Quoting Bartosz k
really cool! where do you get those pieces you used as hinges, on the feet of the walker?
If you're talking about the "T" bar, I got them in a large bionicle set a while a go, but if you are talking about the two hinge pieces that are hooked on too the "T" bar, I've gotten them in a bunch of different sets.
If you are trying too find pieces, try bricklink.