Hello, first post here. You're missing a hypochondria section, so this one will have to do it, I apologize. I apologize also for this question may seem to better belong to Yahoo answers than here.

As in the headline, how much external pressure is required to deform the skull of an adult man?
This kind of information should be widely known - I guess all kinds of tests on helmets and safety equipment need to quantify the interested forces - but I couldn't come across it after extensive searches.

I am wondering about the steady pressure such as the one coming from compressing the skull with one's hands.

Thank you for any insight.

Welcome to NeuroTalk.

I doubt there is a single answer to your question. I don't think hand pressure could deform a person's skull without some extreme effort and leverage. Some skulls had thicker/stronger bones than others. Soccer players have been observed to have thicker skulls due to the repeated trauma of heading the ball. Bone strengthens when it is repeatedly put under stress.

Before the sutures between the plates fixate, some movement of the skull plates would be more possible. Sutures fixate in most people during the middle to late teen years with the extreme happening in the early 20's.

Cranial Sacral Therapists claim otherwise but research indicates they are wrong.

The forces measured in the helmet industry usually pertain to G forces related to concussions as in football helmets and other high speed forces related to fractures as in motor cycle helmets.

What is your objective with this question ?

Don't laugh. I had a medical check-up and I didn't like the way the physiatrist handled my head, pressing and rubbing on both sides at the same and asking if I felt the same on both ones.

I have had some unusual headache since then. I am subject to migraine. Thus, if I get a different kind of headache, I get concerned.

I don't think anyone is laughing.... your question is important, so I looked up some things you might want to read:

example:
http://integrativeworks.com/understa...-of-your-head/

There are many nerves, and blood vessels in the scalp and some of these nerves come up from your spine and radiate out around the outside of the skull/ head. If inflamed, these areas hurt and cause pain nearby.

So perhaps your therapist was looking for tender points in the scalp areas to see if any were acting up.

An adult human has a very hard skull, and deformation is not really common. Things in the skull crack or break, instead of deforming. If you had a bone disease where the bones soften and do not maintain their strength, then some deformation may be possible, but it is not likely. Bone scans can reveal these uncommon diseases. Just as uncommon is extra bone in the skull. Sometimes Paget's disease causes thicker bone there.

Many headaches originate in the neck and back of the head. If yours persists you should contact your doctor.

Adding context to your question really helps. I can understand how the manipulating of your head can cause problems. I just don't think it caused any deformation. As MrsD said, there are a plethora of nerves and blood vessels that can respond to finger pressure. There are also muscles attached to the skull that move the jaw and neck. These can spasm when traumatized.

Was the physiatrist an MD or maybe an OD (osteopath)?

Thank you for the answers so far.

It was a MD, allegedly a good one, as I looked for a good specialist after getting a first opinion I wasn't particularly happy with.

What symptoms are you seeking help with ?

Have you suffered a concussion or mTBI ?

No, nothing of that kind, as far as I know. I was visited because of a suspect scoliosis.
Also, I have some sort of paresthesia on the left side of my head (left top), which is my migraine side, so I was investigating if it may be related with any cervical issue, but apparently was not. That's possibly the reason for the MD was a bit intrusive with touching my head.

I shall just use this old thread, so that I won't fill the board with my hypochondriacal rants.

Yesterday I was at the dentist for the removal of a partially impacted wisdom tooth.
However, during the removal, the dentist was wielding the drill with his right hand, while laying his left forearm and wrist on the top-left of my forehead for balancing himself. I could actually notice the pressure of his arm on my head especially because he had a wristwatch that started to bother me at some point.

Well, then: consider that the back of my head was laying on the not so soft dentist chair. Consider that the dentist was pressing his left forearm against my forehead in order to have a good balance and steady right hand while drilling my tooth. Do you think he may have exercised enough pressure for my skull to temporarily deformate?

Yesterday I had mild headache and drowsiness (still feeling a little funny). Of course there were other risk factors: local anaesthesia, stress, no caffeine nor breakfast in the morning; the left side of my face was numb for half of the day, due to anaesthesia. In any case, I worry. I have no idea about the non-impact forces that may cause an adult, healthy skull to deformate. I have been looking for that kind of information but I cannot seem to find any useful bit. Any insight shall be appreciated.

I'm no doctor but I boxed for two years and got tackled headfirst onto a rock while playing football many years ago. Never got a skull deformity. I can almost guarantee that the dentist didn't deform your head.