The creaking of leg and knee may be caused by physiological popping, meniscus injury, knee inflammation, etc. 1. 1. Physiological popping: knee creaking during activities may be due to the air inside the knee was squeezed or knee ligaments and femoral condyles and other friction and lead to, usually no discomfort in the knee. 2. Meniscus injury: each side of the knee joint has a half-moon shaped fibrous cartilage that is the meniscus, meniscus injury, rupture will affect the normal movement of the knee joint, ringing joints have a foreign body sensation, etc., can be caused by trauma, long-term squatting labor, etc.. 3. Knee joint inflammation: synovitis, rheumatoid arthritis, degenerative osteoarthritis, etc. can cause knee joints to rattle during movement, and can be accompanied by joint pain, which can be caused by bacteria, intra-articular injuries, degenerative changes in the bone and joint joints, such as the emergence of joints and free bodies. In addition, other diseases may also cause leg and knee creaking, the symptoms please go to the hospital in time for examination and relevant treatment to avoid aggravation of the condition.