Punching from the hips

During every class we do Hitch-step and Tai-sabaki drills from a straight punch. For a long time I heard "don't flare your arms" "stay low" "don't square off" and "don't shrug your shoulders" as I would Uke. I still need those reminders today, though I have noticed a sharp decline.

A few days ago, I asked a friend of mine to show me the kinds of things that she had learned in her MMA dojo. Through watching her and seeing the opportunities I could have during sparring, I was able to identify my own mistakes.

Squaring off: A person who refuses to turn their hips as they punch would have a very limited reach. So in an effort to extend their reach, they become square.

Flaring arms: There is only one way to straighten an arm and that is through the elbow. If the body is static and square the elbow has to flare.

Shrugging shoulders: This happens when you want to punch improperly but to do so with some speed.

Popping up: I don't think that this serves a specific purpose, but if your legs are straight and your upper body is stiff (as you're punching) then this is a likely effect. Punching from the hip eliminates this as your legs are bent and your body's energy is able to find a better direction to travel.

Where I once believed that these were individual and unrelated mistakes; I now realize that each of these mistakes is a compensation for a single greater error of not moving my hips.