The good smart folks at École Polytechnique Fédérale de Lausanne have developed a nice “simple” set of legs to help folks with lower limb difficulties. However, I only say “simple” because there is no crazy complex or invasive interface with nerves, thoughts, or carefully controlled passings of gas (I’ll see if I can get that last one to market). The in put on this unit is a basic manually triggered command for each step using hand controls. As the article and video say, they will improve it eventually to a point where its just a “Walk” command and the legs will manage the steps for you.
When it comes to building Mechs, there are two primary types that come to mind. A robotic suite that you wear, like Iron Man, or more of a vehicle that you drive, like MechWarrior. In the latter case, this technology would directly apply. More specifically, the level they will eventually develop it to, where you say walk (well, not verbally. Through some other input means. Maybe even a simple joystick), and it will walk forward. The machine will handle all the nitty gritty of leg motion and foot placement. A Mech developer could always go the route of wearing some sort of controlling suit within the cockpit (or wherever) within the Mech,and have those movements directly translated to the Mechs own legs, but I wonder how effective that would be. Who knows, we arent quite there yet, but its coming! Get ready!