I have often heard that some schools offered boys the choice between getting it on the hand or the bum, and boys were by no means agreed about which was worse.
If children were injured by hand-canings, it would have been all over the newspapers, so I guess the teachers new what they were doing.
After a lifelong interest in the cane I have never agreed with caning on the hands – far too dangerous. The bottom is “natures place” and ideally suited for the cane. Having said that I take the point that maybe it was used on girls hands to save some embarassment.
It may well have been a lighter junior cane that was used on the hands