SUMMARY: If you often crack or pop your neck yourself, it probably means that the joints are hypermobile. The ligaments are a bit lax so the joints move a little more than they should. In response, the muscles tighten up to stabilize the joints. This makes your neck feel tight and makes you want to crack it. When you do that, the muscles are momentarily stretched, they relax somewhat, and you feel better for a while. But when you crack your neck you also stretch the loose ligaments further which makes the muscles tighten up again. It’s a vicious cycle.
(Hypermobility should not be confused with clinical instability.)
What’s the Real Problem and What Can You Do About It?
The scenario goes something like this: You’re under a lot of stress and your neck feels tight. This morning you drove all over town meeting with clients. You were late for a meeting and the client left before you could get there. The next client stood you up. Now you’re back at the office staring at your computer screen. Your company just upgraded and you can’t get the program to do what it’s suppose to do. Your neck feels like it’s in a vice. Without giving it much thought you put one hand on the back of your head, cup your chin in the palm of the other hand, and twist sharply. Your neck emits popping sounds like a string of firecrackers on Chinese New Year. You twist in the other directions, hearing and feeling another series of cracks. Aaahh … that’s better! But soon the stress mounts again, tension builds, and you find yourself twisting your neck again. Each time the results are less satisfying. By the end of the day you feel like you’ve been through the ringer, and so does your neck.
If you are a chronic neck cracker you are probably doing more harm than good. What happens when someone repeatedly manipulates his or her neck? In order to understand how this can be harmful, it first helps to have some knowledge of normal joint function. Here are the fundamentals:
1. Joints move. Okay, you knew that already. The point is that your spine is made up of many vertebrae, each of which articulates (forms joints with) the vertebra above and the vertebra below. The joints in the spine do not have as great a range of motion as do the larger and more mobile joints of the shoulders, elbows, hips, and knees, but because there are 24 moveable segments in the spine, the combined motion of these joints allows us to bend forward and touch our toes (some of us, anyway), look over our shoulders to back the car out of the driveway, and perform nearly all of our daily activities. Without spinal motion people would look like the Tin Man before he found his oil can. Joints move.
2. Normal joints have normal motion. This may sound like another no-brainer, but neck-crackers have a problem with normal joint motion. There are four phases of motion: active, passive, paraphysiologic – where the “pop” occurs during manipulation – and sprain – where ligaments are injured. This is illustrated in the figure below.
Active motion is the range in which a person can move a joint unaided. For example, wave your index finger up and down. That’s the active range of your second metacarpophalangeal joint (the big knuckle). Now use the fingers of your other hand to move the index finger up and down passively. The passive range of motion should be greater than the active range. Joint mobilization, a treatment used by physical therapists and less commonly by chiropractors, is movement within the passive range of motion.
3. Why joints pop. Movement through the paraphysiologic zone, the Twilight Zone of joint motion, occurs when the passive range is exceeded but before actual damage can occur. Paraphysiologic motion involves the “play” of a joint, not just further passive motion. This springiness you feel in your knuckle when you gently tug on a finger or push the finger backward to the endrange of passive motion is there because the ligaments have a little give built into them. In the paraphysiologic zone the surfaces of each bone – which don’t actually quite touch in a normal joint – move apart slightly further. A sudden and quite temporary vacuum occurs which is just as suddenly filled by gas which has been, up until that moment, saturated in the joint fluid. A popping or cracking noise is produced. This exchange of gas and fluid is called cavitation. It is similar to popping your cheek with your finger; when you push your fingertip out of your mouth quickly, air rushes in to the space suddenly created and makes a pop!
4. The bad news for “self-manipulators.” If you are a chronic neck-popper, you are very likely stretching the ligaments which support and stabilize your neck joints. Stretched ligaments result in a condition called hypermobility in which the joints lose their natural springy end play. To someone skilled at feeling joint motion, like a chiropractor, this loss of springiness can be detected. It is sometimes jokingly referred to as “floppy disc syndrome,” although the discs in the neck are not directly affected. As the ligaments become more lax, the small muscles that connect one vertebra to the next become tight. They have to work harder to make up for the loss of stability due to the lax ligaments. This makes your neck feel tight. As the muscle tension builds and your neck becomes more and more uncomfortable, you feel the urge to manipulate your neck. CRACK! The muscles are stretched, they relax, and you feel some relief. Of course, this manipulation also stretched those already loose ligaments, and the vicious cycle starts over again.
Hypermobility can be congenital (i.e., hereditary) or acquired. Teens tend to have hypermobile spinal joints. This is normal and will usually resolve as the skeleton and supporting tissues finish growing. However, if neck cracking becomes a habit, then the problem can continue into adulthood. Clinical evidence suggests that hypermobile spinal joints become arthritic at a faster rate than normal joints. Hypermobility can also result from injuries such as whiplash, or it can be self-inflicted. Some popping in the back or neck occurs spontaneously with movement and may be normal.
Treatment: Chiropractors treat hypermobility with strengthening exercises. If the ligaments are weak and the muscles have to work harder, they will be less tense if they are stronger. Strong muscles don’t have to work as hard as weak muscles, so there is less tension. Hypermobility is also treated with spinal adjustments, a form of manipulation. Although this would seem to be contradictory, sometimes hypermobility can be a compensation for restricted or fixated joints elsewhere in the spine. The adjustments are given only to these joints, not the hypermobile ones.
Of course, the best thing to do is to STOP POPPING YOUR NECK. That’s it. Just don’t do it. Most people who “go cold turkey” will feel worse for a time. But even if no other treatment is given, you will probably feel much better after two or three weeks.