality.