A final thing the knee does is help save you from a crash. Sometimes, as the front end loses traction, you can push off the ground with your knee, and sometimes save it from low-siding. A low side is when your bike slides out from under you during a corner. This is the preferred crash, because you are already close to the ground, and you have a good chance of just sliding to a stop. Your front tire loses traction, and the bike falls away from you.
Low sides occur on the way into the corner.
These occur on the exits of corners, when the bike is being powered out of the corner. Usually, the back tire loses traction quickly, steps out to the side, then regains traction abruptly, tossing the rider over the bike. Besides hitting the ground from 5-10 feet in the air, there is an excellent chance that the bike will be right behind you.