Tarsal Tunnel Syndrome

Note: Tarsal tunnel syndrome refers to symptoms in the foot. Carpal Tunnel Syndrome refers to symptoms in the hand and fingers.

What is Tarsal Tunnel Syndrome?

The “tarsal tunnel” is the space formed between the medial malleolus (inside ankle bone) and the foot flexor retinaculum, a band of tough fascia designed to bind down tendons where they suddenly change direction. Tarsal Tunnel Syndrome (TTS) is considered to be a nerve compression pathology in the foot. Specific cause is required to determine diagnosis, and several steps are taken to make the determination.

Tibial nerve thru tarsal tunnel

(click to enlarge)

In the vast number of cases, TTS refers to a compressed posterior tibial nerve below the inside ankle bone. However, branches of the posterior tibial nerve distal to the ankle bone (the calcaneal nerve, and medial and lateral plantar nerves) may mimic symptoms from compression by other structures close to and below the ankle bone.

Other minor considerations for tarsal tunnel syndrome are vascular and musculotendonous compression within the tarsal tunnel.

Tarsal tunnel syndrome commonly appears in both feet simultaneously.

Symptoms of Tarsal Tunnel Syndrome

TTS is characterized by a burning or tingling sensation in the bottom of the foot, usually in the bottom of the mid-foot or further back, near the bottom of the calcaneus (heel bone), and all toes except the little toe. Pain may be described as an electric shock or shooting pain. Pressure or pain may also be felt below the inside ankle bone (medial malleolus) at the point of compression.

Several other symptoms may present with this syndrome:

  • Pain usually radiates downward, but may radiate up the leg
  • Hot and cold sensations in affected feet
  • Foot or ankle swelling

Additionally:

  • pain may change with foot and ankle position
  • pain usually increases with longer periods of standing and use of foot and ankle (such as driving)
  • pain may decrease with rest and/or elevation

Causes of Tarsal Tunnel Syndrome

It has been found that approximately 1/3 of TTS cause is idiopathic in nature, meaning unknown. Meanwhile, the symptoms define the cause in many if not most cases. Doctors look for where and how compression takes place rather than why it does. As a result, the invasive remedy is often determined by the symptoms.

Some causes of TTS are:

  • natural formation of the tunnel and structures
  • edema in the area of the tarsal tunnel
  • swelling or scarring in the nerve
  • irritation by movement or inflammation of other structures running through the tarsal tunnel
  • collapse of the inside arch of the foot (flat or pronated foot)
  • injury, such as ankle break or sprain
  • bone spurring
  • arthritis (often rheumatoid)
  • cyst or tumor, including tumor of the nerve ganglia
  • varicose veins

Sometimes, tarsal tunnel syndrome may be misdiagnosed, most often as plantar fasciitis. TTS may actually be the misdiagnosis for other types of neuropathy or polyneuropathy, nerve root compression at L5/S1, and neuromas.

Overview of Tarsal Tunnel Anatomy

The tarsal tunnel differs from the carpal tunnel by the fact that the tarsal tunnel consists of several “tunnels” or indentations in the heel bones of the foot compared to a single tunnel in the wrist. The tarsal tunnel is formed only on the medial side of the ankle, not the lateral side. The top of the tarsal tunnel is formed by a strong, fibrous, ligament called the flexor retinaculum. The flexor retinaculum connects to the medial malleolus at the top and runs diagonally down and back to the calcaneous. The ligamentous tissue binds down all the structures which pass around the bottom of the ankle bone:

  • posterior tibialis tendon
  • flexor digitorum longus tendon
  • flexor hallucis longus tendon
  • posterior tibial nerve
  • posterior tibial artery

Other inflammatory structures in the tunnel are the tendon sheaths of the above-noted muscles. When aggravated, these tendon sheaths may become inflamed, causing compression of the tendon or surrounding structures.

In addition, there are two bursae that live in the area of the tarsal tunnel. These are the retrocalcaneal bursa and the subcutaneous bursa of the medial malleolus.

 Manchester-Bedford Myoskeletal View of Tarsal Tunnel Syndrome

Once diagnosed by a physician and contraindications do not include massage therapy, a patient presenting with tarsal tunnel syndrome may be a candidate for conservative treatment in our clinic. Research shows non-invasive treatment can be successful in many cases.

We would first assess the patient from a myoskeletal standpoint. That is, assess the alignment of the skeletal structure of the body, lumbosacral region, lower extremities, and feet. A further assessment of muscular facilitation and inhibition will follow the skeletal exam. The purpose of these two exams is to determine the functional component leading up to TTS symptoms. A movement screen will also take place during the first and second assessments.

Myoskeletal and remedial massage would then be combined to make corrections to bony realignment, muscle firing order, and determining further treatment plan for manual therapy, including joint mobilization, muscle strengthening, and referral, if necessary, to other integrative forms of bodywork.

If the patient is under the care of a physician for tarsal tunnel syndrome, we would inform the physician of our assessment findings, treatment plan, and progress.