"The human body's 'joint music' is a natural, normal thing."
So says Susan Saliba, a professor in the University of Virginia's School of Education and Human Development and co-director of the Exercise and Sports Injury Laboratory.
More:
Q. What makes your joints crackle, crinkle, and clatter?
A. There are two causes of snapping and popping.
One is like cracking your knuckles. There are microscopic gas bubbles within the synovial/joint fluid, and when the joint is 'distracted,' the suction creates a negative pressure, and the gas bubbles consolidate and 'pop.'"
Lots of joints pop. Often, it relieves pain and pressure around a joint temporarily. If you've ever baked a cake, you gently slam the pan to consolidate and pop the gas bubbles to make the cake smooth, a process called cavitation. Cavitation in the joint takes pressure away from joint receptors, and almost immediately there is a sense of relief.
The second cause of joint noise is friction. We're designed to have bursae — synovial fluid-filled sacs — over bony projections to allow gliding and sliding. But just like a blister, frictional overuse makes the structure produce more fluid, and sprains and strains make tendons and bursae swell.
We may feel the friction but we keep going, and the bursa swells, and now there's limited space. It may not hurt after it heals, but the clicking and popping often remain.
Q. If you have osteoarthritis, should you keep exercising?
A. Osteoarthritis is not a reason to stop moving. It's a reason to get moving, or keep moving, so that overall health is maintained and the joint fluid can do its job to reduce friction and provide nutrition to the surfaces.
Often, we're told to pay attention to pain and avoid it, so many people just shut down. This approach can result in a devastating loss of motion, pain, less mobility, worsening strength, poorer health as a result of decreased mobility, and weight gain. Millions of people are in this situation, and general health decline is often associated with this cascade of events.
Q. Are there specific exercises or programs that help keep joint flexible?
A. Anything you like. Yoga, walking, hiking, swimming: movement is fundamental.
Specific directed exercise, biomechanical evaluation, and coaching help guide a person through recovery from an injury. Athletic trainers and physical therapists are skilled at this and can suggest modifications that are well tolerated and will help restore joint fluid.
Even if movement doesn't prolong your life, it will definitely improve its quality.
