I have been struggling with plantar fasciitis for months. I thought that it was hanging around because I have been neglecting to treat it. As a physical therapist, there is really no excuse for letting this continue and get worse. So I started treating it. I have done everything that one is supposed to do for plantar fasciitis. I have even been treated by colleagues. It is not helping. One my colleagues noted significant weakness in my big toe. I noticed that when I use soft tissue mobilization to release my posterior tibialis muscle and tendon, the pain decreases. Neither of these symptoms are consistent with plantar fasciitis. Maybe this isn’t plantar fasciitis. Could it be the much more rare tarsal tunnel syndrome? I have started doing tarsal tunnel syndrome exercises to see if they work. Read on to learn more about this condition.
What is tarsal tunnel syndrome?
Tarsal tunnel syndrome is a nerve entrapment of the tibial nerve. It is analogous to carpal tunnel syndrome in the hand but is not as common. There is a tunnel, of sorts, where the tibial nerve, posterior tibial artery and vein, and several tendons go through. The tunnel is made up of the medial malleolus (the boney bump on the inside of the ankle), the talus (the bone right above the heel bone), the calcaneous (the heel bone) and flexor retinaculum. The flexor retinaculum makes up the roof of the tunnel and is a dense band of connective tissue that holds the tendons of the tarsal tunnel in place. The tunnel is located just behind and slightly below the medial maleolus or the boney bump on the inside of the ankle.
Tendons connect muscle to bone. The tendons of posterior tibialis, flexor hallicus longus, and flexor digitorum longus muscles go through the tarsal tunnel. These muscles are located in the back of the lower leg under the calf muscle. Their tendons pass through the tunnel to connect them to various areas of the foot. These muscles flex the toes and also move the foot inward and down.
The tibial nerve is a branch of the sciatic nerve. The tibial nerve splits into other nerve branches as it passes through the tarsal tunnel. These branches of the nerve innervate many muscles in the foot and provide sensation to the bottom of the foot. Compression on the tibial nerve or it’s branches within this tunnel is what causes tarsal tunnel syndrome. See the video below for more explanation on the tarsal tunnel and the different branches of the tibial nerve.
What causes tarsal tunnel syndrome?
There are many causes of tarsal tunnel syndrome. Basically anything that can decrease the area of the tarsal tunnel and cause compression on the nerve can cause tarsal tunnel syndrome. This includes:
- Repetitive stress
- Running
- Excessive walking or standing
- Trauma – ankle sprain, fracture, or dislocation
- Obesity
- Growths
- Ganglion cysts – This is a fluid filled lump that can appear on or near a tendon.
- Bone spurs
- Varicose veins
- Masses
- Lipomas – This is a lump of fatty tissue that grows just under the skin.
- Tumors
- Systemic conditions
- Diabetes
- Arthritis
- Hypothyroidism
- Flat feet
- High arches
- Tendinopathy – Irritation of the tendons that go through the tunnel could cause compression.
- Tenosynivitis – Irritation of the sheaths that cover the tendon could cause compression.
- Post-surgical scarring
What are the symptoms of tarsal tunnel syndrome?
There are many symptoms of tarsal tunnel syndrome. These symptoms can be varied depending on which branches of the nerve are compressed and the extent of the compression.
- Burning, tingling, or numbness in the bottom of the foot
- Symptoms may worsen at night
- Pain increases with walking and standing
- Pain is worse after physical activity
- Pain is better with rest
- May have weakness in the foot
- Tenderness behind the medial maleolus (boney bump on inside of ankle)
- Pain with eversion and dorsiflexion – moving your foot out and up
How common is tarsal tunnel syndrome?
The real answer is no one really knows. It is often overlooked because it mimics many other conditions that are much more common, such as plantar fasciitis. It is thought to be predominately in adults and affects more women than men. It also tends to be more common in athletes or people who engage in long periods of standing or walking.
So do I have tarsal tunnel syndrome?
I have many of the symptoms including burning pain in the heel that increases with walking and standing. I also have some weakness in the foot especially at the big toe. However, I have no numbness and tingling. All the symptoms improve with rest. I have some risk factors. I am very active. My job is very physical and I run and practice yoga several times a week. I stand for long periods of time at work and at home. There is also some definite tendinopathy in my posterior tibialis and flexor hallucis longus. This could cause the compression in the tarsal tunnel and would also explain why treating these muscles improves my pain. So there is a reasonable chance that I do have tarsal tunnel syndrome.
What is my prognosis?
The prognosis depends on what is causing it. If I have it because of tendinopathy, my prognosis is pretty good because it should go away when I treat the tendinopathy. If the cause is from a systemic condition or a cyst in the area, then recovery could be much more difficult.
What should I do if I suspect tarsal tunnel syndrome.
- Physical therapist – This is obviously a complex condition so going to a healthcare professional would be required for an accurate diagnosis. A physical therapist can help figure out the underlying cause of the tarsal tunnel syndrome especially if it is musculoskeletal in nature. PTs can also determine areas that need stretching and strengthening. Your PT can help improve your symptoms with manual therapy, dry needling, gait analysis, taping, and a personalized home exercise program.
- Primary care physician – If the compression of the tibial nerve is coming from a systemic cause, growth, or mass, then seeing your PCP would be more appropriate. Your PCP can order imaging and run tests to determine the cause and treatment. Your PCP might refer you to a specialist.
What can I do?
- Relative rest – Stop the activity that causing discomfort. This is easier said than done. If running is irritating the foot, then switching to an activity that doesn’t cause pain, like swimming or biking. If you are having pain with standing for prolonged periods of time, try sitting and resting when possible. I stand a good portion of the time at work but I have made more of an effort to sit when there is an opportunity.
- Ice – Ice the area behind the medial malleolus where the tarsal tunnel is located. This can decrease inflammation and possible swelling in the tunnel. Ice with an ice pack for 15 to 20 minutes several times a day especially if the pain is interfering with daily activities. You can also ice the area of the foot that hurts.
- Stretching – Stretching the calf muscle and the plantar fascia can help improve walking mechanics and also decrease irritation at the ankle and foot. See the video below for calf and plantar fascia stretching.
- Nerve mobilization – Mobilizing the sciatic nerve can help free up the nerve if it is stuck in the tarsal tunnel. Below is a video of how to mobilize the nerve.
- Strengthening – Strengthening the areas of the foot and leg that are weak is important in improving foot biomechanics. It is also important to activate and strengthen the muscles of the foot that have been weakened by the nerve compression. Using a resistance band can add more difficulty and strength. Below is a video on strengthening the posterior tibialis, flexor hallicus longus, and the flexor digitorum longus.
- Shoe wear – Changing shoe wear or using orthotics to place the foot in a neutral position will help decrease the stress on the nerve. Most running stores will evaluate your foot type and suggest appropriate shoe wear and/or orthotics. Your PT can evaluate your foot and help determine appropriate shoe wear.
In review
- Tarsal tunnel syndrome is a compression of the tibial nerve or it’s branches in the tarsal tunnel.
- The tarsal tunnel is located behind and slightly below the medial maleolus (the bony bump on the inner ankle).
- There are many causes of tarsal tunnel syndrome.
- It’s symptoms include foot pain, numbness, and/or tingling. Pain will increase with walking and standing and decrease with rest.
- Tarsal tunnel syndrome is under diagnosed because it mimics other more common conditions like plantar fasciitis.
- If you suspect tarsal tunnel syndrome, see a medical professional.
- There are some things you can do that might help your pain.
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.physio-pedia.com/Tarsal_Tunnel_Syndrome
https://www.ncbi.nlm.nih.gov/books/NBK513273/
Update
So it turns out that I really did have tarsal tunnel syndrome. I wrote this post several months ago when I began treating myself for the condition. It will still occasionally flare up, but I am able to run several times a week and even walk around without shoes without pain during or afterwards. Also I know how to handle the flare ups which are progressively decreasing in frequency and intensity.