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While I’m on the topic of achilles tendonitis, I figured I would continue the conversation from last week to understand the causes of this issue. This way, we might find one overwhelming cause and be able to address it as a whole instead of just looking for daily relief. 

Tight/Restricted Shin Muscles

The first one I want to talk about is having tight or restricted tibialis anterior and/or peroneal muscles (large muscles on the outside of shin bone). I mentioned this one in my last post because it is something that most athletes would benefit from understanding, especially runners, hikers, and people going up and down hills a lot.

The first thing to understand is that the achilles tendon and the tibialis anterior share a reciprocal inhibition relationship. This means that one inhibits the other at any given time. When one is stretching, the other is contracting and vice versa.

So when you are running and your planted foot is about to push off, your achilles tendon is stretched and your tibialis anterior is contracted. After you push off, the roles will be switched. 

If you’re feeling like your achilles tendon can’t contract like it needs to when pushing you forward, it could be because the tibialis anterior is too tight to allow that movement to happen. You may be getting the pain signal on your achilles, but the actual restriction might be on the front of your leg with its opposing muscle. 

This is why someone who hikes a lot or runs a lot of hills should be wary. When you’re climbing uphill, your tibialis anterior is contracting a lot more than usual meaning that it will get tighter over time.

Climbing uphill when your tibialis anterior is already too tight is going to put a lot of strain on it because you are really relying on it to allow your achilles to contract hard so you can propel yourself uphill. 

Traditional Footwear

Going further into this, there’s a cause within a cause of achilles tendonitis, and it’s your shoes! Traditional footwear comes with a built-in toe spring and a super thick, inflexible sole.

This is horrible when we’re hiking or running because these features force our muscles into bad positions and they won’t allow them to make their proper functions.

The toe spring is the upward point in the toe box which causes our tibialis anterior to sit in a contracted (tight) state all the time. Your toes don’t have a natural upward arc like that when barefoot. To feel what I’m talking about, practice pulling your toes back toward you while barefoot and feel which muscles its activating. Hint: it’s the tibialis anterior contracting!

The thick, inflexible sole keeps our achilles from being able to fully make its propelling contraction that we need to move forward. You need a sole that is flexible to allow your foot to still make the natural movements it needs to make while running or going uphill.

This is why I switched to minimalist footwear. They come with no toe spring so your toes can be level with the rest of your foot and your tibialis anterior can relax as well. They also have a highly flexible rubber sole that will move with your foot, rather than dictating what your foot is allowed to do. 

Tight Calf Fascia

The next cause is a lot simpler than the first and needs much less explaining. Tight calf fascia (connective tissue), is something that plagues any person who is not actively taking care of it in my opinion.

Considering that fascia can get tight from not moving enough or not enough movement variation and it can get tight from a lot of intense movement without proper recovery, I would say literally anyone could benefit from releasing their calf fascia.

The gastrocnemius and soleus muscles in particular (two of the biggest calf muscles) should get released as the fascia surrounding them is most likely tight and pulling on the achilles, giving it that uncomfortable tugging feeling.

When that calf fascia is tight, it is limiting the blood flow that can reach the achilles tendon and if you are nursing any kind of achilles injury, a lack of blood flow reaching that area is bad news. This makes the affected muscle and fascia around it tight and brittle because it essentially is dehydrated.

Our muscles and fascia do need water but they also need optimal blood flow passing through them to maintain a healthy level of hydration. 

All the Lower Body Fascia is Tight

The third cause is similar to the second as it has the same type of solutions available but it would be a lot more work. Some of the telltale signs that all of your lower body fascia is tight is having inflammation in the plantar fascia and on your heel.

What many people start to develop is some thick, fibrous plantar fascia that feels hard to break down and in addition, a bony bump on their heel/bottom of the achilles that looks like a bunion. I have both of these by the way and it pains me just writing this!

You may even have plantar fasciitis and achilles tendonitis at the same time (me again) and this is almost a sure sign that your entire lower body’s fascia needs work because its restricting your feet and achilles.

When i say lower body, I mean starting with everything in and around the calves. The tibialis anterior and peroneal muscles like we talked about earlier, your gastrocnemius and soleus muscles, and any other spots that you find to be tender around your calves.

After checking those, look to your plantar fascia (bottom/arch of foot) and then even your hamstrings and quadricep muscles can play a role in these types of injuries. I, myself, need to start looking at those muscles because I have been feeling recurring pain from my old injury so I obviously haven’t fully solved it yet.

Make sure to test these areas one at a time so you can get feedback on what is making you feel better and what is not.

For example, my achilles has been feeling very tight lately so I first tried the tibialis anterior release technique that I wrote about in my last post. This release does enough to give me some relief before I play soccer so I’ve been using it for the last couple weeks and then I will probably move onto another technique soon.