Flashcards in MSK Session 12- The Ankle Joint Deck (25)
What are the three joint types in the foot?
What is the function of the talus?
To transmit forces from the tibia to the calcaneus
What is the function of the calcaneus?
To transmit the forces from the talus to the ground.
What is the order of force transmission between the leg and foot?
What are the three articulations of the talus?
-superior= ankle joint. Between the talus, tibia and fibula.
-inferior= subtalar joint. Between the talus and the calcaneus.
-anterior= talonavicular joint. Between the talus and navicular.
What type of joint is the ankle joint?
Hinge type synovial joint
What is the ankle joint also known as?
The talocrural joint
What are the articulations of the ankle joint?
The talus, medial malleolus (lateral aspect), the lateral malleolus (medial aspect), the tibia and the fibula.
Which aspect of the talus is wider?
The anterior aspect
Which movement of the ankle joint is most stable and why?
Dorsiflexion because the anterior aspect of the talus is in the mortise completely.
Which movement of the ankle joint is the least stable and why?
Plantar flexion, because the posterior aspect of the talus is in the mortise, but it is thinner.
Which set of ligaments are the strongest?
What are the three parts of the medial/deltoid ligament?
The posterior tibiotalar ligament
The tibionavicular ligament
The tibiocalcaneal ligament
What is the function of the medial ligament?
Prevent overeversion of the foot
What is the function of the lateral ligament?
Prevent over inversion of the foot
What are the three parts to the lateral ligament?
Posterior talofibular ligament
Anterior talofibular ligament
Which muscles produce planarflexion of the foot?
The posterior leg muscles
Which muscles produce dorsiflexion of the foot?
The anterior leg muscles
Which muscles produce inversion? (2)
Tibialis anterior and posterior
Which muscles produce Eversion of the foot? (2)
Fibularis longus and brevis
What are the two movements of the ankle joint?
Plantar flexion and dorsiflexion
Which joints allow Eversion and inversion?
Subtalar, calcaneocuboid and talocalcaneonavicular joints
What is Potts fracture-dislocation?
Bi or tri malleolar fracture produced by over eversion of the foot.
The forced Eversion pulls on the strong medial ligament to cause an Eversion of the medial malleolus. This causes the talus to be displaced laterally and break the lateral malleolus. The tibia is forced anteriorly and may become damaged at the distal posterior site.
Which ligament is most at risk of irreversible damage due to an ankle sprain?
Anterior Talofibular ligament