In his 1984 catalog, ski visionary Paul Ramer introduced the MotiveAider System featuring an "Extra strong UNIVERSAL binding and toe adapter with an articulated molded plastic cuff" that extended most of the way up the calf and claimed to allow skiing in any kind of boot, even an after-ski boot, eliminating the boot completely from the "functional system." There was even a shock absorber between the cuff and the binding.  Price: $350. I don't know if many of these spacey-looking units ever sold. I was once descending from Rogers Pass lake near East Portal and overtook Ramer himself on one of these units. I don't think it was much help on this at times narrow and steep trail. I was on little wood XC skis and those squishy boots lined with fake fur. It was easy to jump back up and keep going after falls, which were many.