JOINT MUSIC

Crunch, crackle, snap, pop. These are the sounds of jaws chewing raw veggies, hiking boots climbing mountain trails, truck tires driving over icy roads, or flames licking at the air from a raging bonfire. We expect these noises, like musical notes in a song, during these activities. In fact, we welcome them. But what about those times when the crunch, crackle, snap and pop come from your body when you lift an arm or leg, or when you bend over to pick up the newspaper? The noises are creepy, alarming, and certainly not expected. What is all that racket and, if it's not painful, should you be worried?

Most times, no. Sometimes, yes. How's that for a definitive answer? The real question is, how in tune are you with your body, and are these sounds it normally makes? Have you felt pain during these crackle and crunch episodes either in the past or present? Pain is always a sign that something is askew, so it's best to pay attention. Maybe understanding what creates these noises will help gauge your reaction to them.

Most joints in the body are the point of contact between two or more bones. To reduce friction at this contact, a slick material called articular cartilage covers the bone ends. The joint is then encased in a capsule containing a lubricant called synovial fluid. Often, a bursa - a gel filled fibrous sac - is present in the joint and acts to cushion impacts received at the joint. Ligaments secure the bones at the joint, and the joint is then powered by muscle and tendon groups secured to the bones.

The crackle, crunch, snap and pop of the knees and ankles, for example, can be the tendon returning to its original position after shifting and moving slightly out of place during joint movement. Ligaments also tighten during movement which can make a cracking sound. Additionally, arthritic joints create rough surfaces when its smooth cartilage has been worn away. Connective tissue moving across this rough terrain can also add to the sound effects.

The synovial fluid in the joint contains the gases oxygen, nitrogen and carbon dioxide. When you pop or crack a joint (such as the knuckles), you stretch the joint capsule. Gas is rapidly released, which forms bubbles. Bubbles pop.

The bony spinal column is an arrangement of vertebrae and ligaments called facets. Slight misalignment that does not impair either the intravertebral disks or the surrounding muscle can also cause a cracking sound upon movement.

The rule of thumb is this: the body's chamber music is normal. If, however, pain resonates from the chamber where the music is piped out of, it's time to see your doctor. If you simply make sounds during certain movements, but you're not feeling pain either during or after, then it shouldn't worry you. The sounds - well - are not always the easy-listening type of music. That may be the hardest part to endure. Always, though, if you are concerned, get answers from your medical professional. Otherwise, tune in to what is your unique sound, and keep moving to the music.