Why Are My Knees Cracking When I Walk?

When your knees start clicking or cracking during everyday activities like walking, climbing or going down stairs, stretching, or even straightening your knees, it can be a bit unsettling.

While knee clicking is fairly common, there can be a number of reasons for why your knee clicks, especially while running or walking with bad knees.

Most times, the clicking noise in the knee isn’t anything to be concerned about. But what causes the knee to click? Can anything be done to stop the clicking? When would you need to seek medical attention for clicking knees?

Let’s have a look at some of the common causes of clicking knees and what you can do about them!

Why are my knees clicking or cracking?

Clicking knees are fairly common and there are a number of factors that can cause the knees to start cracking or clicking. Sometimes it can be minor and other times it may be more serious. Cracking knees can also come with pain. Or there may be no pain or other sensations when they do crack.

Sometimes the clicking noise is tiny gas bubbles—nitrogen—that have formed and build up in the synovial fluid inside the joints. When you move, these bubbles burst and can cause the clicking noise, similar to when you crack your knuckles.

The knee clicking can also be caused by your kneecap that’s not tracking in the knee joint groove properly. The kneecap can get pulled slightly out of alignment as you move, especially if the soft tissues are tighter on one side of the knee compared to the other side. When you start to walk and move your knee, it will make the clicking noise until it’s back in the joint groove properly.

Both the gas bubbles and the knee not tracking properly happen fairly often—almost every day— to most people.

A muscle imbalance in the hips and thighs could also lead to clicking knees as these muscles are used to stabilize the kneecap.

This sound is also known as crepitus, and while it has been associated with arthritis the noise the knee makes is very different. With arthritis, the sound the knee would make would be more of a grinding or cracking sound.

Other Possible Causes

There are a number of causes that can cause clicking knees, especially if it’s accompanied by swelling, pain or discomfort.

If one has had a serious knee injury which hasn’t healed properly, this can develop an excess of unnecessary tissue—scar tissue—around the knee. When you move or extend the knee, this tissue can cause the clicking sounds.

Another common cause for knee clicking is known as Patellofemoral Pain Syndrome—also known as Runner’s Knee. This is when the cartilage of the kneecap rubs against the femoral trochlea, which leads to inflammation and irritation.

Sometimes this has to do with the structure of your knee, as your kneecap may sit higher above the knee joint. But it can also be caused by a muscle imbalance in the hips and thighs, or even tight Achilles tendon or tight hamstrings.

The meniscus is a thick, rubbery cartilage that acts as the shock absorber to the knee joint—between the femur and tibia. If you had to suddenly twist the knee while bearing weight on it, then this can cause it to tear.

You may hear a popping sound as it tears, followed by pain, swelling and stiffness. While you may have difficulty straightening your leg, you may also hear the knee click when you do try and move it. If you do have trouble moving your knee, then it would be best to have your doctor have a look at it. If the tear is severe, then surgery may be necessary.

As we get older, the cartilage in the body changes and becomes thinner and the synovial fluid—which lubricates the joints—becomes less. When this happens, the cartilage becomes rough—or wears down completely—and then the knee joint moves with more difficulty as the bones rub against each other. This is known as osteoarthritis. Along with the clicking, you may hear your knees making a grinding sound or even a creaking sound when you move.

As we move during our daily activities, we move the knee the joint and this changes the position of the tendons and ligaments. These soft tissues keep the knee joint together and when you move, you may find that when they move back into position and there’s a snapping, popping or cracking sound. While this sound may be unsettling, there’s usually no need for medical attention, unless it’s followed by pain and swelling.


If you’re experiencing discomfort, pain or swelling in the knee, the best thing to do is to rest your knee and follow the RICE principle.

RICE stands for:

  • Rest
  • Ice
  • Compression
  • Elevation

This will help to alleviate pain, reduce swelling and promote healing. To allow your knee time to heal, take a break from daily activities and your training routine. To help alleviate the pain and reduce inflammation, you can take an anti-inflammatory medication like ibuprofen—Advil or Motrin IB.

You can also use a compression sleeve, as this will increase the oxygen and blood flow to the knee as it will insulate your body heat. Ice your knee four to six times a day, for no longer than 20 minutes at a time, and make sure that the ice pack is wrapped in a towel and not put on your skin directly. This will also help to reduce the pain, swelling and stiffness and promote healing.

If you have to move or be active with bad knees—no training or sporting activities—then wear a knee brace, as this will provide stability and support to your knee while reducing the risk of further injury.

If you are able to walk, make sure you are wearing correct footwear for bad knees.

With that being said, for more severe knee injuries your doctor may recommend either surgery or physical therapy to rehabilitate and heal the knee.

When should I see a doctor?

You should see a doctor if the knee pain is severe, swelling or if your range of movement is restricted. If you don’t have any pain or swelling, then rest the knee and monitor for a day or two to see if there’s an improvement.

With that being said, if you’re concerned about your knee and you’re doubtful then see the doctor and discuss your concerns.

Healthwise Staff. “Rest, Ice, Compression, and Elevation (RICE)” Current as of November 2020. https://www.uofmhealth.org/health-library/tw4354spec

LaPrade, Robert. “Trochlear Dysplasia” Accessed July 2021. https://drrobertlaprademd.com/trochlear-dysplasia/#post-86