Posterior Tibial Tendon Dysfunction (PTTD)
What is posterior tibial tendon dysfunction?
Posterior tibial tendon dysfunction (PTTD) — also called adult acquired flatfoot deformity — is a progressive condition in which the posterior tibial tendon, the primary active support of the medial longitudinal arch of the foot, degenerates and gradually fails. As the tendon loses its ability to function effectively, the arch collapses, the heel rolls into valgus (outward), and the forefoot abducts — producing the characteristic flatfoot deformity that gives the condition its alternative name.
The posterior tibial muscle originates in the deep posterior compartment of the lower leg and its tendon passes behind the medial malleolus (the inner ankle bump) before inserting into the navicular and surrounding tarsal bones. In a healthy foot it actively inverts the heel and supports the arch during the propulsive phase of walking. When it fails, every step places abnormal stress on the passive stabilising structures of the midfoot — the spring ligament, plantar fascia, and joint capsules — which progressively stretch and deform under the uncontrolled load.
What causes PTTD?
PTTD develops most commonly in middle-aged and older adults — women over 40 are the most frequently affected group — often in the context of a pre-existing flat or low-arched foot. Obesity places significant additional load on the posterior tibial tendon and is a strong risk factor. Diabetes and hypertension are associated with tendon degeneration through their effects on tissue vascularity. Previous ankle injuries and inflammatory arthropathies such as rheumatoid arthritis can also contribute.
The tendon is most vulnerable to degenerative change just posterior to the medial malleolus, where its blood supply is relatively poor — a zone of relative avascularity that heals poorly under cumulative stress.
What are the stages of PTTD?
PTTD is classified into four stages that guide both conservative and surgical management.
What are the symptoms?
Pain and swelling along the inner ankle and arch are the classic presenting symptoms, typically aggravated by standing, walking and activity. In early stages the pain is localised to the tendon just behind the medial malleolus. As the condition progresses, pain may shift to the outer ankle and foot as the peroneal tendons and lateral structures are stressed by the progressive deformity. The "too many toes" sign — where more toes than normal are visible when looking at the foot from behind — reflects the progressive forefoot abduction of established flatfoot deformity. Difficulty with single-leg heel raise — the most characteristic functional test — reflects the loss of posterior tibial tendon function.
How is it diagnosed?
Clinical assessment is the primary diagnostic tool — a physiotherapist will assess arch height, heel alignment, the single-leg heel raise test, and palpation of the posterior tibial tendon. The single-leg heel raise is pathognomonic when absent or severely limited — a healthy posterior tibial tendon should allow a confident single-leg heel raise; an inadequate one cannot. Ultrasound provides detailed imaging of the tendon — assessing for degeneration, partial tearing and tendon sheath effusion. MRI provides more comprehensive information about the tendon and surrounding structures, and weight-bearing X-rays assess the degree of bony deformity.
How can physiotherapy help?
For stage I and II PTTD, physiotherapy is highly effective and can halt or significantly slow progression, reducing pain and improving function without surgery.
The foundation of conservative management is offloading the degenerating tendon while rebuilding the active and passive support systems of the foot and ankle. Orthotic management — a medial arch-supporting foot orthosis or, in more significant cases, an ankle foot orthosis (AFO) — reduces the load on the posterior tibial tendon during standing and walking, providing the mechanical environment for healing and preventing further deformity progression.
Targeted strengthening of the tibialis posterior, intrinsic foot muscles, and calf complex addresses the active support deficit. Eccentric and isometric tibialis posterior exercises have the strongest evidence base for tendon rehabilitation and form the core of the strengthening program. Hip abductor and gluteal strengthening is equally important — improving the control of the lower limb kinetic chain reduces the valgus forces transmitted to the foot and ankle.
Real time ultrasound assists in assessing deep foot and ankle muscle activation and monitoring tendon healing progress. Clinical Pilates provides an excellent controlled environment for progressive foot, ankle and lower limb strengthening, with the reformer footbar allowing precise load modulation.
Footwear advice is an often overlooked but important component — supportive, motion-control footwear significantly reduces posterior tibial tendon load and complements orthotic management.
For patients whose PTTD has progressed to stage III or IV, or where conservative management has not been sufficient, flatfoot reconstruction surgery is the surgical pathway. Physiotherapy plays an important pre-operative preparation role and is central to post-surgical rehabilitation.
Arthritis Australia provides useful information on foot and ankle conditions associated with inflammatory arthritis for patients where rheumatoid arthritis or other inflammatory conditions are contributing to their PTTD.
Our physiotherapists Bethany Kippen and Emma Cameron both have experience in foot and ankle conditions and are members of the Australian Physiotherapy Association.
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.
Posterior tibial tendon dysfunction (PTTD) — also called adult acquired flatfoot deformity — is a progressive condition in which the posterior tibial tendon, the primary active support of the medial longitudinal arch of the foot, degenerates and gradually fails. As the tendon loses its ability to function effectively, the arch collapses, the heel rolls into valgus (outward), and the forefoot abducts — producing the characteristic flatfoot deformity that gives the condition its alternative name.
The posterior tibial muscle originates in the deep posterior compartment of the lower leg and its tendon passes behind the medial malleolus (the inner ankle bump) before inserting into the navicular and surrounding tarsal bones. In a healthy foot it actively inverts the heel and supports the arch during the propulsive phase of walking. When it fails, every step places abnormal stress on the passive stabilising structures of the midfoot — the spring ligament, plantar fascia, and joint capsules — which progressively stretch and deform under the uncontrolled load.
What causes PTTD?
PTTD develops most commonly in middle-aged and older adults — women over 40 are the most frequently affected group — often in the context of a pre-existing flat or low-arched foot. Obesity places significant additional load on the posterior tibial tendon and is a strong risk factor. Diabetes and hypertension are associated with tendon degeneration through their effects on tissue vascularity. Previous ankle injuries and inflammatory arthropathies such as rheumatoid arthritis can also contribute.
The tendon is most vulnerable to degenerative change just posterior to the medial malleolus, where its blood supply is relatively poor — a zone of relative avascularity that heals poorly under cumulative stress.
What are the stages of PTTD?
PTTD is classified into four stages that guide both conservative and surgical management.
- Stage I involves tendon inflammation and pain without significant deformity — the arch and heel alignment are still largely normal and the tendon is intact. This is the most treatable stage and responds very well to conservative physiotherapy management.
- Stage II involves partial tendon tearing and flexible flatfoot deformity — the arch has collapsed and the heel is in valgus, but the deformity can still be manually corrected. Most patients in stage II can be managed conservatively, though some require surgical intervention.
- Stage III involves rigid flatfoot deformity — the joints have adapted to the collapsed position and can no longer be manually corrected. Conservative management focuses on pain relief and function rather than deformity correction, and surgical options are often considered.
- Stage IV involves additional valgus tilt of the ankle joint itself above the fixed flatfoot deformity, representing the most advanced stage of the condition. This typically requires complex surgical reconstruction.
What are the symptoms?
Pain and swelling along the inner ankle and arch are the classic presenting symptoms, typically aggravated by standing, walking and activity. In early stages the pain is localised to the tendon just behind the medial malleolus. As the condition progresses, pain may shift to the outer ankle and foot as the peroneal tendons and lateral structures are stressed by the progressive deformity. The "too many toes" sign — where more toes than normal are visible when looking at the foot from behind — reflects the progressive forefoot abduction of established flatfoot deformity. Difficulty with single-leg heel raise — the most characteristic functional test — reflects the loss of posterior tibial tendon function.
How is it diagnosed?
Clinical assessment is the primary diagnostic tool — a physiotherapist will assess arch height, heel alignment, the single-leg heel raise test, and palpation of the posterior tibial tendon. The single-leg heel raise is pathognomonic when absent or severely limited — a healthy posterior tibial tendon should allow a confident single-leg heel raise; an inadequate one cannot. Ultrasound provides detailed imaging of the tendon — assessing for degeneration, partial tearing and tendon sheath effusion. MRI provides more comprehensive information about the tendon and surrounding structures, and weight-bearing X-rays assess the degree of bony deformity.
How can physiotherapy help?
For stage I and II PTTD, physiotherapy is highly effective and can halt or significantly slow progression, reducing pain and improving function without surgery.
The foundation of conservative management is offloading the degenerating tendon while rebuilding the active and passive support systems of the foot and ankle. Orthotic management — a medial arch-supporting foot orthosis or, in more significant cases, an ankle foot orthosis (AFO) — reduces the load on the posterior tibial tendon during standing and walking, providing the mechanical environment for healing and preventing further deformity progression.
Targeted strengthening of the tibialis posterior, intrinsic foot muscles, and calf complex addresses the active support deficit. Eccentric and isometric tibialis posterior exercises have the strongest evidence base for tendon rehabilitation and form the core of the strengthening program. Hip abductor and gluteal strengthening is equally important — improving the control of the lower limb kinetic chain reduces the valgus forces transmitted to the foot and ankle.
Real time ultrasound assists in assessing deep foot and ankle muscle activation and monitoring tendon healing progress. Clinical Pilates provides an excellent controlled environment for progressive foot, ankle and lower limb strengthening, with the reformer footbar allowing precise load modulation.
Footwear advice is an often overlooked but important component — supportive, motion-control footwear significantly reduces posterior tibial tendon load and complements orthotic management.
For patients whose PTTD has progressed to stage III or IV, or where conservative management has not been sufficient, flatfoot reconstruction surgery is the surgical pathway. Physiotherapy plays an important pre-operative preparation role and is central to post-surgical rehabilitation.
Arthritis Australia provides useful information on foot and ankle conditions associated with inflammatory arthritis for patients where rheumatoid arthritis or other inflammatory conditions are contributing to their PTTD.
Our physiotherapists Bethany Kippen and Emma Cameron both have experience in foot and ankle conditions and are members of the Australian Physiotherapy Association.
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.
