What Are Cracking Joints?

Cracking joints are bodily joints, often in the knuckles, spine, knees, and hips, which make a popping sound when they are moved or otherwise manipulated. Some medical researchers believe that cracking joints are caused by a change in joint fluid pressure, while others suggest that the cracking noise may result from the movement of muscles, tendons, or other joint components against one another as a joint is manipulated. Often, people purposely cause cracking joints, either as a simple habit or to seek temporary relief from joint discomfort. Contrary to popular belief, intentionally cracking one’s joints does not appear to cause long-term joint problems.

Many medical experts believe that the phenomenon of cracking joints is related to the pressure of the fluid that naturally surrounds the joints. When a joint is stretched, the joint fluid is temporarily given more space, and the pressure which is being exerted on the fluid drops as a consequence. This change in pressure can cause bubbles to form and then pop, resulting in an audible crack.

Other medical researchers have suggested that cracking joints occur when two or more of the components of a joint move against one another. A joint is made of many parts, including bone, ligaments, tendons, cartilage, and muscles. When two or more of these parts are pushed against one another, a cracking sound may be produced.

Often, people purposely cause cracking joints. Some crack their joints, particularly their knuckles, simply out of habit. In some cases, however, people intentionally crack their joints to temporarily relieve discomfort in the area. This intentional cracking may be performed by the discomfort sufferer himself. Alternatively, the discomfort sufferer may visit a chiropractor, osteopath, or physical therapist to have his joints professionally manipulated and cracked.

A great many people are familiar with the belief that repeatedly cracking one’s joints, especially the knuckles, can cause those joints to develop arthritis. There is no medical evidence to support this claim, however. In fact, some research shows that joint cracking may temporarily improve mobility by loosening the joints and causing them to feel more flexible. On the downside, however, some researchers believe that prolonged cracking of the joints in the hand can lead to a weakened grip.