Whether you have developed the habit of cracking your knuckles or you have tried to make someone else break their habit, many of us have encountered the loud popping noise of this action at some point. Some of us have even heard that cracking knuckles can cause harm and lead to long-term health concerns such as arthritis.
But is it actually harmful to crack your knuckles?
Jordan Adams, clinical coordinator of the physical therapy assistant program, said that the desire to crack or pop joints, including knuckles, can occur when the bones in the joint have left their optimal position due to muscle imbalances, pathology, damage or joint tightness. When this occurs, someone might experience some discomfort or pressure. Cracking the joint releases the gases in the joint with the aim of reaching that ideal position.
When these gases are compressed, they make a popping sound, making the person “crack” their knuckles.
People often enjoy cracking their knuckles because it relieves pressure or relieves anxiety.
Adams said research has displayed that there is no correlation between cracking joints and higher risks of arthritis. In fact, physical therapists (PT) can actually use cracking joints to treat joints.
“From a PT standpoint, we call cracking a high velocity thrust mobilization, or manipulation, and there are benefits from having a skilled professional such as a PT perform these movements when indicated,” Adams said. “In physical therapy, a manipulation of a joint would then be stabilized through therapeutic exercise in order to improve function at the joint overall.”
While cracking joints can lead to harm — dislocations and injuries to tendons — in extreme circumstances, Adams said cracking knuckles regularly should be safe most of the time.
“If the cracking of the joint does not produce pain, there should not be concern,” Adams said. “Cracking that produces pain could be indicative of an underlying pathology or dysfunction.”
Dr. Stephen Runyan, associate professor of biology, corroborates this sentiment. Runyan even said cracking knuckles can be beneficial for the body because it contributes to fluid movement and blood flow.
“Our cartilage in the joints acts like sponges and it soaks up this fluid in the joints that contains wastes as well as blood that’s bringing in new nutrients, so the more we move our joints with exercise, actually the more it’s getting rid of waste and the more it’s bringing in the nutrients,” Runyan said. “So if you’re cracking your knuckles and you’re moving them more, it might even be potentially beneficial.”
Research studies have supported that cracking knuckles has no clear correlation with arthritis. In fact, one doctor studied his own hands for proof of this.
“One of the most convincing bits of evidence suggesting that knuckle cracking is harmless comes from a California physician who reported on an experiment he conducted on himself,” reads a Harvard Health Publishing article. “Over his lifetime, he regularly cracked the knuckles of only one hand. He checked X-rays on himself after decades of this behavior and found no difference in arthritis between his hands.”
While not from cracking knuckles and other joints, arthritis can stem from other sources within people’s control. Runyan said the most common form of arthritis, osteoarthritis — or “wear and tear” arthritis — can occur due to lack of use, which leaves tissues without a regular flow of nutrients and deteriorates the cartilage at the joint. It can also take place when joints become imbalanced, with one bone wearing down more than the other.
Another common type of arthritis, rheumatoid arthritis, is actually an autoimmune disorder in which the immune system attacks the synovial membrane at the joint, deteriorating the cartilage at the end of the bone.
To avoid joint issues such as arthritis later in life, Runyan recommends exercise and movement, focusing on strengthening muscles on both sides of a joint to ensure balance and stability.
“The strength around the joint will improve the likelihood that you won’t have joint disorders,” Runyan said. “The strength of the muscles surrounding the joint is really important to help the bones are aligned properly.”
If you find yourself cracking an area of common discomfort to relieve pressure, Adams recommends seeking out a PT to help stabilize the region.
