Your front thighs comprise a group of four muscles called the quadriceps femoris. One of these muscles, the inner vastus medialis, has a teardrop shape. This muscle extends from your mid-inner thigh bone down to your inner knee. It functions as a extensor of your knee. If that sounds confusing, just know that the vastus medialis is one of the muscles that lets you straighten your leg. When you do perform the leg extension exercise, you can do a slight tweak that will let you emphasize the work of the vastus medialis, so you can better strengthen this teardrop-shaped muscle.
Sit on a leg-extension machine with your back against the seat. Choose a light weight to begin the exercise. You need to do two to three sets of high repetitions, up to 25 reps, using light weights to warm up your vastus medialis and other muscles of your quadriceps femoris. These are the rectus femoris, vastus intermedius and vastus lateralis. You will also warm up a small knee muscle known as the articularis genu.
Slide your feet under the roll-shaped pads of the machine. Your knees should be bent past 90 degrees to place your quadriceps femoris muscles under a stretch at the start of each repetition. If this is not the case, adjust the machine until your knees are in this position.
Turn your feet outward, so you toes are pointing towards the outside. This is key for emphasizing the vastus medialis muscle. Keep your feet in this outward-facing direction throughout the whole range of motion to keep the main emphasis on this muscle.
Grip the machine handles for support. If by chance there aren't handles on the machine, grip the sides of the seat to give you that support.
Straighten your legs by extending your knees just short of locking out. By not locking out your knees, you keep the tension on your muscles. Stopping before your joints lock out is also safer for the knees.
Bend your legs by flexing your knees past 90 degrees, or until you return to the starting position. Do three working sets of 10 to 12 reps of this exercise once you complete the warm-up sets. Use moderate to heavy weights during your working sets so you can strengthen your vastus medialis and other quadriceps femoris muscles.
Tips & Warnings
- If you have access to an exercise bike, then cycle for 10 minutes at a relatively slow pace as part of the cool-down phase of your workout. You can also do a slow walk on a treadmill or outside if you can't access an exercise bike.
- Never ignore any pain you may feel while exercising, especially in your knees. Stop doing leg extensions if you experience knee pain and pay a visit to your doctor to get a checkup. Taking this proactive approach will help you minimize the risk and/or avoid serious injury.
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