Adult-acquired flatfoot deformity is a frequent clinical entity leading to invalidating symptoms in middle-aged patients. In this video, we revisit the anatomy of the static stabilizing structures of the medial longitudinal foot arch. These structures include the plantar fascia; the talocalcaneal interosseous ligament; and the spring ligament complex, consisting of the tibionavicular portion of the superficial deltoid ligament, the superomedial bundle of the calcaneonavicular ligament, and the inferior bundle of the calcaneonavicular ligament. With the help of a gait simulator, we illustrate the effect of sectioning these ligaments. Based on the anatomic characteristics, we suggest a reconstruction technique to repair the spring ligament complex.