Lecture 5: The Foot and Ankle Flashcards
What articulations are present at the ankle joint?
Articulations between the distal tibia and fibula with the talus
What kind of joint is the ankle joint?
Synovial hinge joint permitting two movements – dorsiflexion and plantar flexion
What factors contribute to the stability of the ankle joint?
- Good congruity between malleolar mortice and trochlea – the malleoli ‘grip’ the talus
- Very strong ligaments between the bones of the ankle joint including:
- distal part of the interosseous membrane
- anterior and posterior tibiofibular ligaments
Why is the ankle most stable during dorsiflexion?
- The trochlea of the talus is wider anteriorly than posteriorly
- During dorsiflexion, the anterior part of the trochlea moves between the malleoli
- This spreads the tibia and fibula slightly, increasing their grip on the talus
What are the lateral ligaments of the ankle joint?
Anterior talofibular ligament
Posterior talofibular ligament
Calcaneofibular ligament (weakest)
What are the medial ligaments of the ankle joint?
The medial ligament is attached to the medial malleolus and fans out to attach to the talus, navicular and calcaneus
Also called deltoid ligament due to it’s resemblance to the Greek letter delta
What movements are present at the ankle joint?
Dorsiflexion
Plantarflexion
Inversion
Eversion
Which muscles are involved in plantarflexion?
Muscles:
- posterior compartment of the leg
(except popliteus)
Supplied by the:
- tibial nerve
- posterior tibial artery
Which muscles are involved in dorsiflexion?
Muscles:
- anterior compartment of the leg
Supplied by the:
- deep fibular (peroneal) nerve
- anterior tibial artery
Where do inversion and eversion primarily occur?
At the subtalar joint with some movement in the transverse tarsal joint.
What is the cause of most ankle sprains?
Most ankle sprains are inversion injuries with twisting of a plantar-flexed foot.
Why do ankle sprains heal slowly?
Ligaments are relatively avascular.
