Tarsal tunnel syndrome occurs when the posterior tibial nerve, which runs along the inside of the ankle and foot, becomes compressed and damaged, causing inflammation.
The condition, also known as TTS, is usually caused by continual overuse of the foot and ankle, such as occurs with strenuous or prolonged walking, running, standing, or exercising.
But TTS can also occur suddenly after traumatic injury, or spontaneously, for no clear reason.
A doctor should always assess and treat symptoms of TTS early.
The first line of treatment for TTS is RICE, which stands for rest, ice, compression, and elevation.
Over-the-counter non-steroidal anti-inflammatory medications, or NSAIDs, such as acetaminophen or ibuprofen, can also help make symptoms more manageable.
For more severe or chronic cases, more aggressive treatment options exist, such as corrective devices, therapies, and in some cases, surgery.
Common ways to manage and treat TTS include:
- Rest: The easiest and most immediate way to reduce inflammation anywhere in the body is to stop using and putting pressure on the affected area. How long an individual should rest the foot depends mostly on the severity of symptoms. For minor cases, rest may mean replacing running with swimming. For more severe cases, resting the nerve may require completely refraining from exercise and activity.
- Ice: An ice pack covered with a cloth or towel can be applied to the inside of the ankle and foot for 20-minute sessions to reduce inflammation. It is best to have the foot elevated during this time. Icing sessions can be repeated several times daily, as long as breaks of at least 40 minutes are taken.
- Compression and elevation: Compressing the foot, and keeping it raised above the heart, helps reduce blood flow to the foot, and so reduces inflammation. Try wrapping the foot with an ACE wrap, and resting it on a pillow while sitting and sleeping.
- Over-the-counter pain and anti-inflammatory medications: These can include ibuprofen and acetaminophen.
- Full immobilization: For severe cases, especially those involving physical damage to the nerve, a cast may be necessary to restrict movement completely, allowing the nerve, joint, and surrounding tissues a chance to heal.
- Injection therapy: For very painful or disabling symptoms, anti-inflammatory medication, such as corticosteroids and local anesthetics, may be directly injected into the nerve.
- Orthopedic devices and corrective shoes: Podiatrists can make specialized shoes, and inserts that help support the arch and limit motions that can further irritate the inflamed nerve and surrounding tissues. Shoes also exist to help prevent pronation or inward rolling of the foot.
- Reducing foot pressure: In some cases, wearing looser or larger fitting footwear and socks may help reduce tightness around the foot.
- Physical therapy: Physical therapy exercises can often help reduce symptoms of TTS long-term, by slowly stretching and strengthening the connective tissues, mobilizing the tibial nerve and opening the surrounding joint space to reduce compression.
Other types of physical therapy used for TTS include:
Ultimately, surgery may be performed for very severe or chronic cases of TTS that do not respond to any other form of medical or physical therapy.
As symptoms become less painful or easily irritated, strengthening exercises should be done to help prevent problems, including pronation or rolling of the foot, which can worsen symptoms.
Common exercises recommended for the treatment of TTS include:
Ankle pumps, circles, and eversion or inversion
- Sitting down with the legs extended, slowly and gently bend the foot at the ankles downward towards the ground, and then upwards towards the body, as much as possible, without pain. Repeat several times.
- Slowly and gently roll the ankles through their circular range of motion as aggressively, as is comfortable, several times.
- Slowly turn the ankles inward and outward, creating a windshield wiper motion, several times, as far as is comfortable.
- Repeat all three exercises several times daily.
- Standing straight, slowly raise or flex the toes upward, as far as possible, without pain.
- Slowly lower the toes and gently raise the heels, putting gradual pressure on the ball of the foot.
- Repeat this exercise 10 times and perform several times daily.
Pencil toe lifts
- Sitting down with the legs fully extended, place a pencil or pen on the floor directly below the toes and attempt to pick it up using only the toes.
- Once the pencil is fully grasped, hold for 10 to 15 seconds.
- Relax the toes.
- Repeat 10 times and perform several times daily.
- Standing straight slowly raise one leg and rest the sole of the raised foot on the inner calf of the other foot.
- Hold for at least 10 to 15 seconds or, as long as is comfortable, without overstretching the inner ankle and foot. If too wobbly, stop by lowering the foot and restarting the exercise.
- For a more intense version of this exercise, gradually lift the raised leg further in the air, away from the body.
Plantar fascia stretch
- Sitting down with the legs extended, as far as comfortable, reach out and grasp the big toe and top of the sole, then gently pull backward. This can also be done using a stretching band, dishtowel, or sock.
- Stretch the foot backward until a stretch that runs from the sole to the ball of the foot is felt.
- Hold for 30 seconds before slowly releasing the foot.
- Repeat the stretch at least three to five times, three times daily for several weeks, even after initial symptoms have greatly improved to reduce the chances of them returning.
- The plantar fascia ligament can also be stretched by rolling out the arch, sole, and heel in a gentle downward motion on something round, such as a soup can, therapy ball, tennis ball, or rolling pin.
- Standing a small distance away from a wall, step one foot forward, closer to the wall, and lean in, pressing the hands into the wall while keeping the back leg straight. This position should look somewhat similar to an assisted lunge.
- Widen or deepen, the stretch as feels comfortable or produces a notice, pain-free stretch along the full-length of the back of the calf.
- Start by holding the stretch for 10 to 15 seconds, gradually increasing holding time to reach 45-second intervals.
- Repeat the stretch three to five times consecutively, three times daily for several weeks.
- For a more intense stretch, try standing on a step with the foot halfway hanging off the edge, and then gently push the heel downwards. Hold for as long as feels comfortable, up to 10 times daily.
Soleus muscle stretch
- Repeat the steps of the gastrocnemius stretch, except with the back leg being stretched bent at the knee.
- To increase the stretch, place something under the front or ball of the foot, or prop the ball of the foot up on the wall.
A doctor will typically diagnose and assess TTS by performing a physical exam of the entire foot and lower leg area and asking questions about symptoms.
Diagnostic tests used to confirm and evaluate TTS include:
- nerve conduction velocity (EMG/NCV)
- magnetic resonance imaging or MRI
Though anyone can develop TTS at any age, some factors greatly increase the risk of developing the condition.
Common risk factors for TTS include:
- chronic overpronation or rolling inward of the foot when walking
- flat feet or fallen arches
- rheumatoid arthritis
- diabetes and other metabolic conditions
- ankle or foot injury
- jobs that require standing or walking for a long time, such as retail, teaching, mechanical, manufacturing, and surgical jobs
- poorly-fitting shoes that allow the foot to pronate inward or do not support the arch and ankle
- nerve disease
- cysts, tumors, or small masses in the foot and ankle area
- proliferative synovitis or inflammation of the synovial membrane
- varicose veins or inflamed, enlarged veins
- foot deformities
- reflex sympathetic dystrophy
- peripheral neuropathy conditions
- generalized leg edema or swelling, especially related to pregnancy
- being overweight
TTS tends to cause pain on the inside of the ankle and bottom of the feet, though it can also impact the toes and lower legs. TTS is similar to carpal tunnel syndrome, involving a nerve being squeezed in a narrow, confined, tunnel-like joint space.
Common symptoms of TTS include:
- searing, shooting pain
- the sensation of electric shocks
- weakened ability to flex, bend, and fan out the toes
- loss of sensation in the toes and bottom and sides of the feet
Minor cases of TTS can improve significantly with 48 hours of RICE and over-the-counter medications. But left untreated, chronic TTS may become disabling and cause permanent nerve damage.
A person should consult with a doctor anytime TTS symptoms occur. If caught early enough, a wide range of therapies, medications, and corrective devices exist to help treat most TTS symptoms.