the ankle and foot joint

Question 1

What is the talocrural joint?

Answer 1

The talocrural joint is the technically term for the ankle joint.

This is where the distal ends of the tibia and fibula make contact with each other and more importantly, the talus of the foot.

It is a synovial hinge joint, with dorsiflexion being the position of maximal stability.

Question 2

what are the major ligaments that support the ankle joint?

Answer 2

1. Medial and lateral collateral ligaments; these are triangular ligaments with their apex at the medial and lateral malleoli. They blend in with the joint capsule and enable flexion and extension.
2. Medial collateral ligament is also known as the deltoid ligament. It is comprised of tibionavicular, tibiocalcaneal and posterior tibiotalar ligaments superficially. The anterior tibiotalar ligament is deep.
3. Lateral collateral ligaments join the fibula to the foot. So the ligaments are the posterio tibiofibular, calcaneal fibular and anterior talofibular.

Note that in both sides, the anterior tibiofibular/tibiotalar ligaments are most likely to be sprained.

Question 3

Which muscles act on the ankle joint to enable dorsiflexion of the foot?

Answer 3

tibialis anterior, extensor digitorum longus and extensor hallicus longus (anterior compartment muscles do dorsiflexion and inversion of foot).

Question 4

which muscles act on the ankle joint to enable plantarflexion?

Answer 4

Gastrocnemius, soleus, plantaris, tibialis posterior, flexor digitorum longus and flexor hallicus longus.

(posterior compartment muscles contract to enable plantarflexion).

Question 5

What is the subtalar joint and how does it work?

Answer 5

The subtalar joint refers to the articulation of the talus’s medial side ontop of the medial side of the calcaneus.

It is a modified ball and socket joint, and enables inversion/eversion of the foot.

There is a slight gap between the joint called the sinus tarsi.

Question 6

what is the calcaneocuboid joint?

Answer 6

It is the joint between the calcaneus and the cuboid bone in front of it.

It is a plane synovial joint and allows pronation and supination.

Question 7

What are the ligaments of the tarsal bones?

Answer 7

1. Spring ligament- supports the medial longitudinal arch
2. interosseous talocalcaneal ligament
3. cervical ligament of the talus
4. Bifurcate ligament: these are two small ligaments that run accross from the calcaneus to the cuboid like bandaids holding them together.
5. Plantar aponeurosis- between the calcaneus and digits of the foot.
6. Short plantar ligament from calcaneus to the cuboid bone on the sole of the foot. Supports the lateral longitudinal arch.
7. Long plantar ligament from calcaneus, over the cuboid to the bases of the metatarsal bones.

Question 9

What are the ligaments and joints of the toe?

Answer 9

1. metatarsalphalangeal joints
2. interphalangeal joints
3. Deep transverse metatarsal ligament, which is a band that runs directly accross each of the phalangeal joints.
4. Volar plates are the small ligament bits that form the deep transverse ligament when joined together.
5. Collateral ligaments, on either side of the phalangeal jint capsules.