How to do a single leg squat

Runners D.I.Y. Injury Prevention & Rehab – Part 1

Runners D.I.Y. guide to injury prevention & rehab.

Part 1: Knee Pain A.K.A. Patellofemoral Pain Syndrome


Injury prevention and rehabilitation are lengthy and specialised subjects requiring knowledge and skills on many levels. However, we’ll try and break it down with some useful info and guidance to help the interested runner gain more personal knowledge of their injury or rehabilitation needs.

Please note: At Pete Fraser Fitness we refer any client with chronic, highly painful or complicated symptoms to seek the advice, guidance and treatment of a medical professional in the first instance. Nothing replaces the correct diagnosis from a chartered physio or sports physician.

Let’s start with some basic info on biomechanics and running gait – you need to walk before you run, right? Let’s take a closer look at knee pain…


The running kinetic chain

Proper running mechanics involves a synchronous movements in all of the kinetic chain – in other words the arms, spine, hips and legs all need to `talk to each other and get on happily`. If any of these components are not synchronised, or `talking to each other`,injury is a likely outcome.

In the case of knee pain, unless you’ve had a direct impact to the knee it is likely your knee pain is the result of an overuse injury and probably not the direct cause of it. Other weaknesses and imbalances in the kinetic chain may be the cause.

The point above is important and may often be overlooked.

So if my kinetic chain is out of sync, what is the cause of the pain if not the knee?

The knee pain maybe an outcome of weak hip stabilisers causing the illiotibial band to become tight and producing uneven stresses at the knee and the outcome is knee pain.


The above example in equation form: weak gluteus medius + tight illiotibial band + weak inner quads = poor knee alignment and knee pain

Incidentally, knee injuries have been reported to make up approx 50% of all running injuries


Back to the knee pain. A specialist will assess all of the lower kinetic chain to find the imbalance not just go straight to the knee and treat it in isolation which would do nothing to correct the root problem.

If you have mild knee pain which has which you’ve noticed has become worse over a period of time, chances are you have patellofemoral pain syndrome or `runners knee`.

You should also take note of other factors:

  • Have you recently increased your training volume or intensity
  • Using new shoes
  • Running on a different surface
  • Been injured recently, other than the knee pain, i.e. ankle sprain

Take note of these changes and decide if they may be a contributing factor.



So what do you do about it?

As we’ve already said, ideally go see a sports physiotherapist. Alternatively try these assessment and treatment techniques over a 2 – 3 week period and note any improvement.

Stage 1: Assessment

One of the best assessment techniques to determine pelvic/lower limb weaknesses or imbalance is something that you can easily and effectively do at home. BTW, it is also an excellent strengthening, rebalancing and stabilising exercise built into one – what is it?

The single leg squat

What does it do for you?

Primary muscles worked: Gluteus maximus, gluteus medius, quadriceps.

Secondary muscles worked: Lower back & spinal supporters, hamstrings, ankle stabilisers and movers.

Benefits: Develops a strong lower kinetic chain: pelvis, upper and lower legs, ankles and foot. Strengthens the main dynamic and postural musculature of the lower limb. Improves stability and balance.

Here Pete is performing a single leg squat on a bosu for added stability and balance development.

How to do a single leg squat

As an assessment tool

  • Wear minimal/tight fitting clothing (so you can see the pelvis and knee clearly) and no shoes
  • Stand in front of a full length mirror with feet hip width apart and parallel
  • Stand on one leg and lower yourself as far to the ground as possible and return back keeping balance
  • Look at the hips: if the squatting leg side hip lifts above horizontal and the lifted leg hip drops below horizontal, it may mean you have weak gluteal muscles
  • Also, look at the knee: if the knee `wobbles` as you squat down/up, again the gluteals may be weak

OK, so now you’ve assessed and found imbalance at the hips and possibly an unstable knee. So how do you start correcting it?

Stage 2: Stretch the illiotibial band

Click here to learn how to use soft tissue rollers and stretch a tight illiotibial band (ITB). This is one of the first stages in correcting imbalance at the hips and knee. A tight ITB can cause poor alignment of the kneecap and result in pain at the knee. Stretching the ITB will allow the upper leg musculature to contract in the correct pattern of movement.

Here’s Pete performing an ITB stretch on a trigger point roller. He is not smiling – it’s a grimace!!


Stage 3: Strengthen the leg and hip muscles

You need strong glutes to stabalise the hip and knee which also keeps the knee positioned correctly and makes you a stronger more balanced and powerful runner.

You need strong glutes to stabalise the hip and knee which also keeps the knee positioned correctly and makes you a stronger more balanced and powerful runner.


How to do it?

Use the single leg squat: …….

  • Ideally stand in front of a full length mirror
  • feet hip width apart, feet parallel
  • lift one foot off the ground and keep it raised
  • lower yourself down (over the count of 3 seconds) as far as possible keeping hips level and knee in line and behind the toes as you look down
  • lift back to the start position (counting 2 seconds) keeping the knee and hips aligned in the same way
  • repeat for 10 – 20 reps x 3 sets, resting for 1 min between sets


  • important: keep hips horizontal and the centre of the knee cap in line with the second largest toe
  • try and feel the glutes and quads contracting and working
  • keep the foot stable – ideally perform barefoot and refrain from `gripping` toes into the ground
  • don’t forget to breath!!

How to do a single leg squat on a bosu with added resistance

Single leg squat with resistance


  • extend the supporting leg forward and lightly tap down the heal at the lowest part of the squat before returning to the top
  • extend the supporting leg out to the side and reach as far as possible as you lower down, lightly tap the foot on the ground before returning to the top
  • as you squat down rotate the hip 90 degrees to the lifted leg side – combining the squat and a hip rotation, at the fullest rotation and deepest squat position return back to the top
  • for added stability and balance training, use a bosu like in the image above
  • for increased strengthening hold some 4/5kg dumbbells to the side of the hips

More common running injuries and how to rehab them coming soon. If you found this useful, email us! 

If you’d like us to cover any specific rehab or performance topic, email us!