*A chiropractic adjustment is a powerful thing and can work to help your body in many ways,
such as influencing biochemical changes, restoring motion/movement to a joint where
motion/movement is lacking, increasing muscle activation, promoting healing, reducing the
likelihood of injury or reinjury, and more. For today, we will focus on how a chiropractic
adjustment can help bring immediate(ish) pain relief mechanoreceptor stimulation!
WHY IS THERE PAIN IN THE FIRST PLACE?
I may use a couple of strange words coming up, so check out the parenthesized note right after a word where I’ll do my best to explain it! Here’s the first: Panjabi’s Control Triad (three-way communication between our brains, our muscles, and our joints and ligaments). The premise behind this is that there is a triad of communications within the body with regards to the musculoskeletal system and the central nervous system (CNS for short, this refers to our brain, brainstem, and spinal cord). The three legs are the CNS, the muscles (the active portion), and the joints and ligaments (the passive portion, acted on by the muscles). Our brains establish movement patterns based on the proper deformation of these other tissues. However, whenever there is a restriction/fixation within the spine (or any joint really), leading to a lack of movement, the communication between the active portion (the muscles) and the passive portion (joints and ligaments), and then the communication between those two subgroups and the CNS, becomes skewed. This can lead to something known as dysafferentation (simply a disruption in the “normal” ratio of pain to mechanoreceptive information that is sent from our bodies to our brains). In this, mechanoreceptor input decreases (this is the information that is sent to our brains that tells us when/where we are being touched or affected by something, sensing movement of joints, etc., for the sake of this explanation, just understand that this is a stimulus being sent to our brains that is not pain), while nociceptive input (pain) increases. I know this is a little dense, but it will help you understand chiropractic if just a little bit more…KEEP READING.
WHY DOES DYSAFFERENTATION MATTER?
Mechanoreceptive/non-painful stimulation travels to the brain via a different path than painful
stimulation. Mechanoreceptive stimulation travels to the brain through nerve tissue known as A-beta fibers, while pain travels to the brain through nerve tissue known as A- delta and C fibers. The names of these are not super important, just realize that they travel to the brain separately. A-beta fibers travel to the brain quicker than A-delta and C fibers do. This then means that mechanoreceptive/non-painful stimulus reaches the brain faster than painful stimulus does. To better understand this process, I want you to imagine that there are two trains traveling to the same location. The first train is carrying non-painful stimulus, the second train is carrying painful stimulus, and they are both traveling to brain station. The first train is traveling faster than the second train. So, because the first train makes it to the station first, it inhibits the second train from reaching the station. Mechanoreceptive/non-painful information makes it to the brain faster than painful information does, thereby inhibiting the perception of pain! So how does chiropractic fit into this equation? Let’s tie it all together!
HOW CAN CHIROPRACTIC HELP?
There are a ton of different types of receptors within our body that receive different types of
information and send it to our brains to be processed and responded to. Some receptors sense pain, some sense vibration, some are responsible for proprioception, some sense light touch, and some sense mechanoreceptive information like pressure or distortion (these are the ones we are interested in right now). These receptors that sense pressure/distortion/non-painful stimulus are the ones that travel faster to the brain than pain (also the ones that their input decreases as a result of dysafferentation), and therefore inhibit the perception of pain. Well guess where there are a TON of mechanoreceptors in your body: your spine! All the little joints in your spine are chock-full of these mechanoreceptors/joint receptors that are stimulated as a result of a chiropractic adjustment. So, when we get adjusted, a wave of mechanoreceptive information races to our brains, dampening the noxious stimulus, thus reducing our pain! Awesome stuff if you ask me.
-Mechanoreceptive/non-painful information (telling us about physical pressure/distortion) travels to our brains on a different path than painful information does
-Mechanoreceptive/non-painful information travels to our brains faster than painful information does, having the potential of inhibiting/blocking our perception of pain
-There are a ton of different receptors in our bodies that receive different types of information
and send it to our brains
-The joints in our spines are FULL of the types of receptors that receive and transmit the faster mechanoreceptive/non-painful stimulation
-These receptors in our spines are stimulated as a result of an adjustment, sending a wave of information to our brains, dampening the perception of pain = pain relief
Clark, Brian C., et al. “Neurophysiologic Effects of Spinal Manipulation in Patients with Chronic
Low Back Pain.” Medicine & Science in Sports & Exercise, vol. 43, no. Suppl 1, 2011,
Hoffman, J., and P. Gabel. “Expanding Panjabi’s Stability Model to Express Movement: A
Theoretical Model.” Medical Hypotheses, vol. 80, no. 6, 2013, pp. 692–697.
Liebenson, C. Rehabilitation of the Spine: a Practitioner's Manual. Lippincott Williams &
Melzack, R., and P. D. Wall. “Pain Mechanisms: A New Theory.” Science, vol. 150, no. 3699,
1965, pp. 971–978.
Panjabi, Manohar, et al. “Spinal Stability and Intersegmental Muscle Forces.” Spine, vol. 14, no.
2, 1989, pp. 194–200.
Pickar, Joel G. “Neurophysiological Effects of Spinal Manipulation.” The Spine Journal, vol. 2,
no. 5, 2002, pp. 357–371.
Seaman, David R., and J.F. Winterstein. “Dysafferentation: A Novel Term to Describe the
Neuropathophysiological Effects of Joint Complex Dysfunction. A Look at Likely
Mechanisms of Symptom Generation.” Journal of Manipulative & Physiologic
Therapeutics. 21(4): 267-280. (May) 1998.