The first thing to do is to clarify the cause of the muscle pain in the small arm, and then according to the cause of physical therapy or medication under the guidance of the doctor. 1. If it is caused by trauma, intermittent cold compresses within 72h can reduce bleeding and swelling and relieve pain. 72h later, hot compresses are applied to promote blood circulation and facilitate recovery. If it is more serious, it is recommended to consult a doctor in time and use medication under the doctor’s guidance, such as Loxoprofenna. 2. If it is caused by purulent infections, you need to choose sensitive antibiotics under the guidance of the doctor for treatment, such as erythromycin, and if necessary, incision and drainage. 3. If it is caused by over-exertion, you should pay attention to ensure enough rest, can take oral relief of muscle spasm of drugs such as ethylpiperidone hydrochloride, under the guidance of a doctor.