abnormal masturbation ?

So this is something that i’ve kept to my self for a long time because i’ve always felt embarrassed but this platform in so open and non judgmental so i’d like to know your thoughts on it.

ever since i was little, i’ve only been able to reach an orgasm buy “humping” a rolled up towel and watching porn. for a woman, i’ve always felt like this was super abnormal.

obviously sex and rubbing my clitoris feels good but it has never led me to reach orgasm.

i think it has something to do with the use of my leg muscles helping me to reach it.

so, am i alone? is there a name for this? let me know your thoughts and opinions please!