ankle

3. Ankle joint, also known as talocrural joint,
consists of a deep socket formed by the lower
ends of the tibia and fibula, into which the
upper part of the body of talus fits.
It is approximately a uniaxial hinge joint, where
movements are possible through only one axis.
The talus moves on a transverse axis and
produces dorsiflexion and plantar flexion of the
foot.
The shape of articulating bones, strength of the
ligaments and the surrounding tendons make
this joint strong and stable.

5. Articular surfaces of ankle joints
The articulation takes place between the lower end of tibia, the two
malleoli and the body of talus. All of these are covered with articular
cartilage. The socket created by the medial and lateral malleoli, into
which the body of talus fits, is deepened by the inferior transverse
tibiofibular ligament.

6. Ligaments of ankle joint:
Two important ligaments are associated with this joint: Medial ligament and Lateral
ligament.
•Medial Ligament: Also known as deltoid ligament, it is the stronger of the two
important ligaments of ankle joint. It is attached by its apex to the tip of the medial
malleolus. Below it has two places of attachment. The deep fibers are attached to the
non-articular area on the body of talus. The superficial fibers are attached to medial
side of talus, sustentaculumtali and the tuberosity of navicular bone. The medial
ligament consists of 4 bands.
Posterior tibiotalar ligament
Anterior tibiotalar ligament
Tibiocalcaneal ligament
Tibionavicular ligament
•Lateral ligament: It is weaker than the medial ligament and consists of three bands;
Anterior tibiofibular ligament: It runs from the lateral malleolus to the lateral
surface of talus.
Calcaneofibular ligament: It runs from the tip of lateral malleolus to lateral
surface of calcaneum.
Posterior talofibular ligament: It runs from the lateral malleolus to the
posterior tubercle of the talus

8. Blood supply of ankle joint:
The ankle joint receives its blood supply form
malleolar rami of the anterior and posterior tibial and
peroneal arteries.
Lymphatic drainage of ankle joint:
Lymphatic drainage is through the vessels
accompanying the arteries.
Nerve supply to ankle joint:
The ankle joint receives its nerve supply from deep
peroneal, saphenous, sural and tibial nerves.
Occasionally, the superficial peroneal nerve also
supplies the ankle joint.

9. Movements of ankle joint:
As stated above, the ankle joint is a uniaxial hinge joint permitting only
two types of movements: Dorsiflexion and Plantar flexion. The
movements of inversion and eversion of foot seem to occur and ankle
but actually they take place at the tarsal joints.
•Dorsiflexion: It is the movement in which the dorsal surface of foot is
flexed. In this movement the toes point upward. Muscles responsible for
it include;
Tibialis anterior
Extensor hallusiclongus
Extensor digitorumlongus
Peroneus tertius
Dorsiflexion is limited by the tension of the tendo calcaneus (Achilles’
tendon), posterior fibers of the medial ligament and the calcaneofibular
ligament.

10. •Plantar flexion: It is the movement of foot in which its plantar surface
is flexed. The toes point downward in this movement. Muscles
responsible for plantar flexion include;
Gastrocnemius
Soleus
Plantaris
Peroneus longus
Peroneus brevis
Tibialis posterior
Flexor digitorumlongus
Flexor hallucislongus.
From the above list of muscles, it is quite clear that more muscle mass is
involved in plantar flexion than in dorsiflexion, therefore, plantar flexion
is much more powerful. It is limited by the tension of the opposing
muscles, the anterior fibers of the medial ligament and the anterior
talofibular ligament