First: I'm a carpet rookie. We have a remote cabin where it is hard to get tradespeople to do work, so i decided to install one room of carpet myself. I wanted to give myself every advantage so i bought this kick tool and the carpet knife also. Really worked well! There is no way around the fact that it's tough on the knee! My "one room" really had an attached closed with a double door, so was basically two rooms attached... which i did with one long piece of carpet... turns out it should have counted as 3 simple rooms. My knee took a couple days to be fully recovered. if your knees are not used to doing this every day, you may plan on doing one simple room each day or two (or just tough it out! Fair warning... :-) ) This tool is great, awesome padding and the teeth never slipped on the carpet. I was happy with my decision to get a quality tool!