The pain may be caused by the following reasons: 1. It may be caused by viral infection after the virus has invaded the muscles and joints of the whole body and caused some local aseptic inflammation, usually combined with some symptoms of upper respiratory tract infection, such as nasal congestion, runny nose, cough, coughing, dry throat, sore throat, etc. Some patients may also have fever. 2. This condition is most common in the elderly, and the site of pain is usually in the lower back or even involved in the hip and other places, and the nature of the pain is wandering, usually when not pressed there may be wandering pain, and when pressed or when the pain will increase when the activity.