Many people ask me what exactly is going on when a chiropractor manipulates a joint. We are all familiar with the crack sound that happens between joints. Sometimes it happens when you arch backwards, extend your knuckles and of course, when your chiropractor plays rough and tumble with you.

Joints are tightly wrapped in ligaments forming an almost, airtight capsule around the joint. When the articular surfaces of a joint are separated, but still within their natural range of traction, there is a large reduction in pressure as compared to atmospheric pressure. This causes gases to escape from the synovial fluid within the joint forming a bubble; a momentary vacuum. Synovial fluid is the substance that provides for a friction free surface and nourishes the joint. The contents of this vacuum are water vapour, nitrogen, oxygen, and carbon dioxide. Eighty percent of the contents is carbon dioxide. The bubble quickly collapses causing the ‘crack’ sound.

Thus, the crack sound is more accurately described as a popping sound. Rest assured, there is no cracking of bones occurring during spinal manipulation. A crack would imply a fracture and chiropractors are expertly trained in how to manipulate joints safely, without risk of injury. People, understandably, often feel vulnerable in their chiropractor’s hands. They fear that manipulative treatment will involve the risk of having their neck snapped off or their back crushed.

Experienced chiropractors know all too well the real force required to injure a joint. Part of a chiropractor’s training involves many hours in anatomy labs where they study real human dissections. I recall from my own experiences observing the strength of the ligaments and muscles that bind the joints and remember thinking, “it would take an incredible amount of force to disrupt a spinal joint”.

Manipulation has a bad reputation amongst many people, and for no good reason. People might say, “but my chiropractor manipulated me once and it hurt.” The problem here is that the person is focusing on the procedure and not the outcome. For example, a person will endure a painful massage and think of it as beneficial. The same person may be nervous at the prospect of a manipulation which might be momentarily uncomfortable, but is likely to produce beneficial outcomes.

In my opinion, neither massage nor manipulation should be painful. Pain is highly subjective and people will have different thresholds, but essentially pain functions to alert us of damaging stimuli. Sometimes in physical therapy, the aim of treatment is to aggravate the injured site just enough to accelerate the healing response. The skill lies in the practitioner finding the balance between effecting a degree of discomfort rather than pain.

If you’ve been seeing a therapist for an injury, and you leave the practice in pain after each visit, I would question the value of that treatment. Having said that, remember that it’s entirely acceptable to wince and groan when you’re on the receiving end of a calf or glute massage. The best indicator of effective treatment is an improvement in your condition. Focus on the outcome, and if you’re unsure as to whether your therapist is in fact hurting or helping you, ask them to explain their approach or better yet, what you should expect to feel during a procedure.

*DISCLAIMER: This discussion does not provide medical advice. The information, including but not limited to, text, graphics, images and other material contained in this discussion are for informational purposes only. The purpose of this discussion is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read in this blog.