A couple form checks!

Hi guys, I was wondering if you could take a look at the following form checks for my son.

SL/PE1: https://vid.me/kvZF

This was the last set of mastery with 5 lbs. I know the legs are a bit too straightened out, but his back is still leaning backwards to compensate.

MN/PE2(static holds): https://vid.me/oFow

He essentially held the top of the position for a couple of 12 second sets. Wondering how good it is, and how useful this exercise is.

HBP/PE2: https://vid.me/iNht

He thinks these are all around terrible. Other than the fast pace, what do you guys think he should work on?

MN/PE1: https://vid.me/iNht

Just the last set for mastery. 

Thanks in advance!

I'm wondering why no one is replying, did I break a rule by posting too many form checks at once?

I was wondering what you guys think about my son's performance in the above elements and in SPL/PE2 (last set of 5x45 sec.): https://vid.me/cDOf

I was hoping Zach or some other trainer could comment on the form of my son...

Thanks!

So sorry I linked the pushups twice and did not link the MN/PE1. When I can, I will find the link for tuck ups.

In all the elements your son is moving his head all around which drives me insane...(not really) So here's my 2 cents on Russian Twists:

1. Touch the plate/fingers to the ground and behind your back.

2. Turn the torso and head equally. Which means- don't look at the mirror. You can check your form after recording

Apologies, thanks