Bone ringing when moving the arm and shoulder may be caused by the following reasons: 1. It is caused by abnormal bone impingement inside the shoulder joint. For example, if the patient has an old shoulder dislocation, which causes instability of the shoulder joint, abnormal bone impingement may occur when moving the shoulder joint, and then produce bone ringing. In addition, if the patient has had a serious shoulder fracture and has small fracture blocks left behind, this may also cause a ringing when moving the shoulder joint due to the impact of the small fracture blocks. 2. It may be caused by tendon lesions inside the shoulder joint, for example, if the tendons inside the shoulder joint are damaged, inflamed or calcified, the tendons may ring when moving the shoulder joint, causing the patient to believe that a bone ringing has occurred. 3. For example, if the shoulder joint has frozen shoulder, the contracture of the shoulder capsule may cause a bony noise when the patient moves the shoulder joint. 4. It may also be caused by muscle spasm in the shoulder, for example, if the patient sits and lowers his head for a long time, the shoulder muscles may spasm, and when moving the shoulder, the spasmodic muscles may pivot over the surface of the bone, producing a peri-bone noise.