Pain when arching the back at the shoulder blade seam may be caused by bad posture, and may also be caused by dorsal fasciitis, neurogenic cervical spondylosis, and muscle injury at the shoulder blade. 1. Poor posture: maintaining an incorrect posture for a long time or sitting for a long time will cause the back muscles to show a tense state, and a sudden arching of the back will cause the back muscles to be pulled and damaged, resulting in pain at the scapular suture. 2. Dorsal fasciitis: due to cold stimulation or excessive exercise, it will lead to aseptic inflammation of the dorsal fascia, which will increase the stimulation of the dorsal fascia when arching the back and cause strong pain and discomfort. 3. Neurogenic cervical spondylosis: After the degenerative changes of cervical spondylosis, the nerve roots around the compression, so that the innervated parts of the numbness, pain, and activities will increase the stimulation of the nerves and intense pain, so that the scapular suture has a strong sense of pain. 4. Muscle injury at the scapula: the scapula is the starting and ending point of the rhomboid muscle and other muscles, when these muscles are injured, it will cause pain in the scapular suture, and if back arching is carried out, it will stimulate the local injury and enhance the back pain. There are many reasons that cause obvious pain and discomfort in the scapular suture when arching the back, if it is difficult to relieve, it is recommended to go to the orthopedic department of the hospital in time to get a clear diagnosis and get professional treatment as soon as possible.