How is the intervertebral disc affected by some treatments?

Several treatments used by doctors of chiropractic and other health professionals are thought to generate beneficial physiological effects on intervertebral discs. Traction (or decompression) high-velocity low-amplitude (or thrust) spinal manipulation, and various forms of mobilization (or non-thrust manipulation) have been described as treatments that reduce nerve root compression and/or intervertebral disc protrusion as a primary therapeutic mechanism. However, scientific evidence largely suggests these treatments do not reduce nerve root compression or disc protrusion. So where does that leave us?

A recent systematic review published in the journal Physiotherapy and Practice reports the available scientific evidence for physiological changes in intervertebral discs following traction (intermittent and static), thrust and non-thrust manipulation.(1) Evidence suggests each of these treatments influence disc physiology by improving water diffusion. In so doing, short-term disc height may be marginally improved. However, the most measurable physiological effect is the imbibition of fluid into and out of the disc, sometimes resulting in a net fluid gain, which can potentially slow degenerative change and dilute inflammatory elements causing pain. This evidence could match your current ideas on how these treatments affect the disc. If the evidence challenges your ideas, then you may need to rethink how you explain these treatments to patients and use them to facilitate clinical benefit. Either way, keep a watchful eye on emerging evidence to inform us further about how these treatments influence physiology.

Reference List
(1) Mitchell UH, Helgeson K, Mintken P. Physiological effects of physical therapy interventions on lumbar intervertebral discs: A Systematic Review. Physiother Theory Pract 2017 Jul 17;1-11.