Ankle Anatomy - InfoBarrel
The ankle comes from the Latin word angulus meaning bent. This is because the ankle is the bent junction between the foot and the leg. Although basic knowledge of the parts of the body may tell you that the ankle is a body part, it is in actuality a joint. The ankle or the talocrural joint connects the bones of the legs, the tibia and the fibula, with the talus bone of the foot. Ankle anatomy is important, because it enables mobility and flexibility of the lower extremities, allowing us to walk, run, swim.
Bones and ligaments comprising the ankle
The ankle is comprised of three main bones: the tibia, fibula, and the talus. The distal ends of the tibia and fibula are important to the ankle. The distal end and medial malleolus of the tibia articulate with the talus at the ankle joint. On the medial surface of the fibula is a triangular facet for the talus. Much of the articulation between the leg and the foot at the ankle joint is from the tibia compared to the fibula.
The talus or astragalus is a bone of the foot which has a rounded head, a neck and a cuboid body.
1) The head of the talus articulates with the navicular bone anteriorly and with the calcaneus inferiorly.
2) The neck has a groove in which the ligament of the talocalcaneal joint attaches.
3) The body articulates superiorly with the tibia, laterally and medially with the tibial and fibular malleoli and inferiorly with the calcaneus.
Interestingly, no muscles attach to the talus, but there are numerous ligaments associated with it.
The ligaments of the ankle are grouped into external (lateral) ligaments and medial (deltoid) ligament. These allow a level of flexibility and movement, but also limit it so that flexion and extension will not be too excessive. The most common form of ankle injury, the inversion sprain, is due to the tearing of the lateral ligaments.
Other functions of the ankle
The anatomy of the ankle is important in that not only does it allow the lower extremities flexibility and versatility in movement, it also is influential in the weight bearing capacity of the feet as well as in the stability of the body by positioning the center of gravity. The weight of the body is transmitted from the tibia to the talus, which distributes the weight anteriorly and posteriorly within the foot. The center of gravity on the other hand, passes slightly anterior to the ankle joint.
The ankle joint has one degree of freedom about a transverse axis which passes through the lateral malleolus and inferior to the medial malleolus. About this axis, flexion and extension occurs, which allows enough movement for the feet to enable us to walk, run, jump, swim, tiptoe and point our toes.
Bones making up the ankle anatomy is made up of the tibia, the fibula and the talus. It is a joint with one degree of freedom which allows flexion and extension of the foot about a transverse axis. It is a key structure in the movement of the lower extremities, especially the feet. Not only is it important for movement and flexibility, it is also pivotal in the stability not only of the feet, but of the body in general. In the erect position, the feet bears all of our weight, and the proper positioning of the center of gravity anterior to the ankle is key in keeping us balanced and stable.
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