Tarsal Tunnel Syndrome is one of many conditions that can cause pain or funny sensations on the inner part of your ankle as well as under your foot. In this article, I'll explain what it feels like, how you can test for it, and what treatments may be useful.
In this article:
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What it is
Your Tarsal Tunnel is located on the inside of your ankle. The tunnel is formed between the bones on the inner part of the ankle and a thick fibrous band (the flexor retinaculum) that runs from the medial malleolus to your heel bone.
The Tarsal Tunnel contains the posterior tibial tendon, the flexor digitorum longus tendon, the posterior tibial artery and veins, the posterior tibial nerve and the flexor hallucis tendon. The posterior tibial nerve runs behind and below the medial malleolus and divides into two smaller nerves, the medial and lateral plantar nerves.
Tarsal Tunnel Syndrome develops when the pressure inside the tunnel increases, compressing the posterior tibial nerve or any of its smaller branches.
What can cause it?
Tarsal Tunnel Syndrome can be caused by anything that decreases the space and therefore increases the pressure inside the tarsal tunnel. Some of the most common causes include:
Changes in the foot anatomy e.g. when the foot arch flattens.
Excessive pronation of the foot
Thickening of retinaculum or the tendons that run inside the tunnel e.g. thickening of the tibialis posterior tendon when you have Tib Post Tendinopathy
Cysts or growths inside the tunnel
What it feels like
We all have slight differences in where the tibial nerve runs and also at what level it splits into the medial and lateral plantar nerves. As a result you may find that where you feel your pain or symptoms is in a different area than other people with this condition.
You can experience pain, throbbing, numbness, tingling or funny sensations on the inside of the ankle or underneath your foot, but it can also shoot up into your calf. The pain from Tarsal Tunnel Syndrome can easily be misdiagnosed as plantar fasciitis, because it can cause a similar pain under the heel.
Nerve root irritation involving the L4, L5 or S1 nerve roots can also refer pain into that area. You can even have a “double crush” injury where the nerve can be stuck higher up the leg or in the lower back, causing it to pull extra tight around the ankle when you walk. This is why it is useful to consult a clinician who can listen to all your symptoms and test everything from your lower back down to your ankle.
How do you test for it?
Important! None of these tests are 100% accurate. This means that the test may sometimes produce pain even when you don’t have Tarsal Tunnel Syndrome and other times all the test may be pain free despite your nerve being compressed. The tests have to be combined with a full examination of the rest of your leg and lower back.
Tinel’s test: You tap over the nerve in the area that you think it may be compressed. If it produces funny sensations or pins and needles, the test is positive and you may have Tarsal Tunnel Syndrome.
Combined Dorsiflexion & Eversion test: You bend the foot up into dorsiflexion and at the same time turn it out into eversion. This position puts extra strain on the posterior tibial nerve.
Combined Plantar flexion & Inversion: You point the toes down and at the same time turn the foot in into inversion. This position compresses the tarsal tunnel.
Treatment for Tarsal Tunnel Syndrome
Treatment for Tarsal Tunnel Syndrome has to be specifically designed for you. It has to address the reason why YOUR nerve is being compressed. Is it your foot’s position or thickened tendons or maybe an activity that you’re doing on a regular basis that is causing your problem?
Conservative treatment consisting of soft tissue massage, dry needling and stretches can work well for some. Just be careful – calf stretches can sometimes make the pain feel worse. Orthotics or supportive insoles can also be useful to help reduce over-pronation. Strengthening the muscles that support the foot and leg may help for others.
In cases that does not respond to conservative treatment, corticosteroid injections and immobilising the foot for a period in a boot may work. Surgery, where they release the nerve, is also an option and can give good results. However, that too doesn’t work for everyone.
Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.
About the Author
Maryke Louw is a chartered physiotherapist with more than 15 years' experience and a Masters Degree in Sports Injury Management. Follow her on LinkedIn, ResearchGate, Facebook, Twitter or Instagram.
