Most of us have experienced the popping of a knuckle or a joint in the spine. However, few people understand what is actually occurring in the joint. Most of the joints in our body are filled with a fluid called synovial fluid. This fluid acts a lubricant to the joint surfaces and provides nutrition to the cartilage. One of the many components of the synovial fluid is nitrogen. Nitrogen is capable of being present in either a gas or a liquid state. When a joint is stretched a cavitation, or pop, can occur causing the nitrogen gas bubbles to form in the synovial fluid. When a joint cavitates many people experience a sense of relief. This is due to the fact that a cavitation triggers the release of endorphins, which are the body’s natural pain killer.
Many of our patients with unstable spines have been chronic “self manipulators” that constantly pop their own back or neck. This urge to self manipulate can actually be a type of chemical dependence due to the endorphin rush. The risk of continually doing so is that when the nitrogen gas forms in the joint it causes the joint to swell. If the joint is stiff, this can be beneficial to aide in stretching. However, if done over and over again this can lead to too much mobility and eventually instability at the spinal segment. Many people will state “my back needs to pop.” While they may be feeling tight, self manipulation lacks the ability to isolate a tight segment. If this person forcefully twists their spine the most likely segment to cavitate will not be the tight one, but one that is already very mobile. Over time this becomes the weak link in the chain and pops easier and easier. When a joint in the back is too mobile it forces the muscles in the area to work much harder to provide support. When these muscles get overworked, the back gets sore, and the person feels once again that they need to pop their back. The temporary relief provided by the endorphins makes the person think that they have successfully fixed the problem when in fact they have merely restarted the cycle.
While joint manipulation can be a useful tool in the hands of a skilled therapist, self manipulation lacks the ability to diagnose and treat the correct joint. Once an instability develops the proper course of treatment is a stabilization program to the affected region. While this can have a good outcome, the much easier solution is to avoid self manipulation to prevent the problem from developing in the first place.
Submitted by Joe Schmersahl, PT