Snapping or Cracking Joints a Cause for Concern?

Written by Chase Katich, Walton Physical Therapy

Popping knees and cracking joints can be quite disturbing, and often times a cause for concern. But more often than not these noisy joints have a bark that is far worse than their bite. These sounds can persist for years without a real problem ever developing, and sometimes the exact cause is hard to detect and explain. But rest assured, usually there is no damage being done to the joint during these events.

Most joint sounds are typically caused by nitrogen gas bubbles, soft tissue such as tendons and ligaments, or arthritis. It is very common for gas bubbles to form in the synovial fluid that bathes our joints. When the joint is rapidly stretched, the gas is released causing a pop or crack, while also forming a gas bubble. This is most commonly whats occurring when someone cracks their knuckles. The joint cannot be popped again until the gas returns into the synovial fluid.

Tendons and ligaments can also be a common cause of joint popping. When a particular joint moves the tendons and ligaments surrounding the joint also move and can become slightly displaced. A snapping sound may occur when the tendons or ligaments roll back into place over a bony prominence. A physical therapist can design a corrective exercise program to assist with normalizing joint alignment, tracking, and flexibility which may reduce or eliminate this form of popping.

Lastly, arthritic joints can cause a grinding noise when the rough joint surfaces come together during movement. This sound is often referred to as crepitus and can be quite disturbing. This form of popping or cracking is least amenable to conservative treatment. Some patients report benefits from a joint supplement such as glucosamine or chondroitin, but the current literature is still not conclusive.

So is a popping or cracking joint harmful? While not totally normal, as long as there is no pain associated with these joint sounds, they are usually harmless. However, if pain does become present with a cracking or popping joint then you should be further evaluated by a health care provider to understand the underlying cause.