Here you see Hirscher outside leg already straight, with strong edge angles at the skis. He has a bowlegged set up with his boots. The Bowlegged set up is the most successful in Slalom with shaped skis.
Knock Kneed Alignment
Here you see Ted Ligety, this is a weak position, his ski, edge angles that let the skis slip. Ted has to wait until the back of his skis hold, but with this set up, his knee has to drop in, which is weak, it makes him late and hold on to the turn too long. Hirscher is on and off the edges fast, Ted is skiing too round because he can't get the immediate pressure on his skis he needs to be quick.