I was looking at the casa de Kenpo and they stated that they do a chop to the ribs or side then follow up with a left heel palm to the right side of the face...or something like that...i forgot...had a short attention span watching the video...
Anyhow, this is how I explain why i'm doing what i'm doing. I won't get too technical here, only because i'm tired and want to go to sleep
Anyhow, attack is for front two hand push. As I step back with my right foot into a left neutral bow, the two outward chops to the inside of the forearms are used to clear the arms or basically open up your targets. When you move into your left forward bow, yes I use a hard chop to the ribs to stop the attackers forward momentum...my forward bow gives me my bracing angle.
Now here's the ideal response that I want out of him. If i deliver a blow to the left side of his ribs, the attacker will hopefully cringe his side and his body will actually lean to the left to try and ease the pain....well, it's too late because my next strike is a left chop to the left side of his neck while pivoting back into my neutral...now i just utilized opposing forces....Then I follow up with the frictional push/pull down to to abdomen followed by the right vertical middle knuckle strike while pivoting in my left forward bow...then for the upperranks, the ext. to follow(which is an overkill by the way)
So in short, the initial chop to the ribs stopped his forward momentum, created borrowed force for me because of his lean to the left which also increased my power and increased my speed by shortening my distance for the chop to the throat.
...i don't know, that's how i teach it because it makes sense to me