Me and mine don't even close it on impact, and we've never had a problem. It's a structure thing. Now, I'm arthritic to start with, so I'd much rather grab and elbow if it's not a gloves-on kind of thing, but still... no problem. I think I mentioned earlier talking about hooks, we have a guy once a year or so come down to play who'll hold live moths or crickets in his fist while whaling on pads, a pushboard, or, hell, the wall, and then let them go, just to prove the point.
My choice is to keep a loose fist when I'm doing CM, I find it works better for me than an open hand on the head. I tried it on the heavy bag btw. All I had to do was to shift the thumb into position, and clench tight before impact.
Surprisingly, I found that I didn't have to consciously think about closing my fists even when I tried the open hand on head method. I could throw a few quick shots and somehow unconsciously my brain will tell my hands to clench just before I hit. But it was harder than keeping a loose fist on the head.
Does anyone else have problems with tired biceps when doing CM with gloves on? :D
I took a look at the videos and there are some solid techniques in the clips. I am happily suprised. Some people will ike what he showed and others will not. But any one who studied the sweet science knows that "styles makes fghts".
The Pek a boo guard he was using is also common in Jailhouse rock as well. Anyone from New York esecially Do or die or the Boogie down has seen and possibly used it before. He should be a bit crouched over though, to avoid atacks to the body. A semi crouch or better. Something akin to Iron Mikes posture in his "glory days".