... My problem with that as most readers here know is I don't believe the head wound is consistent with being struck because it appears to be a low-velocity/high-pressure wound.
BOESP, I agree with you on this. BUT I NEED TO KNOW MORE ABOUT WHY YOU SAY THIS. Because up to now, all I could say to back my opinion is that I thought it was an accident and she was thrown and everyone counters with this is an injury consistent with being hit by a heavy object and nothing else works for this type of injury.
Please tell me why it is possible. Thanks.
Based on the public autopsy report and physics, it is unlikely a striking blow could leave a hole that size in the back of the head and an 8-inch+ split and there be so relatively little damage to the underlying tissue at the impact point. The length that one fracture would/could travel (in this case 8.25 to 8.5 inches, depending on what you read), especially crossing suture lines in a pliable skull, with little damage to the underlying tissue, is limited and likely no where near 8.5 inches.
A swung weapon, relatively, could be low or high velocity depending on several factors. Regardless, her brain matter would be mutilated by the weapon at the contact point more deeply in the brain tissue if enough force was used to create that 8-inch fracture. Bullet wounds, depending on caliber and other factors, are generally high velocity/low pressure (very simply put -- lots of speed but little relative force to the surrounding area). A two-pound hand weight (which might fit that wound) if swung hard enough to make that long fracture would mutilate the brain matter underneath the contact point.
If someone grabbed a child by the collar while pressing their thumb into the child's neck it might do several things. Depending on where the pressure was, even that thumb could subdue the child. If the child was pushed into a doorknob hard enough, that could produce a displaced skull section that didn't break the skin but it would be nearly impossible to create an 8-inch fracture that way. If, however, someone fell on a child after the head struck the doorknob, that would create relatively high pressure to an already existing wound and could force the original, shorter fracture to lengthen. Same thing with pushing a child's head into an immovable object like a heavy bath tub. The pushing motion is low velocity but the possible moments of pressing the heading against the blunt object would create relatively high pressure, especially if force was used. Force is relative -- an adult pressing a small child is relatively more forceful than two adults doing the same action.
She very well could have been thrown, as you said. There are just so many variables about how that head wound could have happened but I can't see high velocity being one of them because of the lack of underlying damage at the point of impact coupled with the length of the fracture. A striking blow would probably lead to a fracture but not one that traveled from the back of the head to just above the brow line in front and certainly not one that left relatively little underlying mutilation to the brain.
Even just using lay common sense to think it through, the "for-example argument" of a three-hundred pound man swinging a bat, on the face of it, is not consistent with JonBenet's wound. Her brain would be mush underneath the contact point. Not to mention, she would have to be in a position to receive a wound that would allow an arm to swing the weapon and hit her on the back, right-hand side. That's a wide arc for those who believe she was struck while in that cluttered basement. Just think about how long your arm is then add in the length of whatever weapon you think was used -- it is highly unlikely that could happen in that basement.
Did that answer work or have I misunderstood? Remember, I'm not a physician, firearm expert, or a physicist. I just have contact with some people who are.