Yesterday, I saw a client who said he has no medical issues nor incidents in his medical history of which I needed to be aware.
When I tried to take him over My knee for a firm spanking he told Me that he had a herniated disc at the base of his back.
I do not ask questions about medical history for fun, to pry into your life or as a matter of formality: I want to take complete control and I can only do that if I have the same information about you and your body as you have.
As an example here is a good article specifically relating to electrical play which, My existing clients will know, is one of My top favourite activities: https://www.kinkly.com/2/12904/sex-tips/bdsm/9-things-to-check-before-playing-with-electrosex
Kindly take your safety as seriously as I do.