Ted Lewis, also currently credited as Ed Paul, is one of NY's most well-known voice actors.
circular movement around an axis: dorsiflexion: decreasing the angle of the ankle joint so that the foot bends backwards (upward) plantar flexion: the motion that extends the foot downward toward the ground as when pointing the toes: plant/o: sole of the foot: supinaton: as applied to the hand, the act of turning the palm forward, or up: pronation
You can think of a step as the tilting of a lever. The ankle is the fulcrum, and one of the arms of the lever extends back to the point above the heel where the Achilles tendon attaches. When the foot hits the ground, it decelerates, and in order to accelerate the foot again, the calf muscle contracts. It pulls up on the Achilles tendon, thus tilting down the other arm of the lever, which extends to the point on the sole where the force is applied to the ground.