Back pain with arm pain is usually caused by myofasciitis. Myofasciitis is often caused by cold and strain, and the first symptom is pain in the back and inner scapula, which can radiate to the ipsilateral shoulder and upper limb, resulting in soreness and weakness of the upper limb, especially when straining or sleeping at night when the upper limb pain is more obvious and significant, and there can also be shoulder pain and discomfort. In this case, early examination of the shoulder and back as well as X-ray and CT examinations should be performed to exclude other diseases for diagnosis. Local physical therapy, such as acupuncture and massage, should be performed early so as to relieve the pain, but the course of myofasciitis is relatively long, and only persistent treatment can bring relief and cure to the condition.