The Petersen Step Up is a proven way to isolate and strengthen the VMO (the inner “teardrop” shaped muscle of the quads).
The ability to strengthen the VMO so effectively means the Petersen Step Up is not only a great way to build muscle in this part of the body, but it is also an incredibly useful way to combat MSK knee injuries like Jumper’s Knee and Runner’s Knee, as it improves kneecap tracking.
The exercise, however, is quite tricky and there are multiple phases to the movement that you need to master to properly target this part of the leg properly.
In this exercise guide, we explain how to perform Petersen Step Ups properly, the benefits, alternatives and things to consider before you add it into your next workout.
What is a Petersen Step Up?
The Petersen Step Up (or Step Down) is a unilateral leg exercise that focuses on strengthening the quad muscles around the knee joint.
The exercise was first introduced by Carl Petersen, a Canadian Physiotherapist who worked for the Canadian National Alpine Ski team. The movement helps to isolate and strengthen the VMO (Vastus Medialis Oblique), which plays a vital role in knee function and health.
Particularly for knee injury recovery, the ability to strengthen the VMO helps to ensure the knee joint can be extended fully.
From runners to weightlifters, the Petersen Step Up can also be a powerful way to progress strength training and improve overall performance.
Petersen Vs “Peterson” Step Up
How to Perform a Petersen Step Up
To do Petersen Step Ups:
- Stand on a raised surface, such as a stepper or barbell plate.
- A 3 inch height is a good starting point (the higher the raised surface, the more difficult it becomes).
- Place one foot on the edge of the raised surface so that your other foot hangs off the edge.
- Your feet should be roughly shoulder-width apart.
- Slowly lower your foot down to the floor, with your toes pointed by bending the leg of the foot that is on the raised surface.
- As you lower this foot to the floor, raise the heel of your other foot that is on the raised surface.
- Pause for a moment before straightening this leg again by pushing down on the foot that is on the raised surface whilst lowering the heel and bring your other foot back up to the starting position.
- The focus should be on pushing down through the leg that is on the raised surface, and not the one that is lowered to the floor.
- Repeat for repetitions (8-12) and repeat on the other leg.
Coach’s Tip – Try and align the heel of the lowered foot with the toes of the foot on the raised surface. This will encourage a good movement path and kneecap tracking.
The primary muscles worked in the Petersen Step Up are the quads, particularly the VMO (Vastus Medialis Obliques).
The VMO is the “tear-drop” shaped muscle around the knee joint.
The movement will also engage the glutes, hamstrings and calves to support the movement.
Due to the exercise being unilateral, it will also work your core to maintain stability.
The root cause of common knee injuries like “Jumper’s Knee” is often associated with an imbalance between the outer quads (Vastus Lateralis) and the inner quads (Vastus Medialis Obliques).
Some sports and certain repeated movements may encourage more development and strength of the Vastus Lateralis in comparison to the VMO, which makes the knee more vulnerable to injuries due to poor kneecap tracking.
Imbalances between any muscles that work together to perform a function risk causing MSK problems… and the quads are no exception.
By strengthening the VMO, it helps to address potential imbalances which improves kneecap tracking and reduces the risk of associated knee injuries.
It can be quite hard to find exercises, especially bodyweight movements, that effectively train the VMO compared to other parts of the quads, which is why the Petersen Step Up is often one of the top recommendations (and why it features so heavily in training protocols like ATG’s Knees Over Toes program).
The Petersen Step Up is a unilateral exercise which means each side is trained separately. This helps avoid one side overcompensating for the other.
If your leg workout consists of squats, deadlifts, leg press, and other bilateral exercises, including some single leg variations is definitely a wise choice.
Due to the movement being unilateral, it will also require a good level of balance and stability, especially when you lift your heel up. These sorts of attributes are vital for healthy aging so including them in your workouts will help with better overall functional movement too.
If you’re struggling to keep balance, don’t worry and just hold onto a wall for support and start with a low raised surface and slowly work your way up.
As well as being a great way to isolate the VMO to help aid knee injury recovery and prevention, the ability to isolate the VMO means those looking for increased hypertrophy (muscle growth) in the inner front quads will also be interested to give Petersen Step Ups a go.
Regression (Poliquin Step Ups)
Charles Poliquin was a big believer in the Petersen Step Up, but wanted to adapt the movement to make it easier for beginners… which led to the Poliquin Step Up.
This movement involves using a slant board or slanted surface, instead of lifting and lowering the heel of the foot on the raised surface. The angle of the foot also means this doesn’t require as much ankle mobility, which could be a limiting factor for some.
The Patrick Step Up is another similar modification that doesn’t involve the lift of the heel.
A simple way to add progression to the Petersen Step Up is to hold additional weight as you perform the movement, such as dumbbells or a barbell. We would only recommend this once you can do 3 sets of 8-12 repetitions comfortably.
Another way to add progression would be to increase the height of the raised surface. This will increase the range of motion at the knee joint and require more strength to straighten the leg when the lowered leg is touching the floor.
Things to Consider
If you are experiencing any sort of knee pain or discomfort, we would recommend seeing a Physical Therapist or healthcare professional to help get to the root cause of your pain. In some instances, exercises like the Petersen Step Up may not be recommended.
It’s also importance to stress that although the movement looks quite simple, it is challenging, so only add additional weight when you can comfortably perform the exercise and want to increase the difficulty.
If the Petersen Step Up is proving slightly too challenging, we’d recommend opting for the Poliquin Step Up to help simplify the movement.
Any sort of step up will share a similar movement path to Petersen Step Ups.
Our guide on the best step up alternatives also includes a list of exercises to try that work similar muscle groups.
We also recently published a guide on Spanish squats, which is another effective movement in Physical Therapy that helps to address Jumper’s Knee.
The recent popularity of Knees Over Toes training is largely due to the effectiveness of exercises like the Petersen Step Up.
You don’t need any equipment to get started, and if you’ve ever experienced knee injuries like Jumper’s Knee, you may find it becomes a key component to your weekly fitness routine.
Not only does it help to strengthen the VMO, but it also tests your balance and stability, as well as coordination.
We would recommend starting with a low stepper height and slowly increasing the height to increase difficulty as you feel more confident in the movement.
The exercise offers benefits to anyone, but we would say is it best suited to anyone specifically looking to address knee problems or athletes looking to protect their knees during sports.
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Featured image and video credit – Milo Performance and Education