If it was hands for girls, the fact they have more fatty tissue down there might also explain a thing or two, sexual connotations apart, though that aspect might just have spared the ladies, unless faced by Ketta’s monster!
The other thing-did they ever spare the WRITING hand?
I think that they used a lighter cane on palms than they did on bottoms, so it might not have been as vicious as it sounds.
Even if they weren’t aware that bottom caning was “sexy”, I think that some teachers thought that it was undignified for an older boy — by caning the hand, they hurt him but let him keep some self-respect.
I think that most teachers held onto the victims wrist while whacking his hand so “pulling the hand away” might not have been a problem. (I’ve also heard that victims were sometimes specifically told to close their eyes.)