Recently I posted this video about ankle stability, foot arch strength and how they both can contribute towards knee cave in various movements such as the squat, lunge and any other movement where your foot is in contact with the ground.
Below is the flow chart I use in my head when watching someone move who has valgus collapse or knee cave during a particular movement.
In recent years I've seen many people gravitating towards poorly functioning glutes or weak glutes being the reason why knee cave happens in a particular movement like a squat.
I think that the glutes are hugely important and need to be strong in order for people to perform well but I feel the ankles are a massively overlooked body-part (unless you are talking about squat depth where they are the go-to area when looking for a quick solution.)
What I never want to see is this absolutism when something happens with a movement it MUST be a certain thing that is causing it, many used this absolutism when considering the glutes and have completely forgotten about the ankles.
With knee cave, it's often a combination of many factors which is why coaches must get infinitely frustrated when the endless band walks they make their clients do achieve absolutely nothing when the person performs the movement they are struggling with.
The common solution to deal with knee cave is to perform a kind of exercise called RNT or reactive neuromuscular therapy. Which makes you sound very smart and like it must be scientific and correct.
Essentially from what I have seen of RNT it comprises of tying a resistance band to a post, putting the other into the band and standing far enough away from it that the band wants to pull the offending appendage in the direction it isn't supposed to go, thereby strengthening the muscles that keep the knee out.
Does it work?
Do I give things like that to my clients?
Yes, but only when we've done a full exploration to discover where we think the problem lies.
As you can see in the picture above the client has a perfect ankle position. If this is the case during an athletes movement then RNT is a great shout.
However more often than not it's something a little closer to the ground that is the route of the issue. When the foot arch isn't strong enough or the ankle isn't stable enough you are on shakey ground with every step you take.
Take your shoes off and stand on one-leg.
Look down at your feet.
Has the arch collapsed and your knee caved in?
If the answer is yes and your knee caves in during any other movement then the ankle and foot arch should be the first thing you address.
Once you can stand on one leg without the ankle collapsing you can learn to squat without your ankles collapsing inwards.
With some people just being aware of the foot arch being important is enough for them to make sufficient changes in their movement to correct the issue. With others they will need specific warm up exercises that focus on 'rooting' the feet to the floor and encourage a strong arch.
My coach has me doing a split-squat and a single leg deadlift so I remember to root my feet. It works well for me.
Others need to do specific paused work where they will pause in the position where their knee caves in and work on correcting the movement from that difficult position.
Once the ankle and foot are sorted you can then work further up the chain (while strengthening the glutes throughout) and sort a lot of movement problems as well as preventing certain overuse injuries like plantar fasciitis.
The video above will show you how to get the feet in a stronger position to build the foundation of a movement.
The thing in contact with the floor (your foot) will drive where the knee can go.
Once you have a strong foot and ankle that is mobile enough to move through a full range of motion you can rule out the ankle and foot as the cause of knee cave in the squat and lunge patterns.
Dealing with things further up the chain will be the subject of later articles I am sure.
If you get one thing out of today's article it should be that you should work on the roots. The feet and the ankles. Once they are positioned well many movements will improve a great deal and it will be easier to strengthen your glutes through big exercises like squats.
I forgot to mention wearing decent shoes too. If your shoes are big spongy monstrosities then get rid of them when you are in the gym. They are ruining your gains! (and strength.)
By Chris K
Chris is a Personal Trainer, Strength Coach, Writer and man of small stature and reader of The Discworld Series with a decade in the industry. He trains everyone from beginners to high level athletes. His favourite clients are people getting into the gym for the first time because they can make the biggest changes in their life.
You can reach me through the email address Chris@kershawstrength.com
My Instagram is Chris_Kershaw_Strength.
Thank you for reading!