Changes in biochemical markers following spinal manipulation-a systematic review and meta-analysis

As spinal manipulation is coming to the forefront of physical therapy practices it is vital to understand what effects we are creating. At this time it is clear to see the change in range of motion, pain and muscle force production during spinal manipulation. As we dive deeper we begin to see that there may be much more to spinal manipulation than meets the eye. In this study cited they identify what happens on a cellular level during spinal manipulation treatments. Below are the results of their findings.

"There was moderate quality evidence that spinal manipulation influenced biochemical markers. There was moderate quality evidence of significant difference that spinal manipulation is better than control in eliciting changes in cortisol levels immediately after intervention. There was also a low quality evidence that spinal manipulation is better than control at post-intervention in increasing substance-P, neurotensin and oxytocin levels. However, low quality evidence indicated that spinal manipulation did not influence epinephrine or nor-epinephrine levels. The current review found that spinal manipulation can increase substance-p, neurotensin, oxytocin and interleukin levels and may influence cortisol levels post-intervention."

The changes in these markers may account for the immediate effects after spinal manipulation. The effects that may be triggered as a result of this are... 

Substance P-The sensory function of substance P is thought to be related to the transmission of pain information into the central nervous system. This effect may be useful when dealing with 
chronic musculo-skeletal dysfunction that requires inflammatory properties to facilitate healing such as tendonosis. 

Neurotensin-It induces a variety of effects, including analgesia, hypothermia and increased locomotor activity. It is also involved in regulation of dopamine pathways. In the periphery, neurotensin is found in enteroendrocrine cells of the small intestine, where it leads to secretion and smooth muscle contraction. This effect may be useful when attempting to enhance proprioceptive neuromuscular facilitation.

Oxytocin-Affects emotional, cognitive, and social behaviors. This effect is commonly seen immediately after a manipulation as most patients will feel a sense of relief and excitement when a cavitation occurs. Many may dismiss this effect as a placebo, whatever your thoughts on this effect it is undeniable that it is present is an overwhelming amount of patients after a manipulation. 

Interleukin-Regulate cell growth, differentiation, and motility. They are particularly important in stimulating immune responses, such as inflammation. This effect may assist with starting a much needed inflammatory response to facilitate healing such as substance P.

The are new and exciting studies coming out constantly about the role spinal manipulation can have on patient care. I believe spinal manipulation should be common practice for physical therapist given the overwhelming evidence to support its use. The ability to utilize extremely beneficial techniques in very short period of time will be an invaluable asset as we continue to have less and less time without our patients. 

Kovanur-Sampath K1Mani R2Cotter J3Gisselman AS2Tumilty S2. Changes in biochemical markers following spinal manipulation-a systematic review and meta-analysis.  2017 Jun;29:120-131. doi: 10.1016/j.msksp.2017.04.004. Epub 2017 Apr 5.
https://www.ncbi.nlm.nih.gov/pubmed/28399479