In analyzing a normal day of school or work, we use a countless number of muscles, ligaments, tendons, and many other anatomical structures in order to carry out normal functions. Walking, for example, is taken for granted by most people because it is something we need to go about our day. By not being able to walk, life becomes very challenging and a daily struggle to accomplish simple tasks such as going to class or getting around your living environment. One structure extremely important to walking is the ankle. The ankle brings together two very important structures- the leg and the foot- which in turn makes it a vital structure in itself, worthy of exploring.
First off, the ankle is made up of four main bones: tibia, fibula, talus, and calcaneus. It includes the lower, or distal, ends of the tibia and fibula. On those distal ends are two bony landmarks known as the medial malleolus on the tibia and the lateral malleolus on the fibula. Medial refers to the structure being located closer to the spine/midline and lateral refers to the location as farther from midline. Therefore, the medial and not the lateral malleoli is located on the distal end of the tibia because the tibia is the more medially located bone. Therefore the medial malleoli goes hand in hand with the tibia. These bony landmarks are protrusions that exist horizontally and inferiorly which help to increase the range of motion of the tendons in the muscles that run posterior to them. In addition, the talus is another bone that sits directly under and articulates with the tibia. The glossy covering on the joint surface articulates with the similar glossy undersurface of tibia allowing the ankle to glide smooth and effortlessly. (Foot and Ankle Anatomy, 2011). The calcaneus bone sits directly below the talus and is otherwise known as the heel bone. The articulation of the distal tibia and superior talus along with the distal, medial fibula with the lateral talus all work together to form the talocrural joint. Also known as the ankle joint, it falls under the category of a diarthrodial joint. This type of joint is freely movable and has a considerable separation between the particular bones that are involved. The separation creates the feature of a joint cavity that surrounds the space created. However, it is not just a diarthrodial joint; rather it has a more specific classification. There are many types of diarthrodial joints, but the ankle is classified as a ginglymus or hinge joint. This means it has a broad range of motion, but only through one plane- the sagittal plane. There are three planes that cut the body into different sections and the sagittal plane divides the body into two symmetrical, right and left halves. The general physiological movements that occur in this plane are flexion and extension and because it moves through only the sagittal plane, it has one degree freedom of motion. The physiological movements that are actually specific to the ankle are dorsiflexion (flexion) and palmar flexion (extension). Dorsiflexion occurs when the dorsal, or top, portion of that foot moves toward the anterior tibia decreasing the angle between the foot and shin. An example of dorsiflexion would be simply flexing your foot. Palmar flexion is just the opposite in that it occurs when the plantar, or bottom, portion of the foot moves away from the anterior tibia increasing the angle once again. An example of palmar flexion would then be pointing the foot.
Another joint associated with the ankle is the inferior tibiofibular joint. This joint is formed by the distal ends of the tibia and fibula. Since this is the inferior tibiofibular joint, there has to be a superior tibiofibular joint and there is! However, it is not associated with the ankle is located at the proximal ends of this bones where the knee. The inferior tibiofibular joint is a strong, fibrous joint of, more specifically, syndesmosis classification and provides a...
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