Measuring three-dimensional strain distribution in tendon

Area of Science:

• Biomechanics
• Biomedical Engineering
• Orthopedics

Background:

• Tendons transfer muscle force to bone, enabling skeletal movement.
• Mechanical stress significantly impacts tendon healing and injury risk.
• Understanding local strain and displacement is vital for tendon research.

Purpose of the Study:

• To introduce a novel 3D image processing technique for analyzing tendon strain and displacement.
• To investigate the mechanisms of load transfer within tendons under mechanical stress.
• To identify different modes of tendon deformation during loading.

Main Methods:

• Utilized a novel three-dimensional (3D) image processing technique.
• Employed the Sheffield Image Registration Toolkit for data analysis.
• Analyzed local strain and displacement distribution in tendon samples.

Main Results:

• Local normal strain in the loading axis was lower than the global applied load.
• Fiber sliding was identified as a primary load-transfer mechanism.
• Observed three distinct deformation modes: parallel sliding, twisting, and transverse deflection.

Conclusions:

• The novel 3D image registration method effectively analyzes out-of-plane movements in tendons.
• Tendon deformation involves complex fiber sliding and varied modes, not detectable by 2D methods.
• This technique enhances the understanding of tendon mechanics, injury, and healing processes.