Poor technique and an existing injury or condition such as arthritis can lead to popping in your knees when you squat. Knee popping may also be described as clicking, snapping or grinding; ice, stretching and proper squat technique can help eliminate it. Severe arthritis and injuries may also require physical therapy or surgery. Consult your physician if the popping is painful or worsens.
Menisci are cartilage in your knee that act as shock absorbers and help make knee movements smooth. Normal wear and tear and twisting motions can cause your menisci to fray and tear. Sometimes pieces of the torn meniscus catch, causing popping noises during movement such as squats. Rest, ice, compression and elevation may reduce inflammation and pain, but arthroscopic surgery is necessary to repair meniscal tears and stop knee popping, the American Academy of Orthopaedic Surgeons advises.
Patellofemoral Pain Syndrome
Patellofemoral pain syndrome is when the cartilage behind the kneecap frays, leading to pain and popping or grinding. Overuse and misalignment of your hips, knees and ankles can cause the condition. Avoid painful activities; apply ice to the area two to three times a day in 20-minute increments; and take anti-inflammatory drugs such as ibuprofen to manage symptoms. To support your knees during activities, wear a neoprene sleeve or an infrapatellar strap, which is worn just below your kneecap. Supportive shoes and orthotics can help with knee alignment and reduce symptoms, too. A physical therapist or chiropractor may further improve joint alignment and leg strength, reducing knee popping.
Over time, the cartilage in your knees breaks down and degenerates. This is called knee arthritis or degenerative joint disease. During weight-bearing activities like squats, the bones of your knee joint rub together and can cause noises such as popping. Although arthritis cannot be cured, treatment can slow down the degeneration and alleviate symptoms. Treatment includes non-weight-bearing exercises such as biking, anti-inflammatory drugs, well-cushioned shoes and orthotics. Glucosamine sulfate pills or hyaluronic acid injections may keep your knees lubricated, reducing symptoms, according to the Knee Foot Ankle website; consult your doctor before taking supplements of any kind, and to discuss the need for any type of injection. Physical therapy or knee replacement surgery may be necessary for persistent or worsening symptoms.
Popping unrelated to an injury may be caused by the movement of gases, ligaments or tendons in and around your knee joints. Gases such as oxygen and nitrogen within your knees can shift during a squat, producing a popping sound. Improper technique, tight muscles and poor alignment of your hips, knees and ankles can increase your risk of this type of popping. Shifting your weight too far forward on your toes, for example, increases the pressure and stress on your knees. This may cause more stretching of your joint capsule, a release in gas and an audible pop, the Library of Congress explains. To prevent further knee popping, warm up with a light walk or jog and stretch before you squat. To squat properly, push your hips back and bend your knees to a 90-degree angle. Keep most of your weight in your heels, your abdominal muscles firm and your back straight.
- American Academy of Orthopaedic Surgeons; Meniscal Tears; February 2009
- Summit Medical Group; Patellofemoral Pain Syndrome; Pierre Rouzier, M.D.; 2009
- Library of Congress: What Causes The Noise When You Crack A Joint?
- Knee Foot Ankle Center: Arthritis Treatment
- “Strength Training Anatomy”; Frederic Delavier; 2006