cartoon prisoner masturbates with his feet

Via Bondage Blog, this detail from a cartoon raises the interesting question — how many men are flexible enough to masturbate with their own feet? I certainly never have been, but I’ve seen photographic evidence that some men are.

(For the time being, I’m content to play the cartoonist’s game, and disregard the added complication and difficulty of doing it with shoulders dislocated, or nearly so, from such a punishing suspension.)