Ok. This is not a simple problem to fix on your own, so it's necessary that you do some googling and educate yourself on your problem. It WILL require a lot of effort on your behalf!
Cause of problem:
* Squeezing ass and stomach for years on years, resulting in dysfunctions.
Main inhibitions:
* Gluteus maximus
* Transversus abdominus
* Psoas major
Symptoms:
*Chronic hamstring tightness
*Chronic hip tightness
*Chronic piriformis tightness
*Poor breathing and stabilization strategy
*Butt 'tucked' under, literally. It's NOT genetic.
*Lumbar flexion
*** HUGE risk of injury to pelvis, low back, herniations, hamstrings, etc
Symptom relief:
* Stretch hamstrings (with a straight back, not the toe touch bull****)
* Stretch piriformis
* Stretch / massage lower abs
*** This is all symptom relief, they will not stop GRIPPING until proper stabilization and function is achieved.
Look at whole, but pay attention to 6:00
[video=youtube;geE7jJmp0Rw]https://www.youtube.com/watch?v=geE7jJmp0Rw[/video]
This may look dull, but you MUST activate your Tr A and cease the rectus abdominus gripping!
[video=youtube;lmZwM0-U5yo]https://www.youtube.com/watch?v=lmZwM0-U5yo[/video]
Reactivation of glute maximus
[video=youtube;tKGR6uceAy8]https://www.youtube.com/watch?v=tKGR6uceAy8[/video]
Learn HIP HINGE: activation of low lumbar erectors (muscles that pull the butt BACK and UP)
[video=youtube;TT838Ha2xmA]https://www.youtube.com/watch?v=TT838Ha2xmA[/video]
If I forgot something, I'll edit the post. My wife is waiting for me to eat dinner
Hope this helps. I've dealt with your problem before, and if you work on these things it WILL fix the problem.
Regards