Phone: 03 8822 3723

The Single Leg Squat Is The Best Leg Exercise For Knee Injury Rehabilitation

Written by: Nick Jack
Category: 2014
on 20 June 2016
Hits: 21206

Anyone who has had a severe or chronic leg injury, will know just how difficult it can be to do the simplest of movements or activities such as walking up stairs or getting in and out of cars. Even just regular walking itself can be hard! I should know, I have had more than my share of injuries. Most of my injuries have been on my left leg, and many of them could have been easily prevented if I had adopted the methods and exercise techniques I am going to share with you in this article. For these injuries were not bad luck, they were all postural and movement related. Plus the fact I did not rehabilitate them correctly and went straight back to playing sports, led to compensation and dysfunction, that created a new injury. Each time this happened I became much less stable and much weaker. It was only later in life taking on my current role, researching and learning from my mistakes, did I find the answer. And possibly the greatest answer has been the power of learning how to do a Single Leg Squat. The funny thing is that right now I am back to square one again...... And this time it is on my right leg for the first time ever. And this would be the most serious injury I have ever had - a partial tear to my ACL! I need to be able to get back to full stability and strength in order to learn how to walk and run again. And what better way to do this than with the single leg squat.

Where The Pain Is, Is Rarely Where The Problem Is!

I have covered this topic a few times in other articles relating to knee pain and back pain. But really it is true for every type of chronic injury, and even in some trauma injuries like my knee. For at the source of all these problems is two areas. The pelvis and the ankle. The pelvis in most cases started the ball rolling from postural problems such as tight hips and weak abdominal stabilizers, weak glutes and poor movement mechanics creating a multitude of problems down the line, or in this case the leg. At the other end lies the ankle and this also can create havoc for it moves in similar movements to the hip and can also send faulty alignments and movements up the chain. Often ankle problems are created from simple ankle sprains that are not treated and rehabilitated correctly. But in most cases it is the pelvis that started the problem and until that is resolved nothing is going to change.

To give you an example let's look at all the injuries suffered by my left leg.

  • Severe ankle sprains 5 times!
  • Osteitis Pubis
  • Grade 2 Hamstring tear
  • Plantar Fasciitis
  • Achilles Tendinosous
  • Patella Tracking
  • Hip clicking and instability

I had a 5cm difference with measurement to my quadricep versus my right leg. Basically I was in a lot of trouble for a long time suffering setback after setback. In all these cases I had Physiotherapy treatment that included massage, stretching and some simple remedial exercises like calf raises or tubing exercise. All of these treatments helped to take my pain away and after a few weeks, I was able to get back to what I was doing, only to suffer another problem again in a few weeks time. During this time I never injured my right leg once! I only managed to finally get on top of all these problems when I finally understood the importance of correcting my posture and learning how to move. (Which by the way was never taught or shown to me at any stage with all the different therapists I had seen). The most important thing I had to do was - learn how to move on one leg, for this is where all my issues were going to be found. I say this almost every day to my clients - "the activity or movement that is most likely to hurt you, is also the one you need to learn how to master". For if you master the one thing that can really hurt you, there is no real chance of being injured again! And in the case of my right knee currently going through ACL rehabilitation program the single leg squat is this movement!

But why is this so important? Can't I just use simple exercises like leg press, leg extension, leg curl, calf raise etc etc to build strength into my muscles? Stronger means the joint is protected right? No, not at all. For I also tried this in the early days only to develop more problems. Like I said earlier, I had to learn how to move correctly, with great balance, timing and progressing to more difficult movements that would replicate what I needed in my job and sports.

Machine training is without doubt one of the worst things you can do for any injury, for it weakens stabilizers and destroys good movement at the expense of trying to get strength. Watch our video below explaining the danger or machine training to see what I mean.

It Is All About The Glutes

It is funny that we are talking about the glutes (butt muscles) here and not the VMO or some quadricep exercise as most people are told to do for a knee injury. Again people look too much at just the area in pain instead of looking at what caused the pain. And in 90% of all cases it will have something to do with the glutes. These large powerful muscles are also very lazy and easily dominated by hip flexors and quadricep muscles wanting to overwork. This is where the injuries are usually born, and over time through countless repetitions of loading the quads which become more and more dominant, and the glutes becoming weaker and weaker that the joints now become exposed to injury! 

Use of simple isolation exercises such as the Clam and Hip Extensions are great introductory exercises to use, read our article on How To Strengthen Glutes for detailed instructions on how to do this or watch the quick videos below.

But you must understand that is all they are - "introductory exercises". They are not even close to actually building enough strength or stability that is required for injuries like ACL tear in my case. They are just a starting point. Remember earlier I said I had all sorts of trouble after Physio treatment when I went back to sports because this is usually as far as my rehab went. I was told to keep doing these and I would be right. But we all know what happened after that! The problem with the clam which many would regard as the best exercise for isolating the glutes, is it only uses one part of the glutes role. When in fact there are three parts that are used simultaneously in a movement like walking and running.

There is three distinct heads of the gluteus medius muscle that perform a unique role as the body moves:

  1. The posterior fibres contract at early stance phase to lock the ball into the hip socket. The posterior fibres therefore essentially perform a stabilising or compressing function for the hip joint.
  2. The middle/anterior fibres, which run in a vertical direction, help to initiate hip abduction, this is where the clam comes in which is then completed by a hip flexor muscle known as the TFL. The glutes work in tandem with TFL in stabilising the pelvis on the femur, to prevent the other side dropping down.
  3. The anterior fibres allow the femur to internally rotate in relation to the hip joint at mid-to-end stance phase. This is essential for pelvic rotation, so that the opposite side leg can swing forward during gait. The anterior fibres perform this role with TFL.

Basically we need an exercise that performs these three key functions in order to restore optimal movement and strengthen correctly. The exercise needs to stabilise the hip, act as a hip rotator, and lock the head of the femur into the socket, creating a very tight and stable hip joint during gait. This prevents the ball and socket joint from rattling around during walking and running. Can you see now how the isolated glute exercises used extensively in rehab settings, Pilates programs and even machines to isolate and strengthen are potentially creating more dysfunction and problems, instead of solving them!

What exercise would use all three functions of the glutes? You guessed it..... The Single Leg Squat! Here is how you do it and what to look for.

How To Do The Single Leg Squat & What To Look For

As we have already discussed the single-leg squat is superior to other movements for it uses all of the glute function but it also uses quadriceps, hamstrings, adductors and abductors along with help of core stabilizers and even the muscles around the ankle. This means that it is also a great test to use to determine where any leaks in the pipe may be hiding. It is always wrong to ignore a poor single-leg squat, as this movement shows you what will happen with the support leg during running. You might need the help of a friend or coach, or use a mirror to identify these mistakes. Video feedback is the best, and I like to use an App called Hudl Technique as it gives great slow motion detail and you can draw over the screen. Invaluable as a teaching resource with my clients, and even myself! First let's define the technique.

Correct Technique:

  1. Begin the movement by flexing at the hip and continue bending the knee and ankle until your thigh is as close to parallel to the ground as you can get it.
  2. Keep hands in front of the body.
  3. Keep trunk as neutral as possible, preferably neck above toes, avoiding excessive lumbar and thoracic curvature.
  4. Heel must stay in contact with the ground at all times.
  5. And MOST IMPORTANTLY make sure you ankle, knee and hip all line up in a perfect straight line.

There are a quite few things that contribute to poor single-leg squatting so here is a table highlighting what to look for.


For help with taping of the VMO or using exercises to target the VMO which is prone to weakness and laziness just like the glutes I have provided two quick videos below to help you.

You Must Progress To More Difficult Movements For Long Term Success

Now that know the technique and are able to execute correctly you MUST progress this movement with various skills. Strength is obviously one component but again it is only small piece in a puzzle of skills you need in order to be fully rehabilitated. Balance, Power, Agility are some of the more difficult skills to learn and ultimately where many answers lie. This is the mistake I made many times when I was younger by missing out on this type of training, so if you have read the article as far as here you are already miles ahead of me. Always remember you are constantly trying to force your body to adapt to new stimulus that is harder than what it can currently do. As long as it is safe and a gradual progression you will reap huge rewards. Most sports require the ability to jump off one leg vertically, laterally (sideways) and also be able to stop suddenly and change direction. This means that you must expose your leg to these skills and be able to perform as close to perfect as possible in the gym for you to be safe in the real world. This is true also to some extent to non sports players for even the movement of getting in and out of a car is similar to a single leg squat sideways. Very difficult to do if you have trouble with a single leg squat. I should know, for I found this extremely hard to do for 2 weeks after my ACL injury! There are countless ways you could progress and if you are someone recovering from a Knee Injury this is all covered in great detail in our Knee Pain Video and Ebook program you can get instantly as a Download by going to our online shop.

But to help you out here is a couple of videos using advanced sports exercises to give you an idea of how to fully prepare your leg.


I am sure you can agree now that the single leg squat is by far the best exercise for not only assessing compensatory movements but a particularly great exercise in it's own right for strengthening the entire leg. The timing it shares with walking, running and many sports activities mean it has a great carryover effect of teaching the body how to move efficiently without pain and restriction. The overuse of isolated muscle exercises by many rehab programs is so disappointing when just simply learning how to move correctly could have done a much better job in half the time. Learning to progress to more difficult movements needing more skills such as balance, power and even agility is critical in taking your body's ability to new heights.

If you have Knee Pain I highly encourage you to get a copy of Video and Ebook below by clicking here


If you would like more information we have heaps of Free Reports and cheat sheets you can download by going to our webpage called FREE REPORTS.

And if you live in the Melbourne area and would like to arrange a Free Consultation fill in the form below and I will get back to you within 24 hours to schedule a time