Wish I could help but I have a walker (with 4 wheels) not the kind you kneel on. I mean...I kneel on the seat of mine often when I am standing and sometimes if I need to just scoot a very short distance...but it's not made for that. I know in doing the research for mine it was critical to get the larger wheels and they are better on uneven surfaces. It also helped a lot to read reviews on websites (amazon.com had a lot that were good for me). You'll read about lots of things you might never have thought of yourself and people are usually brutally honest about the pros and cons in those reviews.