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Validation of smoothness evaluation during standing and sitting motions using an accelerometer
Takeshi Shimamura1, Hiroshi Katoh2
1Department of Rehabilitation, Kumamoto Kenhoku Hospital: 550 Tamana, Tamana-shi, Kumamoto 865-0005, Japan.
Journal of Physical Therapy Science
|April 5, 2021
Summary
This study quantitatively evaluates motion smoothness using accelerometer data during standing and sitting. Unstable conditions showed higher motion indices, with root mean square negatively correlating with entropy under normal conditions.
Area of Science:
- Biomechanics
- Motion Analysis
- Wearable Sensors
Background:
- Assessing motion smoothness is crucial for understanding human movement.
- Accelerometers offer a portable method for quantitative motion analysis.
Purpose of the Study:
- To quantitatively evaluate motion smoothness during standing and sitting using accelerometer data.
- To investigate the relationship between different motion analysis indices.
Main Methods:
- Seventeen healthy males performed standing and sitting motions under normal and unstable conditions.
- A 9-axis motion sensor was attached to the third lumbar spine to measure acceleration.
- Root mean square and entropy were calculated in lateral, vertical, longitudinal, and triaxial directions.
Main Results:
- Unstable conditions yielded significantly higher motion indices compared to normal conditions, except for lateral entropy.
- A significant negative correlation was found between root mean square and entropy under normal conditions.
Conclusions:
- Accelerometer-based indices effectively quantify motion smoothness.
- Different indices possess unique characteristics, highlighting the significance of motion-specific measures.
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