Technically the foot has at least four arches, although there are two major arches, the longitudinal arch, which extends along the length of the foot on the medial or inner side, under the instep from the joint to the heel; and the metatarsal arch, formed by the natural arching of the metatarsals at the joints of the foot.
The curved inside part of the foot, where the bones form a bridge from heel to ball.
The curved shape of the inner or medial side of the foot formed by the span between the heel and the joint
The foot has a natural arch on the inside, formed between the calaneum base and the beginning of the metatarsal joint. This is known as the longitudinal arch, and is usually the one referred to. There is another arch, the metatarsal arch, formed by the natural arching of the base of the metatarsals.
The upward curve at the side of the foot. Sometimes known as the longitudinal arch. Some authorities claim four different arches for the foot.
The bow-like upward curve on the bottom of your midfoot
The part of plantar that does not touch the ground. Most commonly used of metatarsal arch.