The foot is a very complex body part with 26 bones and so many more joints and even more ligaments. Plus tendons, muscles and other soft tissues!
Bones of the foot
The foot is made up of a total of 26 bones, 2 in the rear-foot (or hind-foot), 5 in the mid-foot and 19 making up the forefoot and toes.
The rear foot consists of the Talus and Calcaneus. The Talus is the uppermost bone of the foot which connects the foot to the ankle by forming a joint with the Tibia and Fibula bones of the lower leg. The calcaneus sits underneath the Talus and forms the heel bone.
Moving forwards up the foot, the mid-foot consists of the Cuboid on the outside of the foot and the Navicular next to this on the inside of the foot. The remaining 3 bones are known as the Cuneiforms (medial, intermediate and lateral) and are situated in front of the Navicular. All 5 of these bones are collectively known as the Tarsals and form the arch of the foot.
The forefoot is made up of 5 Metatarsals (labelled 1-5 starting at the big toe), and 14 Phalanges, 3 forming each toe with the exception of the big toe (or Hallux) which only has 2 Phalanges.
Ligaments of the foot
As ligaments have the job of connecting and holding bones together to form joints, I’m sure you can imagine that there are a lot of ligaments within the foot. As well as holding these bones together, the ligaments of the foot have the task of maintaining the arched shape. The longitudinal arch of the foot is supported mainly by the long, thick ligament known as the Plantar Fascia, Plantar Aponuerosis or Long Plantar Ligament. This runs from the bottom of the calcaneus (heel bone) along the length of the sole of the foot to attach to the Metatarsals.
Other important ligaments include the Plantar Calcaneonavicular Ligament (also known as the spring ligament), important in supporting the head of the Talus, and the Plantar Calcaneocuboid Ligament (or short plantar ligament) which aids the Plantar Fascia in supporting the longitudinal arch of the foot.
Muscles of the foot are classed as either intrinsic or extrinsic. Intrinsic muscles are those which have both attachments within the foot and control the movement of the toes. Several of these muscles also help the ligaments with supporting the arch of the foot.
Extrinsic muscles originate from anywhere in the lower leg, their long tendons cross the ankle joint and insert onto one of the bones of the foot.