The Lateral and Medial Pterygoid, Temporal, and Masseter muscles contribute to the complex task of chewing or mastication; but the Masseter is the most powerful muscle due to its size and position in the joint; it generates most of the force for biting and chewing. Base on my experience, the chewing muscles, and particularly the Masseter, can become hypertonic and painful in clients who clench the jaw, grind their teeth or have other problems with the Temporomandibular Joint (TMJ). There is also a strong correlation between excessive tone in the Masseter and pain in the upper neck. This tension in the TMJ may create or intensify trigger points and tender points. Some symptoms of active trigger points in the area are the headaches or pulling sensation above the eyeballs or on the lateral head area. During the first consultation the therapist must measure the landmark of the hip, looking for dysfunctional posture patterns.