1. This movement is performed with a Smith machine.
2. Stand with your feet shoulder width apart, knees slightly bent. With the bar on the smith machine, step underneath and position the bar across the back of your shoulders. You should position your stance slightly infront of the bar. Keep your head up. Place your arms on either side of the bar.
3. To be able to use the Smith Machine Bar, you must unlock the bar from the hooks, this is usually performed by twisting the bar. Now, keeping your head and your back straight, lower yourself by bending at your knees. Once you are parallel with the ground, pause and without bouncing return to the starting position. Be sure to push with your feet including your heels flat on the ground. Also, do not lean forward if possible.
4. Slowly, come back up to the starting position.

This is one of the best movements for developing overall thigh shape. Performing squats with a Smith Machine allows you to isloate your quadriceps while taking away much of the strain from your lower back and knees. This exercise is great, especially to develop mass and strength in the front of the thigh, the quadriceps. It is very important to keep a few things in mind. Always keep your back flat and your head up as well. Also, push with the heels of your feet, this will take stress from your lower back and target the quadriceps more effeciently. Good Luck!