1. Sit on the leg extension with your back firmly on the back rest.
2. Press the back of your knees firmly against the edge of the seat.
3. The leg extension pads should be set just above your ankles. Place your ankles under the extension pads. Keep your head level and place your hands on the grips.
4. Slowly raise the weight by extending both legs upwards to the straightened position. Do not jerk the weight up.
5. Hold this position for one second. Slowly lower the weight back to the start position. Repeat movement.
The leg extension is a pure isolation exercise for the front thighs. No other muscle group is used during the completion of this exercise.
This exercise is all about concentration and contraction. What you want to do is concentrate on squeezing at the top portion of the movement and going up nice and smooth.
I personally use this exercise as a warm up for my heavy squats. This is a great exercise to get your knees and front thighs ready for squats.