Ankle Bones

The foot is the region in the human lower limb where the lower leg connects with the proximal end of the foot. The foot enables us to maneuver the feet in varying directions.

Titles and Structure of the Bones in the Foot

Although commonly believed to contain just one joint, the foot is actually composed of two joints – the foot joint, also known as the tibiotalar or talocrural joint, and the subtalar joint. The following are the 4 bones that constitute the foot: 

1. Shinbone (Tibia)
2. Fibula
3. Talus
4. Heel bone (Calcaneus)

Foot Joint: This is a synovial joint, particularly a hinge joint between the tibia, fibula, and talus. This joint enables us to move the foot up and down (plantarflexion and dorsiflexion).

Subtalar Joint: Another synovial joint, it is situated beneath the foot joint. The bones that articulate to create this joint are the talus and calcaneus. This joint assists in turning the foot to the left and right (inversion and eversion).

Osseous Projections

There are numerous bony projections in the region that function as attachment points for the foot muscles and ligaments.

• The inside bony projection of the ankle can be felt as the medial malleolus; it is a part of the base of the tibia 
• The posterior malleolus is a bony bump at the back of the ankle; This is also a part of the base of the tibia
• The outer bony projection of the ankle can be felt as the lateral malleolus; it is the bony protrusion on the lower end of the fibula

Muscles and Tendons

Several muscles originating in the lower leg are responsible for all the movements of the foot and ankle. These include:

1. Calf muscles
2. Tibialis Posterior muscle
3. Peroneal Brevis
4. Peroneal Longus

The largest tendon in the human body, the Achilles tendon, is located in this region. It is where the calf muscles attach. Other important tendons here include:

1. Flexor hallux longus
2. Flexor digitorum
3. Anterior tibialis tendon
4. Posterior tibialis tendon
5. Peroneal tendons

Ligament Connections

1. Front and back talofibular ligament: Attaches the talus and fibula
2. Calcaneofibular ligament: Runs from the fibula to the calcaneus
3. Anterior tibiofibular ligament: Forms the connection between tibia and fibula.
4. Lateral collateral ligaments: Forms the connection between fibula and calcaneus; stabilizes the outer part of the foot.
5. Deltoid ligaments: Runs from the tibia to talus, calcaneus, and navicular bone; stabilizes the inner part of the foot.

References

1. The Basics Of Ankle Anatomy And Foot Anatomy – Csog.net
2. Ankle Anatomy – Arthritis.org
3. Parts Of The Ankle; Ankle Bone Anatomy – Arlingtonortho.com
4. Ankle – Image, Function, Conditions, & More – Webmd.com
5. Foot and ankle bones – Mayoclinic.org