First of all, it is important to clarify what joint popping is. Joint popping is one of the common intra-articular disorders, when the joint is obstructed by some factors in its trajectory, the joint flexion and extension activities will make a sound and vibration, called joint popping. In our daily life, we often find that our fingers make a “popping” sound when they are flexed, and our knee joints also make a “rattling” sound when we go up and down stairs. There are physiological and pathological joint popping, most of the young people’s joint popping belongs to the physiological, while the sound does not cause discomfort in other parts of the body, not harmful to the body, do not need special treatment. In the case of older people, joint popping is often accompanied by soreness, swelling, and other uncomfortable sensations, so it is important to consider pathological popping, which means that the joint may be diseased. The more common clinical lesions are meniscal lesions, patellofemoral arthropathy, free body, cartilage injury, synovitis, etc. Pathological ringing is more common in the knee, ankle, hip and shoulder joints. For example, if meniscal damage is not treated in time, it will aggravate the wear and tear on the cartilage, which is irreversible and can cause serious impact on the patient’s walking. So how to distinguish between physiological and pathological rattling? Generally speaking, physiological popping has the following four characteristics: 1. When the joint is suddenly stretched or flexed. 2, there is a time interval between two joint ringing, that is, the resting period. 3.The sound is crisp and single. 4, not accompanied by pain or discomfort. If the ringing does not meet the above four points, then it is pathological ringing.