Originally Posted by Jeddostotle7

The modern style (front-to-back hinge on bottom of shin with horizontal/slightly diagonal pin onto which foot is attached) wasn't introduced until the Return of Marvel Legends, I don't think, but there's been some form of ankle articulation from the beginning; usualy, it was done in more of a "front-to-back hinge on the bottom of the shin with a horizontal bar attached on the bottom that the foot is placed on" during the ToyBiz daty, which of course doesn't give as much range; some figures didn't even have that, instead only having the forward-to-back hinge. During the early Hasbro days, they gave a lot of figures ankle articulation by putting a forward-to-back hinge on top of the foot, and a peg on top to attach into the shin, which gave no ankle pivot.

Sorry if my explanations are insufficient, I have no better way to describe the different types of ankle articulation.