A common neck and /or head tie takes place on the back of the neck. Many Thai boxing style clinches are also demonstrated with the hands up and around the crown of the head. However, there remains a biomechanically more efficient place to pull the head downwards in order to break posture.
Why do people opt for head control over gripping at the neck of lower down, such as on the collar or underhooks?
Thaiboxers have long clinched at the crown to break posture at the end of the last lever of the human body. As Archimedes remarked “give me a lever long enough and I will move the world”. The last lever of the body offers tremendous leverage. With the posture broken, strikes can be thrown, especially knees. However, the biggest determinant of where to grip should be the height of your own shoulder. Nobody will realistically attempt to thai-clinch someone who is significantly taller. Furthermore, the optimal placement for a single thai arm on the head is actually on the opposite side of their head as demonstrated above. The reason for this is the strength curve of the neck. Necks are pretty strong forward and back. They are not weak laterally. But pull the head down at an angle midway between forward and lateral, and the neck is surprisingly weak. The arm pulling retracts, thumb retracting outwards ideally to full contraction as if posing the bicep. Clearly some connection is needed on the opposite side in practice, usually with a wrist or sleeve grip. The elbow on the head grip should remain blocking and fully connected to the opponent’s shoulder.