I was often hit by both parents when growing up and both would let fly with slaps to the head/face or occasionally aim for the bottom or legs. More often than not their slaps ended up striking anywhere – particularly when you could see the blow coming and tried to swing away from it.
Some slaps to the head or ears did cause harm and would leave the ears ringing and sometimes leave us (I had 2 brothers) dizzy for a minute or two. It was surprising that we didn’t come to more harm with slaps around the area of the ears and eyes.