Subtalar Joint Biomechanics From Normal to Pathologic

Subtalar joint biomechanics are primarily driven by the shape of the articulations with contributions from the surrounding soft tissues. The joint motion occurs about a single axis oriented medially and superiorly. Joint contact forces change during different stages of gait and are affected by hindfoot alignment and traumatic alterations to their normal anatomy. A valgus subtalar joint axis is likely a contributing, and perhaps primary, risk factor for progression to adult acquired flat foot. The subtalar joint axis also contributes to the clinical picture of a cavus foot and a special subset of patients with dynamic varus.