Treatment strategies related to intervertebral disc displacement often involves extension. Robin McKenzie’s work on centralization of symptoms in the case of disc herniation has been used by many. Most of the research on migration nucleus pulposus has been previously investigated in the lumbar spine. In a recent study published in PM&R 1 , researchers looked at the cervical spine and wondered if this was a similar case. They hypothesized that cervical extension would centralize and shift the nucleus anterior–away from the associated disc herniation.
They looked at 10 healthy young males with mean age of 22 yrs old and compared neutral to extension position of the cervical discs using MRI. They carefully mapped out the nucleus pulposus and found that in extension the migration nucleus pulposus was anterior and away from the posterior disc margin.
They concluded that moving the cervical spine into extension could be clinically valuable in the case of cervical disc problems.
At Dynamic Disc Designs, we have seen what these researchers have seen! When our handcrafted models (with an annulus and nucleus) are moved into extension, the nucleus can been seen to move anterior. In our lumbar models, the clear L4 vertebra of our Professional LxH Model allows full migration visibility of the nucleus pulposus. This is helpful in the clinical explanation of treatment targets for patients with intervertebral disc problems.
- Kim YH, Kim SI, Park S, Hong SH, Chung SG Effects of Cervical Extension on Deformation of Intervertebral Disk and Migration of Nucleus Pulposus. PM R. 2016 Sep 6. pii: S1934-1482(16)30905-4. doi: 10.1016/j.pmrj.2016.08.027. [Epub ahead of print ↩