Increasing PPT?

So I have been thinking about something, when you are PPT:ing to your maximum and going for a hollow body, can you train for more ROM in the PPT?

The reason I ask is because I have noticed that when doing straight-body work (planks and pushups) I always try to PPT as much as possible yet I still get a slight arch in my lower back. This even happens when I stand fullly erect and PPTing like mad and tensing my glutes and abs as much as I can, and I still can't get a nice straight line from shoulders to hips. There is always a little arch in my lower back.

Now, is this something one can improve or is this just the way my body is? Could it be that I have more mass on my glutes and upper/mid back compared to my lower back? When looking at the guys in the F1 videos they have a much straighter line going on than what I do. Perhaps I am too tense somewhre and this can be fixed by stretching/foam rolling?

Would love an answer to this cuz I keep reviewing my F1 form videos and I am never fully sure if I have correct form or not. 

Sorry for the long post but this is really bugging me.

To access more range of motion in the PPT, I have found stretching the hip flexors and internal rotators to help. I used kit laughlin's material, mostly. Also I've tried to sit around less (it may be the case that you have accentuated APT). And finallly, I did Ido Portal's diagonal stretch. These 3 on top of Foundation have helped me to solve my PPT issues. I think you might like that lunge solo hip flexor stretch (I forget the exact name) on Kit's Youtube channel. That exercise has always instantly delivered me quite a bit more range of motion.

Biren P. said:

To access more range of motion in the PPT, I have found stretching the hip flexors and internal rotators to help. I used kit laughlin's material, mostly. Also I've tried to sit around less (it may be the case that you have accentuated APT). And finallly, I did Ido Portal's diagonal stretch. These 3 on top of Foundation have helped me to solve my PPT issues. I think you might like that lunge solo hip flexor stretch (I forget the exact name) on Kit's Youtube channel. That exercise has always instantly delivered me quite a bit more range of motion.

Nice! This is exactly what I was looking for 

No problem, though I am also interested if anyone else has a different answer, as I am only answering from experience. And from experience, fixing APT and PPT is a journey measured in many months, not weeks. Something for you to keep in mind, as I have been far too frustrated in the patience needed for these things

Biren P. said:

 ...fixing APT and PPT is a journey measured in many months, not weeks....

Ain't that the truth...truth be told, once you get passed the uncomfortable first couple days/week and get the soft tissue work out of the way, it's not so bad. some of the mobility in F1 got that much easier, albeit the volume in the PE's took a hit because of how weak I feel using a new body shape. xD

Biren P. said:

No problem, though I am also interested if anyone else has a different answer, as I am only answering from experience. And from experience, fixing APT and PPT is a journey measured in many months, not weeks. Something for you to keep in mind, as I have been far too frustrated in the patience needed for these things

Yeah it's not like I am in any kind of hurry, I'll see if I notice any change