Foot
Progressive Collapsing Foot Deformity
Also known as Adult Acquired Flatfoot, formerly Tibialis Posterior Dysfunction
About Your Condition
Adult acquired flatfoot is a progressive condition in which the arch of the foot gradually collapses over time. The most common underlying cause is dysfunction of the posterior tibial tendon — the main tendon responsible for supporting the inner arch. When this tendon becomes painful, weakened, or torn, the arch is no longer adequately supported and begins to flatten.
The condition is described in stages, which help guide treatment: Stage I, where the tendon is inflamed and painful but structurally intact and the arch is preserved; Stage II, where the tendon has become elongated and dysfunctional and the arch collapses under load but can still be passively corrected; Stage III, where the hindfoot has become rigid with secondary arthritis and can no longer be passively corrected; and Stage IV, where the deformity has progressed to involve the ankle joint itself.
In many patients, early-stage (Stage I–II) flatfoot remains stable for years with appropriate orthotic support and physiotherapy; in others, particularly those with significant tendon damage, progression is more likely.
Non-Operative Management
A structured combination of orthotic support and physiotherapy is the foundation of non-operative management.
Orthotics and Bracing
- A medial arch-supporting orthotic is the cornerstone of conservative management, reducing load on the posterior tibial tendon by mechanically supporting the arch position.
- In acute presentations, a period in a walking boot may be used to rest the tendon before transitioning to an orthotic. A genuine trial of at least three to six months with a properly fitted orthotic is recommended before considering surgery, and many patients achieve satisfactory long-term control without ever requiring it.
Footwear
- Supportive, stable footwear with a firm heel counter and good arch support is essential. Flat, flexible shoes provide no support for the collapsing arch.
- A motion-control or anti-pronation jogger with strong medial arch support should be the default, everyday shoe — not just for exercise — as it helps offload the tibialis posterior tendon throughout the day.
Physiotherapy Protocol
- A staged approach is recommended, moving from settling the acute phase through to strengthening once symptoms allow, aiming for around 5–10 minutes, 2–3 times a day.
- Stage 1 — settling the acute phase: relative rest, low-impact cross-training, icing the inner ankle for 10–15 minutes after activity, and gentle pain-free range of motion. This stage is about pain relief, not strengthening — loading the tendon too early can worsen symptoms and delay recovery.
- Stage 2 — strengthening, once the acute phase has settled: resisted inversion with a resistance band, eccentric-concentric heel raises, calf stretching, short foot / doming exercises, and single-leg balance work, progressing gradually and guided by symptoms.
When to Consider Surgery
Surgery is considered when symptoms significantly limit your daily activities despite an adequate trial of non-operative treatment, or when the deformity is progressive and has reached a stage where conservative measures can no longer accommodate it.
Surgical reconstruction of the flatfoot is a tailored procedure, built around the specific deformity present in each patient's foot.