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Top 5 Strength Exercises For Patella Instability

Written by: Nick Jack
Category: 2014
on 13 August 2018
Hits: 42320

If there is one thing I am asked almost every day is, "what are the best VMO exercises for my knee". And I must admit I hate writing these articles that label things the "best" as there is no definitive best exercise for everyone, only the best exercise for you. Some people the missing ingredient may in fact be stretching or a mobility drill, others it may be a technique tip with how they squat or run, and others it may be strengthening an area that is very weak. The real secret to knee pain and patella instability is identifying your weakest link using in depth assessments, and the results of these tests will determine your program. If you do this right you will find the real problem is not anywhere near the knee! Having said all that I am going to share with you in this article the 5 most effective and commonly used VMO exercises I have successfully to treat knee injuries over the last 13 years as a rehabilitation trainer with both sporting athletes, and everyday people with knee pain.

To Effectively Work The VMO You MUST Be Standing Up

If there is one big mistake I see with so many VMO exercises that are prescribed by trainers, therapists and shown endlessly on videos in You Tube is that they try to isolate this muscle lying down. The reason people do this is thinking about where the muscle is located and trying to use an exercise that activates believing it will make it stronger and protect the knee. I myself made this mistake many years ago when I had all types of patella tracking problems with my left knee and a physio prescribed several isolated drills. I thought I was doing great stuff but all I ended up with was a hip impingement 12 months later that took twice as long time to get rid of. I also had used this with clients with knee pain as this was all I knew. I realized I had to find a better way as these exercises were causing more trouble and not helping anyone, especially myself. Now if you are not sure where the VMO is located or what that even stands for here is a definition.

VMO stands for vastus medialis oblique and is an extensor muscle located in the inner thigh area close to the knee. The vastus medialis is one of the four quadriceps muscle group.

Why is it such a big mistake to do this exercise lying down? Surely if it gets stronger performing it's role of leg extension it will make all the difference right? Why not use a leg extension or leg press?

The big problem with these exercises is they fail to understand two things.

  1. Firstly the weakness at the VMO is due to a problem at either the foot/ankle, the hip, or from poor motor control and coordination. Ignorance to the cause of the problem is massive in today's treatment of injuries and this is one of the  instances this mentality is used all the time. Always ask WHY is this muscle weak before rushing into exercises.
  2. Secondly many of the lying exercises are in fact more adductor and hip flexor strengthening, which are actually the main problem causing the VMO weakness and poor alignment of the knee in the first place!

These were exactly the mistakes I made many years ago and I wish I knew then what I know now as it would have saved me a lot of pain, time and money. Machine training like leg extension and leg press are best avoided as these sacrifice stabilizers in order to move. It is the lack of stability and coordination that is the whole problem. Read our article - Squats vs Leg Press to see more on this.

These may indeed activate the VMO in a small way, but they are completely useless and actually counter productive to what they are being used for! For all of these exercises are also hip flexor and adductor (groin) strengthening exercises that are going to contribute greatly to poor alignment and a continuation of patella tracking and knee pain.

The idea that adductor muscles can activate the VMO exercise has been refuted by countless studies over many years. And if you still don't believe me, observe what happens when people squat with adductors squeezing in and collapsing at their feet. This is a common problem we see in females and why their incidence of ACL injury in sports is so high. The lying exercise in particular is a real concern as this does not even include the VMO's role of knee extension. This is purely hip flexion with an exaggeration of adductor work. A perfect recipe for creating dysfunction that leads to ongoing knee trouble and eventually a dreaded ACL injury!

And even if you were able to improve your strength at the VMO using these exercises, this means nothing in terms of how you stabilize the leg in a single stance. Standing on two feet or lying on the floor does not expose the stability requirements of the feet and hip. And this is where you secrets lie in correcting your problem.

I don't mean to ridicule the person featuring this video for just like me her intention is to help people and that is a great thing. Unfortunately we need to have a better understanding of how our body really works to provide answers to correcting the source of the problem.

Below are 2 videos where I explain why the isolating the VMO is a waste of time.


What Can You Do?

As I mentioned earlier I have come a long way since mucking around with isolated exercises. And we have shared countless videos and articles before on VMO strengthening, Knee Pain and ACL injuries that I suggest you take a minute to read.

There is also many great FREE REPORTS & CHECKLISTS you can get that will fill in the gaps of things left out of this article. But if you are really struggling with knee pain I highly recommend getting a copy of our online program that comes as a 60 minute video and PDF report. This was put together several years ago to show you how to implement the assessment process to identify mobility & stability restrictions along with movement pattern dysfunction creating your knee pain. These programs provide over 70 exercises and teach you how to design your own program based on your test results to correct your weakness.

Click here to go straight to the online shop or on the image below to see more.

Okay let's take a look at our Top 5 exercises. I have ranked these in order of easiest to hardest. Bare in mind that there is really over 100 exercises I may use these would just fall into my category of providing the greatest benefit to the majority of people.

1: Toe Touch Drill

This is a very simple drill and a great assessment tool in it's own right. The reason I like this drill so much is that incorporates movement in all directions and demands you find the stability and control to stabilize the knee. This is more of a stability exercise than a strength drill and this is where you first begin to see any weakness at the foot or glutes, and poor hip mechanics and coordination with movement. This is best done barefoot and in front of mirror to observe any loss of alignment.

We use this assessment for all lower limb injuries and walking impairment as it requires massive stability and mobility in order to complete effectively.



  1. Standing upright with good posture on one leg. Imagine your are on the centre of a clock face.
  2. Drawing your belly button inwards bend your knee ensuring that your knee tracks over your second toe whilst reaching forward with the other foot to touch 12 on the imaginary clock.
  3. Repeat the movement touching each number on the clock from 1 through to 7 and back again maintaining a good upright spine position and keeping your pelvis still.
  4. Perform on the other side.

I may even progress this from a simple drill like this to a more complex drill where it simulates the activity of walking. We use this quite a lot with clients with walking impairments. See video below.

Mastering this drill then allows you to progress to the next level which is..... the single leg squat!

2: Single Leg Squat

This is arguably the hardest of the exercises but it must be used early on as it really is the secret to strengthening the VMO in accordance with it's partners in movement being the feet, ankle and hips. We would regard this as the "king of glutes" exercises which is critical for maintaining optimal knee alignment.

All you have to do to appreciate how good this one exercise is as a test is to observe all the things going on as shown in the video below.


There are so many things that must happen within a blink of an eye in order to maintain perfect stability and timing with this exercise. The fact that the brain will use the timing from this exercise in walking, running and jumping means you have to become great at this to prevent injury and improve performance, no matter if you are a sporting athlete or an elderly person looking to remain mobile! When assessing this movement we start at the ground and work our way up, looking for clues as to where joints are not functioning correctly. We can assess the feet for stability, ankle for mobility, hip for mobility and pelvis for stability all at the same time. Even the thoracic region can contribute to faulty loading. Last but not least we cannot forget the brain. The most important factor to consider and the one thing that drives all movement. You could actually find that all of these joints with the corrective exercises and drills are very good and there is nothing wrong with them! The problem is that you just do not know how to squat, which is a brain and coordination problem.

Spend the time to get this exercise right and it will pay off in buckets later on!

If you find this too hard I like to use this next exercise as a regression and stepping stone to single leg squats.

This exercise reduces the range of motion of the squat to a partial range so that you can focus solely on the area of weakness in the quadriceps which is just above the kneecap itself. 

I also introduce the band pulling the femur and hip inwards to force external rotation contraction from the glutes and therefor maintaining the optimal alignment of the lower limb. The stability this time is assisted by using a bench to allow for greater workload with the quadriceps.

It is important in this exercise to not lean forwards as you would normally do so with the squats and deadlifts. By removing any hip movement it forces all the work into the knee itself which is normally a bad thing to do, but in this case we are trying to create a bigger workload to the weakened quads. As long as you finish off learning good form with full range of motion these exercises are beneficial. Where they backfire is when people think this is the better way to squat.

3a: Balance Board Squats

This exercise will create some controversy in some circles as many believe these types of exercises are abused and create more problems instead of developing strength. I have found that learning how to execute this exercise perfectly before progressing to the strength exercises invaluable, not for the balance though.

The huge benefit to learning this exercise is two key things:

  1. Developing the ability to maintain trunk posture and stability which is crucial later in avoiding shoulder sway we see in change of direction in sport
  2. Correcting any leg strength difference between left and right leg that is undetected in other squats.


This exercise is unique in that in order to achieve a squat without the board hitting the floor you must be precise with your posture, stability in every joint and be even in your weight distribution. On the floor you can get sloppy and get away with it. With the balance board you cannot as the exercise provides constant feed-back as to how you are going. The risk of injury is minimal as there is no load being used, as opposed to a barbell that can exacerbate problems and even cause pain if you compensate too much. I like to use a holding tempo when doing this exercise, 5 second hold at the bottom without the board touching the ground.

Reps of 6-8 is enough and by this stage most people are feeling the quads big time. A great exercise for any sportsperson looking to improve balance on the field or court, and one we use a lot in our sports specific programs for snowboarding, tennis, basketball and football.


1. Stand on a balance board in a squat stance
2. Slowly lower into a squat making sure you maintain upright posture
3. Hold this position for 5 seconds with minimal contact between the board and the floor.

3b: "Off Center" Balance Board Squats


The progression of this exercise is where we place one foot close to the middle. This makes the board much more unstable and actually turns this into a single leg squat! The reactivity and strength needed to execute this squat is much greater but the benefits to this are remarkable as it will set the foundation for the more advanced hopping drills in number 5. Instructions are the same as above except for the change in foot position.  Here is a quick You Tube Video to see this in action.

4: Band Resistance Deadlift & Box Step-up

This is where I love to use resistance bands to force the VMO to activate within an integrated movement.

If a person has significant weakness at the glutes or even simply a poor understanding of movement to keep a well aligned knee, the body is forced to find another way to maintain this alignment. What it will often do is move the foot onto the outside part of the foot, which solves the problem of faulty knee alignment, but ruins your ability to stand up well balanced as you have only half of your foot on the floor. If the foot pronates to neutral like it is supposed to, the hips roll inwards forcing the knee into the horrible position again. 

Firstly, I start with the single leg deadlift and expose the knee to forces at both the hip or the foot as seen in the videos below.


The second exercise to use is the box step-up.

Step ups can be one of the hardest exercises and movements to do when you have chronic knee pain. But getting this movement back is essential if you want to be able to walk up and down stairs with no problem. This also highlights the difference in strength between the legs which is sometimes hard to detect in a squat.


1. Fix rubber tubing to a pole or have a friend hold a band while you tie the other end around your leg just under the knee.
2. Standing with good posture with one foot on a step box and your arms in a relaxed position.
3. Drawing your belly button inwards explosively step onto the box flexing your opposite hip to lift your knee up.
4. Pause then lower stepping backwards off the box.
5. Pause before repeating the movement

You can also progress this to weighted step ups. I start with weight vests to begin with so the person can keep the arm swing which is crucial in the power phase. I also like to use the variety of barbell on the shoulders to encourage strength and stability. This is a very difficult exercise for many to do so take care!

5: Decline Board Squats

Using a decline board or ramp squat can be great for improving VMO and overall quadricep strength. I will explain why in detail below, but firstly here is how to do it. Also it is wise to add the small micro band when first learning this so you can ensure your glutes are on the job and also the knee alignment is as close to perfect as possible.


  1. Standing with a barbell resting on your upper back hands slightly wider than shoulders with your feet on a ramp or heels resting on small weight plates.
  2. Lift your chest up to activate your upper back muscles and drive the elbows forward. Take a comfortable stance wide enough that allows you squat down between your legs.
  3. Take a deep diaphragmatic breath then draw your belly button inward.
  4. Lower down into a squat as low as you can keep the natural arch in your low back and no pain in the knee
  5. Exhale through pursed lips as you return to standing.

There has been many studies completed to evaluate the success of using this. One study featured in a book by Peak Performance found

“The research used elite Australian volleyball players with patellar tendinosis in a randomised controlled trial lasting 12 weeks, with a 12-month follow-up. Participants had to complete their exercises twice a day for 12 weeks. They performed 3 sets of 15 repetitions during a session. All exercises were completed on a single (affected) leg to about 60 degrees of knee flexion, with participants being taught how far to squat down during their initial session. Participants progressed load by adding weight to a backpack in 5kg increments. The group used a 25-degree decline squat board. They completed the downward component (eccentric phase) of the squat on the symptomatic leg, and the upward component (concentric phase) on the asymptomatic leg. They were instructed to exercise into moderate tendon pain and to progress by increasing load if this pain eased. By the end of the 12-month follow up period, there was a significant improvement in the ability of this group to carry on their full sporting activities com-pared with a control group who had undertaken a more conventional rehab program.”
Research reported in MA Young, JL Cash et al, ‘Eccentric Decline Squat Protocol for Patellar Tendinitis in Volleyball Players’, Br J Sports Med, 39 (2005) 2, pp 102-105

You will find more detail about this exercise in the article - How To Use The Decline Board For Improving Quad Strength

BONUS Exercises For Sporting Athletes Only

Lastly I have provided you with some complex drills that incorporate VMO strength and maintenance of knee alignment at HIGH SPEED. These exercises are not relevant to a person who does not play sports as they are unlikely to ever need this skills so these exercises would be risky. However if you do play sports it is risky to NOT DO these exercises. For you may be great at all the things we have seen so far only to fall apart when your body demands you to move at high speed.

These exercises make up our return to sport criteria for anyone following ACL surgery or any lower limb injury for that matter. I encourage you to read our full article - 5 Critical Things You Need Before Returning To Sport.

Any small weakness or problem with the other exercises is exacerbated here in a big way. Below is two of the simple tests we use to evaluate motor control and stability of the knee in preparation for sport.


To assist in getting many of the complex single leg exercises right you must have great glute activation. To help you with this I have provided you with a copy of our FREE Glute Checklist which you can download instantly by clicking the image below.


I hope you have enjoyed this article and see that strengthening the VMO for patella instability is much more than simple leg lifts or leg extension. Again I could provide you with over 50 more great exercises but I think you get the idea of learning to stabilize with single leg is the key, paying great attention to hip mobility, ankle mobility and foot stability all the time. Progressing from simple stability drills to more challenging movements and eventually strength training is where your body will learn how to incorporate the VMO in all lower limb movements.

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About The Author

Nick Jack is owner of No Regrets Personal Training and has over 14 years’ experience as a qualified Personal Trainer, Level 2 Rehabilitation trainer, CHEK practitioner, and Level 2 Sports conditioning Coach. Based in Melbourne Australia he specializes in providing solutions to injury and health problems for people of all ages using the latest methods of assessing movement and corrective exercise.


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