this might help with the rack pulls explanation (taken from superior muscle, dogcrapp's home):
"Rack chins: Find the widest smythe machine you can (or barbell in a
squat rack) and put a bench in front of it- put the bar about shoulder height- use wrist straps and put your grip as wide as comfortably possible-put your heels up on the bench but cross your legs to take them out of the movement- your legs should almost be straight but not quite- now do chins explosively up and 8 seconds down until the full stretch- any rep that your chin doesn?t either go over the bar or hit the bar doesn?t count! Do one warm-up set and then have someone put a fixed plate barbell (like used for barbell curls) in your lap. On every rest pause the spotter grabs the barbell off the chinners lap and the chinner stands up and counts his 15 deep breaths (and he stays strapped up to the bar). Then the chinner gets back into position after 15 deep breaths and the spotter puts the barbell back on the chinners lap. I want one warm-up straight set with no added weight done for 10-12 reps and then one all out rest pause set for 15 to 20 reps with added weight (use a 30lb barbell this first time out), then 10-30 short range static reps at the end. These are going to be excruciating and tomorrow your lats are going to be killing you. This exercise is my lat width pronto exercise.
You can rig this up where you don?t need a spotter. I?ve done this before by putting my weight belt really loose around me and putting a 35lb plate down the back of it with a short chain, or you can rig up some benches where you can get that barbell off your lap but it?s much easier if you can get someone to help you for the one working rest pause set. You need to really push the stretch down the bottom and then try to explode up to the bar on every rep."
greetz
