I was wondering if doing long headstands can actually flatten your skull. Unassisted up against the wall. Can your skull uphold to the pressure of your bodys weight on it?
Thanks
You can’t flatten your skull while doing a headstand. I’ve heard of people who hold headstand for over 30 minutes. It all depends on how you feel and what your body is telling you. You can definitely feel the pressure on your skull/head when performing a headstand, but you can use your hands to support you.
I hope this has helped you.
Ugh!
You can’t flatten your skull, but you can your discs. You should not be supporting all of your weight through your neck and head. Some will disagree. Your discs & vertebrae will not.
siva
It is a the cloudy view indeed that promotes a belief sirsasana is “bearing the body’s weight on the head”. The foundation of the pose runs from the outer pinky to the elbow. This foundation supports the majority of the body’s weight, as it should.
To do otherwise, for most people, places them at great risk for cervical spine injuries (neck) as Siva mentions above.
I second his “ugh” and raise it one “gad”.
When you were a newly born and the skull was still soft and hadn’t fused together, yes then a headstand might “flatten” your skull. Question would be if you can do a headstand at that age? 
By 10 months your skull start to harden and by 14-18 months your skull is completely hardened and knitted together, the fontanelle has closed etc. and it would be difficult to change the shape after this except throught a bad accident.
About the rest of your question, you have already received good info from Siva and IA.
Oh nope it’s impossible to flatten your skull. I do breakdance, with headstands and headspins very frequently, and it’s all okay and fine. Just that when doing heastands, remember to lock your neck, and do stretching before doing it, to prevent sprains. good luck trying!
If you do bregma( least to begin with) it’s easier to allow your neck and head to hang ,or [B]rest [/B],rather,[B] in full supension[/B], so all your weight ( practically) is on the arms albows and shoulders,exactly where ti should be. Unless as Siva says you were some of the most advanced asana yogi, dharma mittra, or plainly reckless ressting any weight on your head is not what the skull is designed for, or your discs for that matter. the discs will absorb,eeech, the pressure. you want to be kind and gentle on yourself.this is gd yoga, surely.
The human body is extraordinarily heavy,the weight is immense, if you’ve ever tried to drag someone unconscious or otherwise you will know this. usually takes two or three strong men.You would never guess this unless you’ve encountered a limp body.
bregma is also easier and less tippy,easier to balance. then you could try crown at some point. but like anything in yoga rushing is a recipe for trouble. you have your whole life to ‘launch’, move in a controlled fashio more like, into headstand.
practice your down dog alot to build up arm strength,maybe even dolphin, do some standing poses to strengthen your legs and stablisie your core somehwat for a few months then you could try