There are two main reasons why the bones of the shoulder may ring when the shoulder is rotated. 1. Due to the degeneration of the shoulder joint, the articular cartilage gradually wears out and becomes uneven, and there is local calcification and osteophytes, resulting in a narrowing of the joint space of the shoulder joint. The soft tissues in the shoulder, such as muscles, tendons, ligaments, fascia, etc., are fatigued and cooled for a long time, resulting in a decrease in the elasticity of the local soft tissues, and these soft tissues produce a large plucking force around the shoulder joint where the bones are attached, resulting in a sound similar to a bone ringing, which is actually a plucking sound between the bones and soft tissues.