Modeling thoracolumbar fascia mechanical tensile behavior with microstructure-level descriptors

Area of Science:

• Biomechanics
• Computational modeling
• Tissue engineering

Background:

• Fasciae play a role in chronic pain, but their mechanical modeling is limited.
• Understanding fascia mechanics is crucial for pain prevention and treatment.
• Existing models do not directly link macroscopic behavior to mesoscale structure.

Purpose of the Study:

• To develop a computational model simulating fibrous tissue mechanical behavior from its mesostructure.
• To investigate the mechanical properties of the thoracolumbar fascia as a case study.
• To provide a numerical framework for exploring how fascial architecture influences mechanical properties relevant to pain.

Main Methods:

• Developed a discrete element model representing collagen fibers as springs and the matrix as beams.
• Simulated uniaxial tensile tests on the thoracolumbar fascia with varying fiber properties.
• Evaluated model performance through fiber property influence, experimental validation, anisotropy assessment, and inter-fiber contact analysis.

Main Results:

• The model demonstrated a range of hyperelastic behaviors adaptable to different fascia types.
• Numerical simulations closely matched experimental tensile data, validating the model's accuracy.
• The model revealed anisotropic behavior consistent with preferential fiber orientation and the impact of inter-fiber contact on stress distribution.

Conclusions:

• The discrete element model successfully reproduces experimental fascia tensile behavior.
• The model provides insights into local mechanical responses and anisotropy in fibrous tissues.
• This work offers a framework for understanding fascia mechanics and its contribution to chronic pain.