With a whiplash injury, many upper back and neck muscles were involved, two most prominently. One, the trapezius refers a very familiar pain pattern up the back of the neck and into the temples. The sternocleidomastoid (SCM for short) was the other. These muscles check-reins excessive forward and backward motion of the head, which often happens in an auto accident, even more so if hit from behind! The common diagnosis is "whiplash injury" or "cervical sprain/strain".
The Upper Trapezius muscle usually has trigger points in it. The common pain pattern is the classic tension headache, up the back of the neck and into the temples. Almost ALL tension headaches are the pain pattern of this muscle. Of course, there are many muscles that were also offended by the unexpected and sudden forward and slam back against the head rest. Each one will be examined and treated if needed.
The SCM can also produce pain, but in addition, this muscle often mimics; the symptoms of a migraine headache including pain on one side of the head, tearing of the eyes, ringing in one ear, runny nose, nausea, dizziness, loss of balance and blurring vision.