Leg extension machine

The leg extension machine zeroes in on your quadriceps muscles. If this exercise bothers your knees, try the modified version or choose a different exercise.

Getting set
Set the machine so your back sits comfortably against the backrest, the center of your knee is lined up with the machine’s pulley, and your shins are flush against the ankle pads. (On most machines you can move the backrest forward and back and the ankle pads up and down.) Sit down and swing your legs around so your knees are bent and the tops of your shins are resting against the underside of the ankle pads. Hold on to the handles. Sit up tall and pull your abdominals in. See photo A.
The exercise
Straighten your legs to lift the ankle bar until your knees are straight. Hold for a second at the top position, and then slowly bend your knees. See photo B.

Do’s and don’ts

• DO make sure that you take the time to set the machine properly.
• DO move slowly.
• DON’T ram your knees at the top of the movement.
• DON’T arch your back in an effort to help you lift the weight.

Other options
Modified leg extension (easier): If one leg is noticeably stronger than the other, slide one leg out of the way and do this exercise one leg at a time. You probably will need less than half the weight you use when lifting both legs together.
Single-leg extension: Many leg extension machines have a mechanism you set to limit the distance that you bend and straighten your legs. Use this device if your knees give you trouble at any point of the exercise.
Ball squeeze leg extension (harder): Place a soccer ball, weighted ball, or rolled towel between your knees. As you extend your leg, concentrate on squeezing the ball so it doesn’t slip out of place. This version of the exercise forces your quads to work harder in order to hold onto the ball.