The vastus medialis is one of the four quadriceps muscles, located on the front of your thigh, above your kneecap. It’s the innermost one. When you extend your leg fully, you can feel and sometimes see this muscle contract.

That section of the muscle that’s just above the kneecap is referred to as the vastus medialis oblique (VMO).

Your vastus medialis helps to stabilize your kneecap and keep it in line when you bend your knee. If you have knee pain or a knee injury, it may be due to weakness of your vastus medialis or other quadriceps muscles.

While you can’t technically strengthen your knees, you can strengthen the muscles around your knees to help stabilize the knee and avoid injury. Having a strong vastus medialis muscle will help prevent knee injury.

Here are some vastus medialis exercises you can do weekly at home or in the gym.

This exercise isolates your vastus medialis. Sitting tall with proper posture is very important with this exercise. If you feel yourself rounding forward, try sitting with your back, shoulders, and buttocks against a wall.

Equipment used: mat, wall, and ankle weights (optional)

Muscles worked: quadriceps

  1. Sit down on the floor with a tall posture. Your shoulders should be pulled down your back with your chest proud. Bend your left knee in toward your chest with your left foot flat on the floor. Extend your right leg in front of you with your foot pointing slightly out to your right.
  2. Hold under your left knee with both hands interlocked, and keep your right quad flexed for the duration of this exercise.
  3. Exhale. Without losing your posture or leaning away from the wall, lift your right leg up in the air as high as you can. Hold this position for 1 count.
  4. Inhale and slowly lower your right leg back down to your starting position. Try not to slam your right heel back down.
  5. Do 12 repetitions for 3 to 4 sets, and then switch legs. If you find this exercise fairly easy, add an ankle weight lying across the thigh (not on the ankle) of the extended leg, and perform the same exercise for the same number of repetitions.

Expert tip: If you aren’t able to lift your leg up at all, don’t get discouraged. It’s quite common, and just means you need to strengthen your vastus medialis.

You should, however, feel a contraction above your knee. Put your right hand on your right thigh just above the knee and a bit to the left. As you flex the quadriceps, you should feel the vastus medialis muscle contracting.

As you get stronger, you’ll be able to lift your leg up off the floor.

This move helps strengthen muscles in the front and back of your legs and your lower back, which helps you lunge and squat properly without knee pain. Both legs will be strengthened at the same time in this exercise.

One leg will always be pushing off the step, while the muscles of the other will be contracted and controlling the descent during this exercise.

Equipment used: stepper and ankle weights (optional)

Muscles worked: quadriceps, glutes, hamstrings, and calves

  1. Stand tall with your left leg straight but not locked and your right foot resting on a small step. Your right knee should be slightly bent, and your left foot should be flat on the floor. Your right knee shouldn’t be going over your toes. Squeeze your core for balance.
  2. Exhale and push up off your right leg until both legs are fully straightened. Try to keep your hips level as you step up.
  3. Inhale, contract your left quadriceps, and slowly lower your left foot back down to your starting position.
  4. Repeat 15 times for 3 to 4 sets, and then repeat with your left leg on the stepper and your right leg on the floor, controlling the negative part of this movement.

Expert tip: Use a small step. You don’t want to feel any pain in either knee.

If you’re confident with your balance, you can step your left foot off the step and hold before you start the movement.

Start with a low step to ensure comfort in the knee joint. You can always progress to a higher step, as shown, when you feel more comfortable and your muscles get stronger. As with the previous exercise, this move will strengthen both knees at the same time.

Equipment used: stepper, and ankle weights (optional)

Muscles worked: quadriceps, hamstrings, and calves

  1. Stand with your right foot on the step and your left foot off to the side.
  2. Inhale. Flex your left quadriceps, and bend your right knee until your left foot is flat on the floor. Again, try to keep your hips level at all times.
  3. Exhale, engage your core, push off your left foot, and come back to your starting position.
  4. Repeat 15 times for 3 to 4 sets, then switch legs.

You can perform this exercise at home with a chair and a resistance band or on a leg extension machine. However, you’ll modify the leg extension motion, as the way this machine is typically used puts too much pressure on the knee.

This exercise takes the first exercise, the floor extension, to the next level, with added weight.

Equipment used: a chair and a resistance band or a leg extension machine

Muscles worked: quadriceps

  1. Sit tall in a chair, and scoot yourself to the front of the seat.
  2. Wrap a resistance band around your ankle, and feed the band under the chair, which you’ll then reach back and grab with your hand.
  3. Exhale and in one motion slowly extend your leg to full extension out in front of you.
  4. Inhale, contract your quadriceps, and slowly lower the leg back down to 30 degrees.
  5. Perform 15 repetitions for 3 to 4 sets. Remember to keep that 30-degree angle until your knee is healthy again.

This exercise can be performed anywhere with or without equipment.

Equipment used: mat or flat surface, towel, and ankle weight (optional)

Muscles worked: quadriceps, hamstrings, calves, and glutes

  1. Lie on your back with your left knee bent and your left foot flat on the mat. Fully extend your right leg out in front of you, placing an ankle weight on your thigh, if desired. If this is your first time performing this exercise, don’t use a weight.
  2. Squeeze your core, contract your right quadriceps, and lift your right leg about 2 inches off the mat. Keep it elevated for the duration of this exercise. Make sure you’re not arching your back. You don’t want any space between your back and the mat.
  3. Inhale. With your right quadricep contracted, raise your right leg up until your right thigh is even with your left thigh. Hold this position for 1 count.
  4. Exhale and in a slow controlled manner, lower your right leg down to your starting position, keeping it about 2 inches away from the mat.
  5. Repeat 15 times for 3 to 4 sets, then switch legs.

Expert tip: It’s important to raise your right leg only as high as your left thigh. If you raise it any higher, you’re not strengthening your knee, you’re challenging your hip flexibility. That’s not what this exercise is for.

Equipment used: 2 resistance bands

Muscles worked: quadriceps

  1. Tie a resistance band around a sturdy anchor, and slide the other end up to slightly above the back of your right knee, facing the anchor. Step back until the band is taut. Straighten your left leg, and keep your right knee slightly bent.
  2. Exhale and push your right knee back to match your left knee, and really exaggerate the contraction in your right quadricep. Again, you want to see or at least feel the vastus medialis tightening and contracting. Hold this position with resistance for 1 count.
  3. Inhale and slowly release the tension in the resistance band, bending your right knee back to your starting position. If you didn’t feel any resistance in your vastus medialis, grab a thicker band or move farther away from the anchor, making the band more taut.
  4. Perform 15 repetitions for 3 to 4 sets, and then repeat on your left leg.

Most people experience knee pain at some point in their lives. Strengthening the muscles and ligaments around your knees can help stabilize and protect your knee.

This workout was created by Kat Miller, CPT. She’s been featured in the Daily Post, is a freelance fitness writer, and owns Fitness with Kat. She currently trains at Manhattan’s elite Upper East Side Brownings Fitness Studio, is a personal trainer at New York Health and Racquet Club in midtown Manhattan, and teaches boot camp.