Pain in the neck, back, eye, head, and shoulder muscles can be a symptom of inflamed chewing muscles and TMJ. Our bodies are remarkable in that they will compensate for weakness to operate even when injured. If we fatigue our jaw muscles, other muscles compensate, and they too can become fatigued. Thus, you can start getting muscle pain that seemingly has little to do with TMJ and chewing. These other muscles include pain in your neck, upper back, shoulders, back of your eyes, and back of your head. For each person, it is different which muscles will become fatigued. Most commonly, neck pain is associated with TMJ.
Jaw muscle fatigue can happen in reverse too. For example, if you overuse your neck muscles and they become exhausted, your jaw muscles can start to compensate. The jaw muscle then becomes tired and sore. Either way, the result is a lot of head and neck muscles become worn out, tired, sore, and inflamed.