Im not able to bend my leg as normal. The transmitter box is a simple unit that does require power from a USB source but rather than plug it in to my TV I use a normal 3 pin USB charger plug that most phones use nowadays so I plug direct in to an extension for all my power, obvioulsy you can plug the USB directly in to the TV but if you dont have enough or any at all the 3 pin option is a superb saver if ports are limited. Sound quality isn’t mind blowing, but it’s perfect for working out and calls. Really disappointed with this as they are not cheap slippers. They were very soft though and looked good. I dont know if I want to try to return these and get another set, or just return them for credit. I’ve been using it for the past month and love how comfortable the material is against my skin. I havent have a single blister since! I needed some to just put on in the morning or hang out after work. Id recommend buying those instead