I bought this great model of a foot recently – it’s a lot of fun to play around with and get a better feel / understanding of how the bones in the feet move and the knock on impact this has on the muscles / tendons that are attached. One of the areas I’ve been looking at more closely (as it’s something that I’ve historically had a problem with, thankfully not at the moment) is the relationship with how the foot moves and how this impacts on the achilles.
Our feet play a huge role in how our achilles works. Can our feet pronate – act as a mobile adaptor and spread, lowering each of the three arches, open the joints on the inside & rear of the foot whilst closing the joints on the outside / top of the foot. All with 3 points of contact, under heel, first metatarsal / 5th metatarsal. Loading all of the supinatory muscles of the foot by lengthening them ready to contract to pull the foot into a supination. Can you feet then properly supinate, turning into a rigid lever, arches raising, joints opening in the top & outside of the foot whilst closing on the base and inside of the foot. Can the foot do this with 3 points of contact on the ground? Are the mechanics in place to really allow the achilles to load / unload effectively and in a fashion that won’t lead to overload.
Looking at above the achilles crosses two joints – the two blue dotted lines in the drawing above, as it’s attached to the heel (or calcaneous) and runs across the talus bone into the soleus & gastrocenemius calf muscles above, which run down the back of the tibia / fibula leg bones so crossing the ankle.
So in simple terms the achilles will change it’s length if these joints open or close:
- At the ankle joint, if the knee comes forward (flexing) – or foot points up (dorsiflexing) the joint opens at the back, putting length in the achilles. When the opposite happens, knee straightens or goes back (extends) or foot points down (plantar flexes) the joint closes on the back shortening the achilles
- At the subtalar joint (talus and calaneous) the calcaneous can roll forwards, and in which opens the joint at the talus, lengthening the achilles attachment. When our foot shortens into a rigid lever and supinates. Alternatively the calcaneous can roll back and up, which closes the joint with the talus and so shortens the achilles attachment – what we look for when our foot lengthens and pronates.
What it seems is the achilles needs is a helpful trade off between the different movements to allow it to unload / load. So above as you have your knee bent, with your foot loading it will also look at pronating (if it can) so the joint at the ankle puts length in, whilst the subtalar joint is closing helping give slack. The opposite then happens when the knee straightens, leg extends and foot looks to supinate the joint at the ankle begins to close, shortening the achilles, whilst the heel rolling forwards opens the subtalar joint putting length in. The trade off again.
So where can the problems happen? Well if the foot is immobile and not really responding, then when the knee bends / straightens there is no trade off with the heel rolling forwards or backwards. Maybe a foot is stuck in a pronated shape, preventing any length from being put into the base of the calcaneous and limiting the range of motion that it had to lengthen / contract. Where else is going to take on board the extra load? What begins to do the job of the achilles the achilles is no longer able to effectively do?
Alternatively what if a foot is stuck in a more rigid supinatory position, with the heel rolled forwards, the achilles long at the attachment into the heel. Every step that the knee is bent the achilles is being pulled long and the achilles is never given a true opportunity to off load, via the rolling back motion of pronation. Eventually the achilles will give up and complain that it just needs a rest – and when this happens it’s pretty clear as the discomfort makes running pretty unbearable.
One of the compensatory patterns that can happen (and this something I was really prone to) is the foot cannot pronate. So when you land and load the ankle just dives into the inside of the foot, rather than the heel rolling forwards and also everting – or in the direction below:
So rather than this nice gliding, rolling movement, which sees the heel roll inwards, you get a far more aggressive opening at the joint above as this joint is pulled open by the ankle diving in – putting the achilles under great length & load at a time when the load would be far better served being distributed across both joints. Equally to then get the ankle complex upright, rather than the heel then reversing it’s direction, and inverting or rolling back the achilles has to shorten to pull the ankle back into position (or as likely the calf muscles or other muscles on the inside of the leg) overworking them until the break. The longer / faster you run the more likely or painful this compensation can become. So you then can have runners with that uncomfortable inside (medial) lower leg pain as without the ability to properly move their heel, they aren’t able to properly pronate / supinate and so overload the achilles / calf complex.
All of above is without considering the rotational aspect to the achilles & foot. When we pronate we internally rotate the rearfoot, when we supinate we externally rotate the foot. This in turn puts torque / force into the achilles. The greater the ability to rotate the greater the ability to manage that torque and force.
I was a great case in point. I had too much movement in my ankle forwards / backwards, but really poor rotational movement internally / externally. This in turn meaning my achilles wasn’t getting the chance to offload properly. I was far too internally rotated, making it hard for my heel to roll and both my feet to properly pronate / supinate. Rather they acted as paddles, dumping my ankles inside and leaving my achilles long. They would break down, I’d strengthen my calves – as that is what I thought the problem was, the achilles would go again. It wasn’t until I begun to focus on how my feet mechanics worked that I was really able to change the relationship with the achilles – and in turn my feet changing were linked to other parts of my body (and this thanks a lot to all of the work I did with Dom Koch). BUT the point here is that without building a better understanding of the foot I wouldn’t have looked at how to resolve a long term painful issue in a more effective fashion. Focusing on joint mechanics as opposed to purely muscle strengthening.
So if your achilles are problematic – they are working too hard. Ask yourself why and a good place to start is at the feet. How are your feet moving, what are they doing, what aren’t they doing. Can they actually pronate and supinate or do they just roll around like paddles not changing shape? What do your feet tell you? Then you can begin to think about why and how to change the joint mechanics that they are stuck in.
