Maybe I should introduce you to DD2.
She didn't hit her head much, mainly because I was always poised like a coiled spring to catch it and then I taught her how to fall without breaking anything.
Just as well, really, thinking back to the rollerskating down the big slop with a 3 foot drop, the 'I can ride without stabilisers, take them off!', the tree climbing, the 'I'll get on my scooter and hold my dad's dog on the lead and he'll pull me along down the road' (to be fair, yes, yes he did - just not on the scooter after the first ten feet), the climbing frame at school, the footballer knee slides across the quiet section of Sainsbury's - stop, look, listen and think applied to making sure there were no pensioners in the cat food corner in her mind - and many, many more incidences.
I used to get told everytime she gained another bruise at nursery/afterschool club with an 'And we're really sorry, but we saw another bruise as well, so we've had to record that, too' - and then there were the A&E visits where I'd say 'Well, how about you tell the doctor why we're here today?' and the time when she turned but left her kneecap behind...repeated as an adult where she had to be carried up a ladder and two flights of stairs over a firefighter's shoulder because she did it in the bar basement where she worked.
If I'd given her a padded cell, she'd have found some velcro and tried to Bar-Fly herself to the walls.
Nothing to do with sex or gender. Some kids are just wholeheartedly enthusiastic about hurling themselves into things despite the fundamental laws of gravity. You just need quick reactions, a full first aid kit and the realisation that you'll be watching them through your fingers when you aren't actively cringing or waiting for yet another thud.