Squatting for a long time knee pain dare not straighten may be muscle spasm and other physiological reasons, may also be trauma, chondromalacia patella, knee arthritis and other pathological reasons. 1. Physiological reasons: part of the population after squatting for a long time, resulting in local muscle tension, spasm, ischemia and so on, leading to patients with temporary knee pain do not dare to straighten, is a normal physiological phenomenon, the majority of patients can be relieved after rest. 2. Trauma: due to collision, fall, excessive exercise and other traumatic injuries resulting in meniscus injury or ligament injury, patients can appear knee pain do not dare to straighten. 3. Chondromalacia patella: due to long-term squatting, friction and other factors can cause inflammation of the patella, patients may experience knee pain and dare not straighten the symptoms. 4. Knee arthritis: rheumatism, rheumatoid and osteoarthritis and other diseases, squatting for a long time can cause the pressure of the joint cavity increases, extrusion of the surrounding tissues, which can cause the patient’s knee pain do not dare to straighten. Squatting knee pain for a long time do not dare to straighten may also have other reasons, it is recommended that patients go to the hospital to improve the examination of the knee joints, clear the cause of the disease to give targeted treatment.