발의 족궁(Arches of Foot)

1. Anterior transverse arch : Formed by the cuneifroms, cuboid, and the bases of the metatarsals  

2. Lateral longitudinal arch : Formed by the calcaneus, cuboid, and the lateral 2 metatarsals  

3. Medial longitudinal arch : Formed by the calcaneus, talus, navicular, 3 cuneiform bones, and the medial 3 metatarsals

Functions

1) Support and divide the body weight about equally between the calcaneus and the heads of the metatarsal bones 

2) Propel the body in walking or running : allow the long flexors and the muscles of the foot to act on the bones of the fore part of the foot and toes(take-off part) and greatly assist the propulsive force of gatstrocnemius and soleus muscles 

3) Shock absorption 

4) Adapt to changes when walking on uneven surfaces

Factors maintaining arches 

1) Bones, ligaments, and muscles

2) Passive support : Ligament are sufficient to support the arches when standing still

3) Active support : Muscles are brought into action to support the arches during running or walking