When weight, energy and the forces from locomotion, on the foot are considered, there is no wonder that foot problems are commonplace.

Foot problems often center around the arch of the foot or the lack thereof. The maintenance of the arch is critical to normal bipedal stance and locomotion. The plantar aponeurosis and several plantar ligaments, in combination with extrinsic leg muscles, and intrinsic foot muscles work toward maintaining a healthy arch.

The plantar aponeurosis is a tough deep fascial sheet that overlies the sole of the foot. It runs from the calcaneus to the bases of the proximal digits, and helps maintain the arch of the foot. It obviously protects deeper foot structures. Notice how this aponeurosis is very similar to the palmer aponeurosis of the hand.

Two plantar ligaments stand out as important due to their role in maintaining the arch. The "spring" (plantar calcaneal navicular) ligament connects the calcaneus and navicular bones and prevents them from spreading apart under body weight, delivered through the talus bone. The long and short plantar ligaments join the calcaneus with bases of the cuboid and metatarsal bones. These ligaments also keep those bones together assisting in arch maintenance.