You are correct 8th. They use their own system. It could be called a rock and pin connection. The upper part of the ankle joint goes up and down. The lower part is on a swivel, and goes side to side. Where the ankle joins to the leg, the lower leg is an inverted U shape, back and front. That only allows the foot a limited range up or down. Up, is similar to what a real foot can reach. Down, the foot is restricted, which makes it unable to reach what a real perons foot can. In other words in can't point. That is possibly one of the improvements the new body will overcome. Let's hope so, because a round house kick using the instep is something common for any martial artist. Unless you want to attempt modifying the joint yourself, by cutting out a bigger area at the back of the ankle, your stuck with how it is.
Yeah, we were all hooked on Bruce's movies big time after FoF. I still remember how pumped we all were for weeks afterwards. Just about everybody I knew had started some kind of martial arts training within months of its release, hoping to become ultimate badass foo fighters, just like Bruce. Heheheh... in their dreams. 
