This is a great exercise that builds you delts while also protecting joint integrity. The cable is attached at the bottom of the handle, so you'll be pushing up, not pulling down.
The position of the arm alleviates unnecessary joint pressure to extend shoulder integrity.
The pulley should be set at about the lower chest level.
Elbows are roughly 45 degrees from the body.
Hands are in neutral grip (facing each another).
Begin with 25% of your barbell military press for 4 sets of 10 reps. The video shows Fred Shaka, who normally presses 225 pounds for reps, but trains this exercise at 60 pounds.
Yes, this is super weird. But it nails the transverse abdominis (the deep core muscle that's like a natural weight belt) and even the internal obliques.
You multitaskers out there will love this movement as it allows you to work the rectus abdominis, the obliques, and the serratus at the same time. Too bad the rest of your life isn't as efficient.