The dynamic disk plays a significant role in the resistance to compression. It is known to physically compress over the course of the day by as much as 20 percent with recovery achieved during sleep or recumbency. Its implications intertwined with back pain. 1 One of the focused investigations into its essential function has been its intrinsic ability to maintain and absorb water. Negatively charged proteoglycans contain properties that attract water, and it is this hydraulic characteristic believed to be at the core.
However much still is to be discovered; especially in the higher understanding how best to draw in fluid and recover the expulsion of this water under axial compression. In a manuscript published in the Journal of Biomechanics 2, researchers worked to answer the questions regarding loading and unloading of the dynamic disk.
The researchers revealed a new personality of the annulus fibrosis as playing a significant in the ability to absorb water. The annulus demonstrated both properties of viscoelasticity as well as the binding capacity to retain water. This information is new in the better understanding of how disks maintain vertebral spacing with regards to recovery. Load and unloading cycles are natural, but it is the intrinsic ability of the dynamic disk to maintain spacing over time that is important to continue to study. Congratulations to the authors for choosing a worthy investigation.
At Dynamic Disk Designs, we work to model the dynamic nature of the spinal structures to improve communication of spine science. Our work facilitates patient education and student teaching of spine. Having a model dynamic disk allows the better understanding of disk height loss over time to explain back pain mechanics and the respective hydraulic solutions.
- Livshits, G., Popham, M., Malkin, I., Sambrook, P.N., Macgregor, A.J., Spector, T., Williams, F.M., 2011. Lumbar disc degeneration and genetic factors are the main risk factors for low back pain in women: the UK Twin Spine Study. Ann. Rheum. Dis. 70, 1740–1745. ↩
- Emanuel KS1, van der Veen AJ2, Rustenburg CME1, Smit TH3, Kingma I4.Osmosis and viscoelasticity both contribute to time-dependent behaviour of the intervertebral disc under compressive load: A caprine in vitro study. J Biomech. 2017 Oct 25. pii: S0021-9290(17)30542-0. doi:10.1016/j.jbiomech.2017.10.010. ↩