Maybe my searching skills are letting me down, but I can't find any threads specifically about this movement.
My question is, what is the correct ROM for the movement? I understand this is a slightly silly question considering we have a reference video, but the angle it is shot from and the athletes shorts make it difficult (for me, at least 
) to see how acute an angle is supposed formed between lower and upper leg. The first rep in the video appears to have less ROM than the following four (about 45 degrees ish?), so I'm guessing that should be discounted. Should glutes touch ankles? That seems like a tough ask to pull out of...
Background-wise, the SLS series is one I'm making fairly steady progress on (not too surprising as I've luckily always always been able to do SLS's, even without specific training- about 10 per side before starting F1). The PE4 iM is a different ballgame though; this is a movement I was super-weak in when I first attempted it. It certainly isn't a mobility element for me, being far more strength demanding that the PE!
Rather than work a small range of motion, my method for tackling this has been to perform these assisted with a larger ROM than I would be capable of alone. I hold a rope tied to a door handle and let my arms take a proportion of the weight when the movement gets to the point where I won't be able to pull back up with good form (below 45 degrees or so), and then provide just enough assistance to successfully pull out of the bottom position (sort of like the opposite of an assisted natural leg curl) without creasing at the hips.
I'm definitely getting stronger through the ROM and have now ditched the crutch to try to improve further without becoming psychologically dependent. I'm just now not sure how far I have to go 
.
As an aside, (and a point I must keep reminding myself about through the course of Foundation), progressing through the entire 12 week cycle even though I could already complete 5x5 of the PE fairly comfortably has continued to improve my SLS strength, stability and leg power a fair bit. Everything just feels more "solid" (I guess this is similar to the grease-the-groove concept). Not bad considering the reduced ROM of this movement compared to a full SLS. Working at the limit certainly isn't necessary when trying to progress. This also begs the question, would it often be beneficial to complete a 4-12 week cycle of a specific element anyway even if you are able to show mastery at first attempt? I'm almost reluctant to move on in case there is more that can be milked from this PE!
Thanks
Andy
