When we swing our arms as part of a strike there is a method behind the madness.
You don’t anyhow swing your arms because you risk hitting yourself if you swing it wrongly as Paul did when he hit himself in the groin.
We have a way to prevent accidental hits to the groin as explained in Clip 15. That’s why its important to pay attention to the basic processes of each strike so that we don’t hit ourselves especially when the hands are swinging fast.