By SH Research-Reviewed by Adam Watts M.D.

Have you ever wondered why your knees make popping or snapping noises when you move them? This sound is called crepitus and it can have different causes. Sometimes, it is harmless and normal, but other times, it can indicate a problem with your knee joint. Here are some possible reasons why your knees pop sometimes and what you can do about it.

Air Bubbles

One common reason for knee popping is the release of gas bubbles in the synovial fluid, which lubricates the joint. When you bend or straighten your knee quickly, some of the bubbles burst and make a popping sound. This is similar to cracking your knuckles and it does not cause any harm or pain. It can happen to anyone at any age.

Another possible cause of knee popping is the movement of ligaments and tendons around the joint. Ligaments are tough bands of tissue that connect bones, while tendons are cords of tissue that attach muscles to bones. Sometimes, these structures can stretch slightly as they pass over a small bump on the bone and snap back into place, making a clicking sound. This is also normal and usually painless, unless there is inflammation or injury.

Ligaments and Tendons

Cartilage Damage

A more serious cause of knee popping is the damage to the cartilage that cushions the bones in the joint. Cartilage is a smooth, rubbery tissue that prevents friction and absorbs shock. However, cartilage can wear out over time due to aging, overuse, or injury, leading to osteoarthritis. Osteoarthritis is a degenerative condition that causes pain, stiffness, swelling, and reduced mobility in the joint. When cartilage is damaged, it can also break off and float in the synovial fluid, causing a catching or locking sensation in the knee.

One type of cartilage damage that can cause knee popping is a meniscus tear. The meniscus is a crescent-shaped pad of cartilage that acts as a shock absorber between the thighbone and the shinbone. A meniscus tear can happen when you twist or rotate your knee forcefully, such as during sports or accidents. A meniscus tear can cause a loud pop, followed by pain, swelling, instability, and difficulty moving the knee.

Another type of cartilage damage that can cause knee popping is chondromalacia patella. This is when the cartilage under the kneecap (patella) becomes soft and rough due to overuse or injury. This can cause a dull ache behind the kneecap, especially when going up or down stairs, squatting, or sitting for long periods. This condition is also known as runner’s knee or patellofemoral syndrome.

When to Worry

Knee popping by itself is not usually a cause for concern, unless it is accompanied by other symptoms such as:

• Pain
• Swelling
• Redness
• Warmth
• Tenderness
• Difficulty moving or bending the knee
• Instability or giving way of the knee
• Locking or catching of the knee

If you experience any of these symptoms along with knee popping, you should see a doctor for a proper diagnosis and treatment. Some of the possible treatments for knee problems include:

• Resting and avoiding activities that worsen the pain
• Applying ice packs to reduce inflammation and swelling
• Taking over-the-counter pain relievers such as ibuprofen or acetaminophen
• Wearing a knee brace or bandage to support and stabilize the joint
• Doing physical therapy exercises to strengthen and stretch the muscles around the knee
• Getting injections of corticosteroids or hyaluronic acid to reduce pain and improve lubrication
• Having surgery to repair or replace damaged cartilage, ligaments, or tendons

Vitamins for Healthy Knees

In addition to these treatments, you can also take some vitamins to help keep your knees healthy and prevent further damage. Some of the vitamins that are good for your knees include:

• Vitamin C: This vitamin helps your body produce collagen, which is a protein that makes up cartilage and other connective tissues. Vitamin C also has anti-inflammatory properties that can reduce pain and swelling in the joint. You can get vitamin C from fruits such as oranges, strawberries, kiwis, and pineapples.
• Vitamin D: This vitamin helps your body absorb calcium, which is a mineral that strengthens your bones and prevents osteoporosis. Vitamin D also supports your immune system and reduces inflammation in the joint. You can get vitamin D from sunlight exposure or from foods such as fatty fish, eggs, cheese, and fortified milk.
• Vitamin E: This vitamin is an antioxidant that protects your cells from free radical damage, which can contribute to cartilage breakdown and osteoarthritis. Vitamin E also improves blood circulation and reduces pain and stiffness in the joint. You can get vitamin E from nuts, seeds, vegetable oils, and green leafy vegetables.
• Vitamin K: This vitamin helps your body produce proteins that regulate bone mineralization and prevent osteoporosis. Vitamin K also prevents calcium from depositing in the soft tissues around the joint, which can cause pain and inflammation. You can get vitamin K from foods such as broccoli, spinach, kale, and cabbage.

Takeaway

Knee popping is a common phenomenon that can have different causes. Sometimes, it is harmless and normal, but other times, it can indicate a problem with your knee joint. If you have pain or other symptoms along with knee popping, you should see a doctor for a proper diagnosis and treatment. You can also take some vitamins to help keep your knees healthy and prevent further damage. Remember to take care of your knees and enjoy your life!