Tarsal Tunnel Syndrome.
What is tarsal tunnel syndrome?
Tarsal tunnel syndrome (TTS) is a nerve entrapment condition in which the tibial nerve — or one of its branches — is compressed as it passes through the tarsal tunnel, a narrow fibro-osseous channel on the inner side of the ankle just behind and below the medial malleolus. The tarsal tunnel is bounded by the ankle bones on one side and the flexor retinaculum (a thick fibrous band) on the other, and contains the tibial nerve alongside the posterior tibial tendon, flexor digitorum longus tendon, and blood vessels.
When the contents of this tunnel are compressed or the space is reduced, the tibial nerve becomes irritated, producing pain, burning, tingling and numbness along the sole of the foot and into the toes. Tarsal tunnel syndrome is sometimes called the foot equivalent of carpal tunnel syndrome — the underlying mechanism is essentially the same, though the involved nerve and anatomical location differ.
What causes tarsal tunnel syndrome?
Any factor that reduces the space within the tarsal tunnel or increases the tension on the tibial nerve can cause TTS. The most common causes include space-occupying lesions within the tunnel — ganglia (fluid-filled cysts), lipomas, varicose veins, or accessory muscles that reduce the available space for the nerve. Flat foot deformity — particularly posterior tibial tendon dysfunction — is a significant contributor, as valgus heel alignment increases tension on the tibial nerve as it curves around the medial malleolus.
Previous ankle injuries including fractures and ankle sprains can produce scarring or altered bony anatomy that compresses the tunnel contents. Inflammatory conditions including rheumatoid arthritis and tenosynovitis of the adjacent tendons can increase tunnel pressure through swelling of the tendon sheaths.
Systemic conditions that affect nerve health — diabetes, hypothyroidism, and other causes of peripheral neuropathy — increase susceptibility to nerve compression at anatomical tunnels and should be considered in the assessment of TTS.
What are the symptoms?
The characteristic symptoms are burning pain, tingling, numbness or an electric shock sensation along the inner ankle and sole of the foot, corresponding to the distribution of the tibial nerve and its branches. Symptoms are typically provoked by prolonged standing and walking, and may improve with rest and elevation. Night pain is common and can be severe enough to disturb sleep.
The distribution of symptoms varies depending on which branch of the tibial nerve is most affected. The medial plantar nerve supplies the medial two-thirds of the sole and the first three and a half toes. The lateral plantar nerve supplies the lateral sole and outer toes. The medial calcaneal branch supplies the heel. Identifying which distribution is affected helps localise the compression site within or around the tarsal tunnel.
A clinically important distinction is between true tarsal tunnel syndrome and the more common plantar fasciitis or heel pain syndrome — both can produce heel and foot pain, but the neurological symptoms (tingling, numbness, burning) are characteristic of nerve involvement and distinguish TTS from purely mechanical foot pain.
How is it diagnosed?
Tinel's sign at the tarsal tunnel — tapping over the tibial nerve just behind and below the medial malleolus — reproduces tingling or electric sensations in the foot distribution of the nerve and is the most characteristic clinical test. Dorsiflexion-eversion of the foot, which tightens the flexor retinaculum and compresses the tunnel contents, may also reproduce symptoms.
Nerve conduction studies provide electrophysiological confirmation of tibial nerve dysfunction and help grade the severity of entrapment. MRI or ultrasound of the tarsal tunnel identifies space-occupying lesions, defines the anatomy, and rules out other causes of inner ankle and foot pain. Weight-bearing foot X-rays assess the degree of valgus deformity that may be contributing.
How can physiotherapy help?
Physiotherapy is effective for many cases of tarsal tunnel syndrome, particularly those where biomechanical contributors — flat foot deformity, altered lower limb mechanics — are the primary driver of nerve compression.
Foot and ankle orthotic management is often central to conservative treatment. Correcting valgus heel alignment with a medially wedged orthosis or custom foot orthosis reduces the tension and compression on the tibial nerve as it courses around the medial malleolus. Your physiotherapist will assess your foot biomechanics and advise on appropriate orthotic options — off-the-shelf or custom — depending on the degree of deformity and the severity of symptoms.
Neural mobilisation — gentle tibial nerve gliding exercises that promote nerve mobility through the tarsal tunnel — reduces mechanosensitivity and can significantly improve symptoms, particularly when the nerve has become sensitised and irritable from chronic low-grade compression. These techniques are similar in principle to the neural mobilisation used for carpal tunnel syndrome and are a core component of conservative TTS management.
Intrinsic foot and calf strengthening addresses the dynamic support deficits that contribute to arch collapse and valgus loading of the ankle. Real time ultrasound can assist in retraining deep foot and calf muscle activation where pain and altered mechanics have disrupted normal neuromuscular patterns.
Where a space-occupying lesion such as a ganglion or varicose vein is identified on imaging as the primary cause of compression, physiotherapy can manage symptoms but will not resolve the underlying compression — referral for aspiration, injection or surgical excision of the lesion is appropriate in these cases. Similarly, surgical tarsal tunnel release may be considered for cases that have not responded to an adequate trial of conservative management.
Our physiotherapists Bethany Kippen and Emma Cameron both have experience in foot and ankle nerve conditions and are members of the Australian Physiotherapy Association. Yulia Khasyanova's specialist background in complex nerve conditions is also relevant for patients with more complex or treatment-resistant presentations.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
Tarsal tunnel syndrome (TTS) is a nerve entrapment condition in which the tibial nerve — or one of its branches — is compressed as it passes through the tarsal tunnel, a narrow fibro-osseous channel on the inner side of the ankle just behind and below the medial malleolus. The tarsal tunnel is bounded by the ankle bones on one side and the flexor retinaculum (a thick fibrous band) on the other, and contains the tibial nerve alongside the posterior tibial tendon, flexor digitorum longus tendon, and blood vessels.
When the contents of this tunnel are compressed or the space is reduced, the tibial nerve becomes irritated, producing pain, burning, tingling and numbness along the sole of the foot and into the toes. Tarsal tunnel syndrome is sometimes called the foot equivalent of carpal tunnel syndrome — the underlying mechanism is essentially the same, though the involved nerve and anatomical location differ.
What causes tarsal tunnel syndrome?
Any factor that reduces the space within the tarsal tunnel or increases the tension on the tibial nerve can cause TTS. The most common causes include space-occupying lesions within the tunnel — ganglia (fluid-filled cysts), lipomas, varicose veins, or accessory muscles that reduce the available space for the nerve. Flat foot deformity — particularly posterior tibial tendon dysfunction — is a significant contributor, as valgus heel alignment increases tension on the tibial nerve as it curves around the medial malleolus.
Previous ankle injuries including fractures and ankle sprains can produce scarring or altered bony anatomy that compresses the tunnel contents. Inflammatory conditions including rheumatoid arthritis and tenosynovitis of the adjacent tendons can increase tunnel pressure through swelling of the tendon sheaths.
Systemic conditions that affect nerve health — diabetes, hypothyroidism, and other causes of peripheral neuropathy — increase susceptibility to nerve compression at anatomical tunnels and should be considered in the assessment of TTS.
What are the symptoms?
The characteristic symptoms are burning pain, tingling, numbness or an electric shock sensation along the inner ankle and sole of the foot, corresponding to the distribution of the tibial nerve and its branches. Symptoms are typically provoked by prolonged standing and walking, and may improve with rest and elevation. Night pain is common and can be severe enough to disturb sleep.
The distribution of symptoms varies depending on which branch of the tibial nerve is most affected. The medial plantar nerve supplies the medial two-thirds of the sole and the first three and a half toes. The lateral plantar nerve supplies the lateral sole and outer toes. The medial calcaneal branch supplies the heel. Identifying which distribution is affected helps localise the compression site within or around the tarsal tunnel.
A clinically important distinction is between true tarsal tunnel syndrome and the more common plantar fasciitis or heel pain syndrome — both can produce heel and foot pain, but the neurological symptoms (tingling, numbness, burning) are characteristic of nerve involvement and distinguish TTS from purely mechanical foot pain.
How is it diagnosed?
Tinel's sign at the tarsal tunnel — tapping over the tibial nerve just behind and below the medial malleolus — reproduces tingling or electric sensations in the foot distribution of the nerve and is the most characteristic clinical test. Dorsiflexion-eversion of the foot, which tightens the flexor retinaculum and compresses the tunnel contents, may also reproduce symptoms.
Nerve conduction studies provide electrophysiological confirmation of tibial nerve dysfunction and help grade the severity of entrapment. MRI or ultrasound of the tarsal tunnel identifies space-occupying lesions, defines the anatomy, and rules out other causes of inner ankle and foot pain. Weight-bearing foot X-rays assess the degree of valgus deformity that may be contributing.
How can physiotherapy help?
Physiotherapy is effective for many cases of tarsal tunnel syndrome, particularly those where biomechanical contributors — flat foot deformity, altered lower limb mechanics — are the primary driver of nerve compression.
Foot and ankle orthotic management is often central to conservative treatment. Correcting valgus heel alignment with a medially wedged orthosis or custom foot orthosis reduces the tension and compression on the tibial nerve as it courses around the medial malleolus. Your physiotherapist will assess your foot biomechanics and advise on appropriate orthotic options — off-the-shelf or custom — depending on the degree of deformity and the severity of symptoms.
Neural mobilisation — gentle tibial nerve gliding exercises that promote nerve mobility through the tarsal tunnel — reduces mechanosensitivity and can significantly improve symptoms, particularly when the nerve has become sensitised and irritable from chronic low-grade compression. These techniques are similar in principle to the neural mobilisation used for carpal tunnel syndrome and are a core component of conservative TTS management.
Intrinsic foot and calf strengthening addresses the dynamic support deficits that contribute to arch collapse and valgus loading of the ankle. Real time ultrasound can assist in retraining deep foot and calf muscle activation where pain and altered mechanics have disrupted normal neuromuscular patterns.
Where a space-occupying lesion such as a ganglion or varicose vein is identified on imaging as the primary cause of compression, physiotherapy can manage symptoms but will not resolve the underlying compression — referral for aspiration, injection or surgical excision of the lesion is appropriate in these cases. Similarly, surgical tarsal tunnel release may be considered for cases that have not responded to an adequate trial of conservative management.
Our physiotherapists Bethany Kippen and Emma Cameron both have experience in foot and ankle nerve conditions and are members of the Australian Physiotherapy Association. Yulia Khasyanova's specialist background in complex nerve conditions is also relevant for patients with more complex or treatment-resistant presentations.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
