If there is an inexplicable soreness of the right arm muscles, the first thing to consider is the inflammation of the tendon sheath of the arm due to recent fatigue, which is a sterile inflammation. You need to do some local heat and physiotherapy to relieve the pain and discomfort. For obvious pain can choose some non-steroidal anti-inflammatory drugs for pain treatment, such as oral diclofenac. It is also necessary to exclude the possibility of cervical spine pathology, if there is a long time low head bad habits, it is easy to compress the nerve, radiating to the arm, causing symptoms of soreness and pain. In this case, you need to do a CT examination of the neck to clarify, if there is a problem of cervical spondylosis, you can do physical therapy and traction for the cervical spine; in serious cases, you can also perform minimally invasive surgery for the cervical spine, and usually pay attention to good posture habits.