|How to do:
1. Sit on the seat of a leg extension machine with the foot pad firmly placed on the inner part of your ankle. Make sure your knee is flexed at a 90-degree angle. If your leg is forced too far beyond this, knee damage can result early in the movement.
2. Extend and straighten your lower leg.
3. This is the only leg exercise that you can lock your knees out without risking damage. After reaching the end of the motion, pause a moment and slowly return the weight to a point near the starting position.
4. Pointing your toes toward each other at a 20 degree angle works the inner Quad area while pointing your toes outward works the outer Quad area.