Have you ever cracked your knuckles and had someone tell you that you’ll end up with jointless fingers when you grow old? That may sound a bit ominous, but the odd satisfaction of popping knuckles is something you cannot deny. Some find it fun, while others find it somewhat annoying. Now, what causes this clicking sound, and is it as dangerous as we were told, is something to ponder.
The ‘cracking’ of knuckles seems to be produced by increasing the space between finger joints. This causes gas bubbles in the joint fluid to collapse or burst. It is a bit like blowing up a balloon and then stretching the walls outward until it pops. The reason you can’t crack the same knuckle or joint twice right away is that it takes time for the gas bubbles to accumulate again in the joint.
Sounds quite interesting, right? Our joints can actually accumulate gas! However, it is vital to understand that cracking knuckles isn’t as dangerous as it seems.
What Happens When You Crack Your Knuckles?
To understand the science, you need to know what joints are made of. Your joints, like those in your fingers, are surrounded by a capsule filled with a lubricating substance called synovial fluid. This fluid reduces friction and helps the joint move smoothly.
When you crack your fingers, the joint space widens, lowering pressure and forming bubbles as gases come out of the joint fluid. When these bubbles burst, a popping sound occurs.
Is Cracking Your Knuckles Harmful?
Some concerns regarding it are addressed below:
Can cracking knuckles cause arthritis?
No, it does not cause arthritis. Multiple studies, including one by Dr. Donald Unger, who cracked only one hand’s knuckles for 60 years, found no difference in arthritis between both hands. There is no scientific evidence linking knuckle cracking to arthritis.
Can it weaken your grip or damage tissues?
Not exactly, but there are some considerations. Excessive, forceful cracking might irritate the soft tissues around the joints. In some cases, repetitive cracking may cause temporary swelling or reduced grip strength, but this is rare. Habitual cracking can stretch ligaments slightly, making the fingers feel looser over time. However, there is no solid evidence that regular, moderate knuckle cracking causes permanent harm.
Can it cause joint instability?
This occurs only in extreme or unusual cases. Aggressive manual manipulation or repeated, forceful cracking (especially pulling the joints sideways) may increase joint laxity. However, this is not typically seen with normal, everyday knuckle cracking.
Why Do Some People Feel Relief After Cracking Their Knuckles?
Relief comes from releasing joint pressure, making finger movement easier. Cracking knuckles also triggers a brief pleasurable neurological response, like stretching after sitting. This combination of physical and psychological rewards makes knuckle cracking a habit.
Why Do Others Find the Sound Displeasing?
The reaction is mostly psychological; for many, the harmless sound is linked to discomfort or pain, and some are sensitive to its suddenness.
Interestingly, studies show that people who do not crack their knuckles generally find the sound more irritating than those who do.
Should You Be Concerned?
Knuckle cracking is usually harmless, but you should seek medical advice if you experience any of the following:
• pain during or after cracking
• noticeable swelling
• stiffness that doesn’t go away
• loss of movement
• clicking or grinding not related to cavitation
These symptoms could indicate an underlying joint condition unrelated to cracking.
Other Mystery Noises
What about other sounds coming from the joints? Are those sounds also caused by gas bubbles?
The origin of most joint noises is a broad topic. The popping or cracking of knees when squatting is not fully understood. These noises may occur due to the kneecap rubbing against the bones below or a tendon sliding over an uneven surface.
However, if there is no pain, swelling, or other joint-related symptoms, these sounds are usually nothing to worry about. At present, there is no reliable way to completely eliminate them. Also, it cannot be said with certainty that these noises are caused by the same mechanism as knuckle popping.
Final Thoughts
The debate around knuckle cracking is more myth than fact. While the sound might not be pleasant to everyone, science stands clear: Cracking your knuckles is mostly harmless. If it helps relieve tension, go ahead, but maybe be mindful of your surroundings!
