I have a hinged leg brace. It often feels as if it is loosening but I just tighten up the Velcro fixings as and when. I loosen the strap near my ankle to sleep as it has felt too tight and I started to get a tingling sensation in my big toe! I don’t think the brace slips too much – it just feels like it. I make sure that mine is as tight as I can tolerate as long as it prevents my knee from twisting. Mine is also set at 45 degrees so I can bend my knee a little. I am NWB for another 3 weeks so I am not actually walking properly with it on – just hopping on my good leg. I don’t find it particularly comfortable especially at the end of the day when the hinges feel like they are digging in .