What is the posterior tibial tendon?
The posterior tibial tendon runs from the calf muscle (tibialis posterior) behind the inner ankle bone (medial malleolus) and attaches to several bones on the underside of the foot. It is the primary dynamic stabiliser of the medial longitudinal arch — the main arch of your foot. Every time you push off the ground, this tendon locks the arch into a rigid lever for propulsion. Without it, the foot collapses inward and flattens.
Think of the posterior tibial tendon as a cable holding up a suspension bridge. While the bridge (your arch) has passive structural support from ligaments and bone shape, the cable (the tendon) provides the active tension that keeps it elevated under load. When the cable frays, the bridge sags — and eventually collapses.
How does PTTD develop?
PTTD is a progressive condition. It rarely appears overnight — instead, the tendon gradually degenerates over weeks or months of overload. In rugby, the combination of high running volumes, repeated change of direction, and heavy body mass creates significant demand on the posterior tibial tendon. Players who overpronate (feet roll inward excessively during gait) place disproportionate stress on this tendon with each stride.
The progression typically follows a predictable pattern: the tendon first becomes inflamed and painful (tendinopathy), then begins to stretch and elongate (losing its ability to support the arch), and finally may rupture or become so incompetent that the arch flattens permanently.
The four stages of PTTD
| Stage | What happens | Foot shape | Can you still play? |
|---|---|---|---|
| Stage I | Tendinopathy — the tendon is inflamed and painful but intact. No structural change to the foot. | Normal arch maintained | Yes — with orthotic support and load management |
| Stage II | The tendon has elongated. The arch begins to flatten. The deformity is flexible — it can be manually corrected. | Flexible flatfoot — arch drops under weight but can be restored | Possible with orthotics, but performance is affected |
| Stage III | The deformity has become rigid. The arch cannot be restored manually. Arthritic changes develop in the hindfoot joints. | Rigid flatfoot — arch is permanently collapsed | Unlikely without surgical intervention |
| Stage IV | The ankle joint itself is affected. The talus tilts within the ankle mortise due to deltoid ligament involvement. | Rigid flatfoot with ankle tilt | No — requires surgical management |
6-12 weeks
Stage I recovery
conservative management with orthotics
6-9 months
Stage II surgery
return-to-sport timeline if surgical
Gold standard
Single-leg heel raise
clinical screening test
Recognising the symptoms
The hallmark symptoms of PTTD develop gradually. Players often dismiss early signs as "just a sore ankle" or assume their arches have always been flat. Recognising the pattern early is critical — Stage I PTTD is highly manageable, while Stage III may end a career.
- Pain and swelling along the inner ankle — specifically behind and below the medial malleolus. This is where the tendon runs, and it is often tender to touch in early PTTD
- Progressive arch flattening — one foot gradually becomes flatter than the other. Compare both feet standing in front of a mirror. Asymmetric arch collapse is a strong indicator
- The "too many toes" sign — when viewed from behind, a flatfoot deformity causes the forefoot to abduct (point outward), making more toes visible on the outer side than normal. A coach or teammate can check this
- Inability to perform a single-leg heel raise — this is the definitive functional test. Stand on one leg and try to rise onto your toes. A healthy posterior tibial tendon locks the arch and allows a strong heel raise. A dysfunctional tendon cannot lock the arch, and the heel raise either fails completely or is weak and painful
- Pain worsening with activity — particularly with running, cutting, and pushing off. Rest relieves the pain initially, but as the condition progresses, even walking becomes uncomfortable
How PTTD differs from tibialis posterior tendinopathy
These terms are related but not interchangeable. Tibialis posterior tendinopathy refers to irritation, inflammation, or degeneration of the tendon itself — it corresponds to Stage I of PTTD. The tendon hurts, but the arch is still intact and the foot structure is normal. PTTD is the broader, progressive condition that encompasses tendinopathy as its earliest phase but continues through arch collapse and rigid deformity. A player with tibialis posterior tendinopathy has Stage I PTTD. A player with PTTD may be at Stage I, II, III, or IV.
Conservative management
Stage I and early Stage II PTTD respond well to conservative treatment. The goals are to reduce tendon pain, support the arch, and strengthen the tendon to prevent further degeneration:
- Custom orthotics — a rigid or semi-rigid orthotic with medial arch support reduces the load on the posterior tibial tendon by supporting the arch externally. This is the single most important conservative intervention and should be worn in training shoes, boots, and daily footwear
- Posterior tibial strengthening — resisted foot inversion, heel raises with emphasis on the arch-locking phase, and towel scrunches. Progress from bilateral to unilateral exercises as pain allows
- Load management — reduce running volume and avoid high-speed cutting during the acute phase. Maintain fitness through low-impact activities (cycling, pool running) that do not load the tendon
- Footwear assessment — avoid unsupportive footwear (flip-flops, flat shoes). Training shoes should have structured medial support. Some players benefit from motion-control running shoes for conditioning sessions
- Anti-inflammatory strategies — ice after training, topical anti-inflammatory gel over the tendon. Oral NSAIDs can be used short-term under medical supervision but do not address the underlying mechanical problem
When is surgery needed?
Surgery is considered when conservative management fails to control symptoms at Stage I/II, or when the condition has progressed to Stage III or IV. Surgical options depend on the stage:
- Stage I — tendon debridement (removing damaged tissue) and synovectomy. Recovery: 3-4 months
- Stage II — tendon transfer (typically the flexor digitorum longus tendon is transferred to replace the failed posterior tibial tendon) combined with a calcaneal osteotomy to realign the heel. Recovery: 6-9 months
- Stage III — triple arthrodesis (fusion of the subtalar, talonavicular, and calcaneocuboid joints). This eliminates the deformity but also eliminates hindfoot motion. Recovery: 9-12 months. Return to competitive rugby is uncertain
- Stage IV — ankle reconstruction or fusion in addition to the hindfoot procedures. Return to competitive sport is unlikely