Some factors that may decrease pain tolerance are apprehension, fear, anxiety, fatigue, anger, and a perceived lack of personal control over one’s body or fate.
In my own case,I found that having to bend over for the cane, which was an undignified and submissive position, reduced my feelings of personal control,in a way that holding out my hand did not.
Although there were feelings of anxiety, fear, and apprehension associated with both,it was far more pronounced with bending over to get it on my bottom.
I could not see behind me, and therefore I was unable to calculate the expectation of when or where the stroke would be applied, nor be able to gauge its likely force.