Tendons and ligaments transfer forces from muscle to bone or between bones. They are made of collagen that is susceptible to both mechanical and chemical damage. Collagen damage can change the stiffness and strength of tendons or ligaments to cause pain and disability. It is difficult to study this type of tissue injury because we don't have good laboratory methods to see the damage as it occurs. This research will use a new imaging technique that can see tissue changes during mechanical loading. A novel video camera that sees properties of light that are invisible to the human eye will record how the linear structures of the tendons and ligaments are broken by loading that causes damage. Visually following the degradation of the collagen during the process of mechanical degeneration will make it possible to test new methods to prevent damage or to treat the injuries. The research will train graduate students in advanced biomechanics methods. The project includes writing a multimedia iBook on ligament and tendon function to improve interactive workshops for K-12 students and to make it easier to give biomechanics educational materials to the community.
The objective of this research is to use polarization imaging to advance the microstructural analysis of connective tissues and link the dynamic organization of soft tissues to altered mechanical function in damage and degeneration. This project will establish a novel reflected-light quantitative polarization light imaging (rQPLI) technique using a tissue analog experimental system and computational simulations. This technique will then be used to track local, mechanically-induced damage in fatigue-loaded ligament and to quantify time-dependent biologically-induced degeneration in tendon. rQPLI will overcome limitations of previous approaches and greatly advance polarization imaging for use in musculoskeletal mechanics. This study will examine intact, large-scale, full-thickness tissues that were impossible to evaluate previously, enabling detection and quantification of region-specific, microscopic, structural changes that occur during loading in real-time. This novel imaging technique will enhance optical measurement of tissue microstructure and advance polarization imaging techniques for applications in musculoskeletal biomechanics. Results will lay the foundation for future projects that further advance study of multiscale mechanics and microstructural evaluation, and enhance fundamental understanding of structure-function relationships in normal, damaged, degenerate, and healing connective tissues.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
