Intraneural fluid movement during nerve gliding
Neural root compression injuries are multi-factorial conditions that have been shown to accompany low back pain (LBP). They are often associated with structural alterations, neural ischemia and functional modifications of patients affected. Neurodynamic mobilisation (NMD) has been developed for clinical practice to normalize compressive, frictional and tensile forces commonly related to functional movement. Despite the clinical dissemination of NDM, the underlying mechanism for positive results following its application is unknown. With this in mind, the authors of the present study sought to assess the intraneural fluid dynamics in nerve roots with repetitive NDM. When performed on unembalmed cadavers, NDM was to shown to produce a significant increase in longitudinal fluid dispersion in lumbar nerve roots.
The fourth lumbar vertebra of seven unembalmed cadavers was exposed bilaterally via posterior dissection, and the L4 nerve root was injected with dye solution just proximal to the ganglion expansion. Longitudinal dye spread was measured pre and post NDM exercises. Experimental mobilization consisted of 5 minutes of repetitive straight leg raise (SLR).
Intraneural edema has been shown to be a common response to nerve injuries. Due to the lack of lymphatic vessels in the nerve endoneurium, management strategies geared toward restoring swollen nerves to baseline have begun gaining popularity in an effort to combat the complexity of neropathic pain. Fluid movement resulting from reciprocal transverse narrowing and intrafasicular gliding was shown to be significantly greater (0-2.6mm) in injected lumbar nerve roots when compared to controls. Considering these findings, the present study offers encouraging results that NDM can physically alter the fluid dynamics in lumbar nerve roots. Therefore, it can be used as a treatment approach towards low back and neuropathic pain.
> From: Gilbert et al., J Man Manip Ther 23 (2016) 239-245(Epub ahead of print). All rights reserved to Taylor & Francis. Click here for the Pubmed summary.