Cracking of the joints is a normal phenomenon of the body. However, it may become a worrisome symptom if it is accompanied by pain. Painful cracking of the joints may be caused by one of two things: damage to the joint from arthritis or a tear in the connective tissues of the joint. Pain that accompanies cracking of the joint should never be ignored and warrants an investigation by your doctor.
Joint Anatomy
To understand why joints make cracking noises or sensations, you will first need to understand basic joint anatomy. A joint is a location in your body in which the ends of two bones come together -- for example the knee, shoulder or hip. The joint itself is surrounded by a joint capsule, which is a membrane or sac that seals off the joint space. The joint capsule is lined with a synovial membrane that produces a type of fluid known as synovial fluid, which acts to lubricate the joint. The ends of the bones are lined with a soft connective tissue called cartilage that protects your bones and allows them to glide smoothly over one another. Other types of connective tissue such as tendons, ligaments and menisci are found within and outside the joint space and act to stabilize the joint.
Normal Cracking of Joints
Cracking and popping noises or sensations in your joints are normal and occur naturally from time to time. It is necessary to distinguish this from pathological causes of cracking joints. There are several explanations for this phenomenon. One is that gases such as nitrogen in the synovial fluid form bubbles when the joint is stretched or pulled. We have all seen or experienced this when a person cracks their knuckles. Another explanation is that sometimes tendons or ligaments move out of their position when the joint is moved, and then snap or pop as they are moved back into place. An example of this is when you cracks your neck.
Abnormal Cracking of Joints
Pain that accompanies cracking of the joint is abnormal and a sign of injury to the joint. This is most commonly seen in individuals with arthritis. Arthritis is a condition in which the cartilage in your joint becomes damaged. As the cartilage becomes worn away, the bone is exposed to the joint space. As a result, the bones create a cracking sensation or noise as they rub against one another during movement. Individuals with arthritis typically complain of pain, swelling and decreased range of motion of their joints in addition to cracking. Another less common cause of painful joint cracking is injury to the connective tissues within or surrounding the joint capsule. This may include injury to the ligaments, tendons or menisci. These injuries present with a sudden pop during exercise as the connective tissue is torn and then pain afterward.
What to Do
Cracking that is accompanied by pain, swelling or loss of motion is abnormal and warrants a call to your doctor. If you experience a sudden pop or crack and then pain, stop exercise immediately and seek medical attention. If you have arthritis and suffer from painful cracking of joints, the good news is that exercise can actually diminish symptoms of arthritis. According to the University of Washington, aerobics, stretching and strengthening exercises can help to reduce pain and stiffness as well as improve the stability of joints. However, you may need to change the types of exercise you do in order to garner these benefits. For example, if you suffer from osteoarthritis of the knees or back, you may have to choose low-impact forms of exercise such as bicycling and walking instead of high-impact exercise such as running.
