Using new imaging technology, scientists have revealed how collagen fibres protect spinal discs from the stresses of everyday life, and why the same design could leave them vulnerable to damage.
An international team of scientists has discovered how some of the tiniest structures in the human spine help it cope with the strain of bending, lifting and everyday movement, potentially shedding new light on why spinal discs deteriorate.
The study, is published in Nature on November 4 and involves researchers at The University of Manchester, Queen Mary University and University College London, in collaboration with the ESRF -the European Synchrotron and Diamond Light Source.
They used powerful X-rays to examine what happens inside intervertebral discs at scales ranging from whole tissue down to individual collagen structures.
The imaging method, called TomoSAXS, combines different X-ray techniques to reveal in 3D how the collagen fibres that give discs strength respond when compressed.
They found collagen fibrils - tiny, strong strands made from many collagen molecules packed tightly together- are already under strain before additional pressure is applied, which may help discs withstand everyday loads but could also make some structures more vulnerable to damage.
Highly curved collagen fibres experienced particularly high strain, especially around the boundary between the disc's inner and outer regions, an area that may be more susceptible to damage and herniation.
Dr Alissa Parmenter, joint first author, from University College London said: "When we bend or lift, the forces within our spinal discs are shared between structures far smaller than we can see. With TomoSAXS, we can follow how the tissue deforms and connect that movement to changes within its nanoscale collagen building blocks. This helps us understand how the disc's intricate organisation allows it to carry load, and why some regions may be more vulnerable to damage."
The work also builds on imaging research developed at The University of Manchester by Dr Catherine Disney, whose earlier research pioneered ways of studying soft-tissue mechanics using X-ray tomography and later helped develop techniques for tracking collagen fibre movement in three dimensions.
Dr Disney said: "This study shows why long-term investment in synchrotron imaging and analysis methods matters.
"Seeing these approaches now integrated with TomoSAXS to connect the mechanics of the whole disc all the way down to nanoscale collagen is tremendously exciting."
Professor Himadri Gupta, joint senior author from Queen Mary University said: "The findings point to a potential trade-off in the way the disc is built. We found that substantial pre-stress within collagen fibrils may help the disc achieve the stiffness it needs to perform its role but could also leave some structures with less capacity to withstand additional damaging loads."
Dr Elis Newham from Queen Mary University, london, is joint first author. He said "Understanding how damage develops in the intervertebral disc requires us to look beyond the tissue as a whole. With this approach, we can start to connect what is happening to individual collagen structures with how the disc behaves as an organ. This could give us new ways to investigate the mechanical changes associated with ageing and disease."
The researchers stress the discovery is not a new treatment for back pain, but say the technology provides a powerful new way of investigating how damage begins and develops inside spinal discs.
The approach could eventually also help researchers study other collagen-rich tissues including tendons, cartilage and arteries.
- The paper, "Multimodal X-ray imaging reveals hierarchical fibre mechanics", is published in Nature. DOI https://doi.org/10.1038/s41586-026-11148-5
