If the symptoms of muscle stiffness in the back of the neck appear, there may be the following reasons: 1, often low head, whether work or study will cause damage to the muscles and ligaments around the cervical spine, the more frequently and longer the head is lowered, the greater the chance of injury and the more severe the degree of injury. This is because repeated injuries can cause scars inside the muscles and ligaments, resulting in poor local blood circulation and local stiffness. 2. Patients suffering from cervical spondylosis, because of cervical spine osteophytes stimulate the surrounding soft tissues so that the soft tissues produce inflammation-like reactions, inflammation repeatedly will make the surrounding soft tissues change in nature, and the symptoms of local stiffness will appear. 3, If the living environment is cold and humid, the back of the neck will feel external stimulation for a long time, and the pain and discomfort of the back of the neck will appear, and if it lasts for a long time, the stiffness of the back of the neck will also appear.