Method for measuring tri-axial lumbar motion angles using wearable sheet stretch sensors.

Area of Science:

• Biomechanics
• Wearable Technology
• Occupational Health

Background:

• Occupational low back pain is a significant concern, particularly for healthcare workers, with trunk movements being identified as key risk factors.
• Wearable motion capture systems offer a promising solution for monitoring these movements and mitigating risks.
• This research introduces a novel system utilizing sheet stretch sensors for lower back movement estimation.

Purpose of the Study:

• To develop and validate a novel wearable motion capture system using sheet stretch sensors.
• To assess the system's accuracy in estimating lumbar motion angles during various trunk movements.
• To explore the potential of this system for monitoring healthcare workers and preventing low back pain.

Main Methods:

• Six volunteers performed seven types of uniaxial and multiaxial trunk movements.
• Four stretch sensors were attached to each participant's lower back.
• Lumbar motion angles were estimated using linear regression and compared to an optical motion capture system.

Main Results:

• The stretch sensor system demonstrated good correlation with actual lumbar motion angles (r = 0.60-0.72, P < 0.05).
• Estimation errors for flexion-extension, side-bending, and rotation were consistently below 3°.
• The system provided accurate three-directional angle estimations.

Conclusions:

• The developed stretch sensor system provides reasonable estimates of lumbar motion angles.
• This novel, wearable motion capture system offers freedom from capture space limitations.
• The system shows significant potential for monitoring lower back movement in healthcare workers to prevent injuries.