It’s certainly true that there were teachers who abused the use of corporal punishment – but in my experience, there were far, far more cases where it wasn’t abused.
Children are still being abused in schools today. If eliminating any possibility of abuse is a justification for the elimination of practices that can also help children, then logically we should be outlawing a great many things in schools – if not schools altogether. We’d certainly have to abolish PE lessons, school camps… well, quite a lot of things.
I also agree that it wouldn’t have been that uncommon in the 1960s for a boy who was caught running on the stairs to be physically punished. It’s a dangerous activity and it needs to be discouraged. Even today a boy will be very ill-advised to let me see him doing it at school.