To perform an Axel, the skater typically approaches the jump on a right back outside edge in a strongly held check position before stepping onto a left forward outside edge. Teh skater then vaults over the toe pick of the left skate and "steps up" into the jump with the right leg. Then the skater brings the left leg through to cross in front of the right in what is known as a back spin position.
It is quite common for skaters to skid the forward takeoff edge slightly, especially on double and triple Axels, rather than vaulting directly off a clean edge. The skid helps the blade grip the ice on the takeoff, and is considered acceptable technique as long as the skid is not so great that the skater pre-rotates the jump or takes off the back of the blade rather than off the toe pick. When the skater makes a mistake in the timing of the jump such that the blade does not grip at all and he or she slips completely off the edge, the result is what is called a waxel, often resulting in a fall.
Computerized biomechanical studies of skaters performing double and triple Axels have shown that skaters typically do not achieve quite as much height on the triple Axel as they do on the double. This may seem counterintuitive, since a higher jump ought to give a skater more time to complete the rotation in the air. Instead, on the triple Axel, skaters do not take such a big "step up" so that they can pull in to the rotation position more quickly.
