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All About Chiropractic Adjustments


The chiropractic adjustment is the most commonly administered treatment option by chiropractors and patients often wonder what happens when this procedure is performed. Fear not, this short primer is here to give you comprehensive answers in an easy to understand manner. 

Chiropractic adjustment being performed

The Pop.

Let's start with the most obvious phenomenon of a chiropractic adjustment or joint manipulation. If you've ever cracked your knuckles or fingers, you are well aware of the noise that is generated. This noise also occurs in free-gliding joints of the body such as those in the spine when they are stretched far enough apart during an adjustment. While it used to be mysterious as to what causes the sound, research has confidently identified the cause of this as gas bubbles. Our joints are encased by ligaments where a fluid inside called synovial fluid bathes and lubricates the joint surfaces to reduce wear and tear from movement. When a joint is stretched far enough apart, a vacuum forms within the fluid due to the sudden increased space and dissolved gasses in the synovial fluid coalesce to form a bubble which causes the pop. If that sounds confusing, don't worry, below is a great short TEDed video that illustrates it very well along with a video of a real time MRI showing a knuckle being cracked.

Is It Safe?

After watching the video above you may now be asking yourself if chiropractic adjustments are safe. While no form of treatment is without risk, chiropractic adjustments are generally a very safe procedure. Chiropractors in the US are all nationally board-certified and have years of training and practice to ensure that you receive the correct treatment in the most comfortable manner possible. The most common question that new patients have is if a chiropractic adjustment or spinal manipulation is safe in the neck because of what they may have heard. Please see our Neck Pain section for the discussion about cervical manipulation safety.


Patients sometimes wonder about self-manipulation and ask about cracking their own fingers or using a foam roller on their upper back to release joints. Most of the time, these two cases are not a big issue, but beyond that it is ill advised to perform any other form or method of self-manipulation to the spine. One reason is that you are unable to fully relax postural muscles supporting the area you are trying to target. This may lead you to inadvertently pull on a muscle that isn't relaxed or is guarding due to pain, leading to further irritation to the area bothering you. The other reason is that you are not able to optimally or safely position and mobilize the joints you are trying to target placing too much stress or torque on a joint. Patients that describe performing self-manipulation are also usually mobilizing the joints that are already mobile instead of the ones that need it, setting up possible instability at a joint if it is chronically stretched over and over. If something is bothering you, do yourself a favor and seek a professional.

Effects Of The Adjustment.

While the procedure is used to provide pain relief and restoration of motion, what is happening that causes the relief that patients feel? You may often hear that an adjustment is done to free "pinched nerves" that are causing your pain, but that is an oversimplification to many possibilities that may be causing your pain. Below are some structures that may be causing neck and back pain and what spinal manipulation or spinal mobilization may be doing to relieve it.

Synovial Meniscoids

The synovial joint has been attributed to some causes of spinal joint pain. Particularly the cause of that "pinched" feeling that is usually associated with seizing neck and back pain. The encapsulating tissue that surrounds the synovial joint has protrusions called meniscoids that extend part way into the joint to help cushion and stabilize the joint. They are similar to the menisci of the knee as they function similarly. It is thought that they occasionally lose their position and become entrapped between the edge of a joint surface and the edge of the joint capsule causing pain, local muscle spasm, and consequently joint locking. The reason is because these meniscoids have pain receptors inside them. Spinal manipulation is thought to stretch the encapsulating tissue such that the meniscoid is freed from entrapment allowing it to return to its normal position arresting pain and restoring normal motion.

Synovial fold illustration

A. Joint in normal position, B. Joint at end range of motion with meniscoid drawn out, C. Joint returns to normal position with meniscoid becoming bunched and entrapped.

Spinal Discs

The spinal discs are another structure that can be a possible source of joint locking and pain. Our spinal discs are composed of two parts: an outer weaved fibrocartilaginous layer that resists shear and torsional forces and a middle gel-like cushion that resists compressive forces. The outer third of the disc has pain receptors and irritation or injury to the outer part may cause pain making it difficult to be in certain positions. Examples of this may be bulging or a tear from chronic poor movement patterns. The purpose of spinal manipulation, spinal mobilization, and even some exercises are an attempt to reduce loads to the discs.

Spinal disc injury
Inner Disc
Outer Disc
Herniated Disc
Nerve Root
Herniated Disc

In the worst case of a disc injury, the outside of the disc ruptures and allows the middle gel to escape where it can push against a nerve root causing extreme pain along with feelings of numbness, tingling, or weakness in the extremities. This injury is commonly known as a disc herniation and is a case in which a nerve could truly be pinched. In practice, it is a very uncommon injury, but bending and twisting motions are known to put you at risk. The purpose of spinal manipulation and mobilization is to influence the positioning of the nerve and inner disc material such that irritation can be reduced while the patient heals.​ In some cases, steroid injections or surgery by a medical doctor may be necessary for recovery.

Facet Irritation

Largely based on clinical examination, this is believed to be a common cause of pain in the spine, especially the lumbar spine. Poor mechanics may force the lumbar spine into excessive extension (backwards bending), leading to compression of the facet joints causing pain. This is why some individuals with low back pain often feel temporary relief from bending forward to stretch their low back. This pain can sometimes refer into the buttocks or legs mimicking sciatica. Spinal manipulation or mobilization provides relief by opening and "decompressing" the joints, but coupling it with exercises may be more effective at providing longer-term relief.

Lumbar Facet Joint
Facet Joint
Lumbar Hyperextension
Facet Joint

Neurological Effects

Lastly, pain relief in the spine may also be neurologically mediated. Some studies suggest that adjustments may stimulate certain types of nerve receptor endings that can drown out the impulse of the ones that are responsible for communicating pain to the brain. If you've ever been hit and immediately rub the area to try to soothe the pain, this is the same phenomenon. It is also one of the effects by which kinesiology tape works. Another possible neurological mechanism is that the stimulation of nerve endings around a joint​ or the stretching of muscle tendons during an adjustment will interrupt local muscle spasm, bringing relief.

If you're looking for chiropractic care in Kirkland, Dr. Frank Wen at Integrity Chiropractic has your back. 


•      Bergmann, T. F., & Peterson, D. H. (2011). Chiropractic technique: principles and procedures. St. Louis, MO: Mosby/Elsevier
•    Evans D. Original article: Mechanisms and effects of spinal high-velocity, low-amplitude thrust manipulation: Previous theories. Journal Of Manipulative And Physiological Therapeutics [serial online]. May 1, 2002;25:251-262. 

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