This tutorial is on the ankle joint. the ankle joint is this joint here between the talus, the tibia and the fibula. It’s a synovial hinge joint and the main movements that you get at this joint are dorsiflexion and plantar flexion. So one way of remembering which way is plantar flexion and dorsiflexion is if you just think of a plant on the floor and you want to squash that plant, you will press down in this direction. So plantar flexion is squashing a plant movement and dorsiflexion.
Is bringing the toes up to its head. So the distal ends of the fibula and the tibia essentially forms these sockets, which the talus slots into. So on either side of the talus, you’ve got the malleoli. So you’ve got the lateral malleolus of the fibula laterally forming the lateral wall of the socket. Medially, you’ve got the medial malleolus of the tibia forming the medial wall of the socket. And superiorly, the roof to the socket is formed by the inferior surface of the tibia.
I’ve just isolated these two bones, the tibia and the fibula. you can see the riff the socket formed by the inferior surface of the tibia bone and then you’ve got the medial malleolus and the lateral malleolus forming the walls of this socket. So the talus just slots into this socket formed by these two bones. So we’ll just take a quick look at some of the features of the distal tibia and fibula and the talus before going on to talk about the ligaments of this joint. So I pointed.
Out the lateral malleolus of the fibula and the medial malleolus of the tibia. there are some ligaments which bind these two bones together at the distal end. So this is the anterior tibiofibular ligament and this one posteriorly is the posterior tibiofibular ligament. The bones also are held together by the interosseus membrane as well. So this interosseus membrane is supported distally by these two ligaments.
If i just rotate around to the back, you can see there’s a groove on the back of the tibia on the medial surface. This is a groove for the tendon of the tibialis posterior muscle. You can see this muscle over here running behind that groove. And then laterally, you’ve got the malleolar fossa on the medial surface of the lateral malleolus and you’ve also got a groove for the fibularis longus muscle, so you can see this muscle running behind that groove or in that groove rather.
So we’ll just take a quick look at the talus bone as well. the talus bone obviously articulates above with the tibia and the fibula. Below, it articulates with the calcaneus and anteriorly, it articulates with the navicular. I’ve just isolated this bone and we’re looking at medially here. So it’s got a head anteriorly, a neck and a body. I’ve rotated it around. This is anterior now up here. You can see the body is slightly wider anteriorly. This means that when the foot is dorsiflexed, the.
Wider, anterior part gets wedged between the two malleoli. So the ankle joint is actually stabler in dorsiflexion. So we’ll take a look at the inferior surface. There’s various facets on the inferior surface, which articulate with the calcaneus, but we don’t need to worry about that in this tutorial. The superior surface, you can see it’s kind of domeshaped. It’s kind of cylindrical. This slots into that socket I showed you before.
So the upper surface articulates with the inferior surface of the tibia and this is called the trochlear surface. And then you’ve got the lateral surface which articulates with the lateral malleolus and you’ve got the medial surface, which articulates with the medial malleolus. So the joint capsule of the ankle joint consists of a fibrous and synovial membrane. So the synovial membrane attaches to the margins of these articular surfaces and it contains.