The plantar calcaneonavicular (spring) ligament is palpated for tenderness by applying pressure to the area immediately below the head of the talus, with the foot completely relaxed (Figs. 16-9 and 16-16). This ligament, which helps to support the longitudinal arch, can become strained and painful from overuse. Also one should probe the region of the long and short plantar ligaments, which also support the longitudinal arch of the foot, for point tenderness (Figs. 16-9 and 16-20). Foot pronation, sprain, or strain may result in acute pain.