Which physical finding is most characteristic of posterior tibial tendon dysfunction?

• A. Pain along posterior tibial tendon
• B. Swelling in the ankle
• C. Flatfoot deformity with a positive too many toes sign
• D. High arches

Answer: (C)

Posterior tibial tendon dysfunction undermines the tendon that normally supports the medial arch. When this tendon fails, the arch collapses under load, the hindfoot goes into valgus, and the forefoot abducts, producing a flatfoot deformity. This structural change is the most characteristic finding, and the “too many toes” sign is a classic clue: from behind, the collapsed arch and forefoot abduction let more toes be seen than normal on the affected foot. Pain along the tendon and mild ankle swelling can occur, but they are less specific. High arches would point away from this condition, since PTTD is associated with flattening, not an elevated arch.