Destroyed your knees? How old are you? Do you have some physical limitations that prevent you from crawling on all fours? We don't want you blowing out a hip or anything!
You can always walk to different spots in the room and just crouch down. The goal is not to humiliate you or destroy your knees, it's to get your ears at roughly the same level the subwoofer would be.
You've been coming here with bass issues for the last couple of months now repeatedly asking us the same questions while also dismissing the most basic of advice we can give you. You're going to have to put a little more effort into this or just resign yourself to sub-par bass and be done with it. You're going to have to make some compromises and do a little bit of work if you want to get anywhere.
I told you it is going to take some time and effort to dial it in properly if you really want it to sound good. I can't shake the feeling that you just stuck it where you want it, ran room correction and stopped there...