Possible causes of arm pain and sometimes back pain include prolonged braking, overwork, rheumatoid arthritis, etc. 1. Prolonged braking: it may be caused by prolonged braking. If the patient has been working for a long time, the muscle spasm in the waist and arm is caused by the long time inactivity, and the symptoms of weakness and pain in the above mentioned parts will appear. 2. Excessive fatigue: It may be caused by excessive fatigue, such as the patient’s heavy physical labor such as bending over to carry heavy objects or excessive strenuous exercise, etc., which may cause muscle fatigue in the arm and waist, or a large amount of lactic acid accumulation and thus cause pain. 3. Rheumatoid arthritis: It may be caused by rheumatoid arthritis. Rheumatoid arthritis typically manifests itself in the form of wandering, multiple large arthritis. Elbows, knees and shoulders are mainly involved and painful symptoms appear. In the case of relatively large changes in the weather, it can also sometimes cause back pain. Arm pain and sometimes back pain may also have other reasons, such as herniated disc compression of the nerve, rheumatoid arthritis and other diseases, such as rest pain can not be relieved, it is recommended to go to the regular hospital in a timely manner to improve the relevant examination, to clarify the cause of the disease, under the guidance of the doctor for targeted treatment or therapy.