Got knee pain? Knees caving in during a squat? 

Quite often, we demonise the position and blame weak musculature. Cue glute bridges, crab walks, clams and many other variations of glute exercises. A good chunk of the time, there is success with this but unfortunately the success rate isn’t 100%.  

What then? Perhaps we look at ankle mobility, leg strength, hip mobility. Again, tends to have success.

But what if this doesn’t work?

What if, no matter how strong my glutes test on dynamometry, no matter how far I can go during a knee to wall test; my knees cave in during my squat and they hurt. What then?

Perhaps if we ask a different question, such as, why would my body resort to knees caving in during a squat we get a different answer. 

One of the fundamental principles to movement and more specifically moving against gravity is pressure management. 

One element of this pressure management is managing the direction your organs travel with movement. If my intention is to go up, but I am unable to elevate my organs to head in the same direction, then I am going to have a hard time moving upwards.

A good way to get a sense of this process in action is to jump with a water bag. It is much harder to jump up while the water is travelling down, than it is if the water is travelling up while I jump. If the water is travelling down while I try to jump up, I need to apply more force/pressure from below to travel upwards.

The image below is a 2D simplified version of this process playing out internally. The blue squiggle represents the organs. To move them up, I need to be able reduce the width of the line they are sitting on to elevate it and effectively push them up; added bonus if I can open the space above (around the rib cage) to give them an easier space to move into.


In an ideal scenario, I would have capacity of pelvic floor musculature to contract effectively to enable this process (reduce the width of the line and elevate it). If I can’t, this would start to resemble the water travelling down in a water bag situation described above and a need to increase pressure from below to overcome the downward momentum of the organs.

Squeezing the legs together ie. the knees caving in becomes an effective option in this case to increase the pressure from below and referencing our 2D example from before, reduce the width of the red line to elevate it. 

If I can improve capacity at the pelvic floor, then there is less need for compensatory actions through the legs and in turn, less valgus stress through the knees.

By no means do I suggest this is the magic answer and most things tend to be multifactorial. But if the tried and traditional hasn’t worked for you, not all hope is lost, perhaps there is just more to consider. 

Disclaimer – I am not a Pelvic Floor Physiotherapist however 6S Physio has got you covered with both a great Men’s Health Physiotherapist and Women’s Health Physiotherapist, if this scenario was a consideration in your presentation and bares similarities to your current condition.