The most common causes of knee pain during deep squatting are meniscus injury, osteoarthritis, knee synovitis and so on. 1. Meniscus injury: if the patient’s meniscus is damaged, the pressure on the knee joint when squatting is too great, it is easy to induce meniscus pain. 2. Osteoarthritis: joint cartilage cells are damaged due to various reasons, and then secondary osteophytes, degenerative changes, squatting in the process of too much pressure may also induce osteoarthritis attacks. 3. Knee synovitis: synovitis is usually associated with acute and chronic injuries to the knee joint, synovial irritation is prone to cause secretion disorders, lubrication of the knee joint is weakened, prone to the formation of joint pain, swelling, effusion, etc., deep squatting may aggravate the symptoms. Caused by squatting knee pain causes more, may also be related to rheumatoid arthritis, ligament damage, fractures and other factors, if the symptoms continue without relief, it is recommended to go to the hospital in a timely manner to find out the cause of the disease, by the doctor targeted treatment.