I taught Kona to crawl using down/stay.
I tell her down, then stay, then move a few feet in front of her, the call her to me. When she would try to walk, I wouls say "No... Crawl" and get her back into the down position. Then I would pull the treat away from her, getting her to crawl on her belly. As you are pulling the treat away from him, and he crawls, be sure to repeat "Crawl", so he learns the voice command.
As for the hand command, instead of moving it in a cicrular motion, try moving it to the floor. I will make you a video showing it.
Kona is having one of her days... and doesn't want to do the trick. I will try again tomorrow, though!!