Oh that's interesting, I use a spandex-like component inside the frame but only to hold electromyography (EMG) electrodes against the leg. I reckon you'd still need a support structure to hold the 50-100kg of weight of the user though.

That, or leverage the existing bone. It may even be possible to leverage counter force of the opposing "muscle groups" of nitinol wire using some sort of artificial joint designed to take advantage of it.

In order to mimic muscle wouldn't you need the wires physically attached to your body somehow? Getting leverage with a spandex like material doesn't sound possible.

Yes, the nitinol is not the only component. You would need things to mimic other pieces of the system, like tendons and a way to anchor them to false structures or utilize existing bone.

I mentioned fitting similar to spandex because all these other suits are bulky. Sure, this system would still have bulk, but it should be more conforming than mechanical legs that sit several inches outside of the person's natural legs. Good luck fitting on public transportation, airplanes, or even walking through a 32" door if you were a bigger person to start with.

I imagine that wouldn't be very powerful.

Why?

Reasons others have brought up, and that you have addressed. (Unfortunately I can't delete my comment.)