Most traditional Tai Chi Chuan forms start with ” grasp the birds tail “. There is often a transition where it appears as if we are holding a ball. The form can be trained energetically where we are sensing the energy between our palms and even forming an energy ball. The posture actually is an excellent posture for protecting upper and lower at the same time. It is very similar to the “Philly Shell” from Western Boxing. The big difference is that in the forming of the shell we will file our opponents arm with our arm. This action serves to turn the bones. The filing and protection are done with the outside of the arms as there are less arteries and tendons and more muscle on the outside of the arm. If I am going to get cut, it is preferable to be cut on the outside of the arm versus the inside of the arm where a tendon or artery could be severed thus changing the outcome of the fight quickly. The filing is produced by the turning of my waist, which in turn , turns the arms. We ” coil in to coil out ” and in the process put a lock on the arm. This action takes away your opponents ability to effectively kick or strike with their free hand.