>> it will start to feel like tingling in your calf. >> reporter: but this bike doesn't let you forget. these little cords here attach to the muscles in my leg. as my leg is moving, it's predicting which muscle should be using and giving that muscle a stimulation. they call this the superman device. learning to walk without the burden of my body weight. >> 30% of your body weight has been taken out. >> reporter: surprisingly, the shopping cart is also used as part of therapy. take a look here. obviously julie helping if i have right leg weakness, moving my leg along, preventing me from falling. >> i said okay, you say len, it's pen, use your lips. >> reporter: now remember, with congresswoman giffords, speech is also a concern. especially since she has a trache and learning to use it is part of therapy. >> this is what sticks out on the patient. what we have here is a speaking valve. if they're tolerating that,