Yes, to the idea of doing them standing.
But, I'd cobble together a simple foot stirrup with a cable connection located right around the heel. Then, hook it up to a cable that itself is hooked to a rope and toss it over the top of a chinning bar. Pull the slack out and your heel up to your butt, then hold it there with your hand or hands . . . and start thrusting your foot down to the ground for reps.
Repeat and rinse, as they say!