Generality
The ankle is the synovial joint of the human body, located at the distal ends of the fibula and tibia (leg bones) and at the proximal end of the talus (one of the 7 tarsal bone elements of the foot).
The ankle has a complex system of ligaments: the medial ligaments, which are 4 in total, and the lateral ligaments, which are 3 in all.
These structures, together with the fibula-tibia-thalus synergy, allow the foot to perform two opposite movements: dorsiflexion and plantarflexion.
Dorsiflexion is when you lift your feet and walk on your heels; plantarflexion, on the other hand, is when you stand on your toes.
Very common injuries to the ankle joint are sprains. Following a sprain, the ligaments in the ankle can be stretched or broken.
What is the ankle?
The ankle is the synovial joint of the human body, located between leg and foot, exactly where three bones meet: tibia, fibula and talus (or talus).
The tibia and fibula are the two bones that make up the leg; the talus, on the other hand, is one of the seven bones that form the tarsal group of the foot.
BRIEF ANATOMICAL RECALL OF THE FOOT
Anatomists divide the bones of the foot into three groups: the tarsal (or tarsal group) bones, the metatarsal (or metatarsal group) bones, and the phalanges.
The metatarsal bones are 5, arranged parallel to each other. They are long bones, at the ends of which the phalanges articulate.
Finally, the phalanges are 14 and form the toes. Except the big toe which is made up of 2 phalanges, all the other toes have 3 for each.
PUNCTUALIZATION ON THE MEANING OF THE ANKLE
The definition of ankle, given a little while, is actually the one known to most people and that is used in common speech.
However, it should be noted that, in purely medical-anatomical language, the term ankle identifies the "set of three joints: the" talocrural (or tibio-tarsal) joint, the "subtalar joint and the" lower tibio-fibular joint (or tibio - inferior peroneal).
Of these three articular elements, the talocrural articulation corresponds to the ankle in common parlance; in fact it is also known as ankle proper.
EXAMPLE OF DIARTHROSIS
The ankle is an example of a movable joint or diarthrosis. These joints allow a wide range of motion, in one or more directions of space.
Other examples of diarthrosis are the knee, shoulder and fingers.
Anatomy
The ankle joint connects the distal ends of the tibia and fibula with the proximal end of the talus:
- Held together by the lower tibio-fibular ligaments (anterior and posterior), the ends of the tibia and fibula form, on the lower margin, a concave hoof, called a mortar and covered with cartilage.
- The talus "inserts" inside the mortar with its region, which takes the name of body.
The body of the talus has a conical shape; in fact, it is wide on the front (front) and narrow on the back (rear).
To stabilize this bony accommodation, are a series of ligaments (which will be treated separately) and the two malleoli, the tibial and the fibular.
The tibial malleolus and the fibular malleolus are two bony processes, located, respectively, on the medial margin of the tibia and on the lateral margin of the fibula. It is no coincidence that the tibial malleolus also takes the name of medial malleolus, while the peroneal malleolus also takes the second term of lateral malleolus.
LIGAMENTS
To hold together the bony ends constituting the ankle, are two groups of ligaments:
- The medial or deltoid ligaments. The medial ligaments are four separate elements, which join the tibial / medial malleolus to the talus in two points (anterior tibial and posterior tibial ligaments), to the calcaneus (tibio-calcaneal ligament) and to the navicular bone (tibio- navicular).
- The lateral ligaments. The lateral ligaments are three separate elements, which join the fibular / lateral malleolus to the talus in two points (anterior and posterior talofibular ligaments) and to the calcaneus (calcaneofibular ligament).
Figure: the medial (or deltoid) ligaments of the ankle. As can be seen, the anterior talo-tibial ligament joins the malleolus of the tibia to the anterior-medial region of the talus, while the posterior tibial-tibial ligament joins the malleolus of the tibia to the posterior-medial portion of the talus.
From the site: gymnasticsinjuries.wordpress.com
Figure: the lateral ligaments of the ankle. The anterior talofibular ligament joins the malleolus of the fibula to the anterior-lateral region of the talus; the posterior talo-fibular ligament puts the malleolus of the fibula in communication with the posterior-lateral region of the talus; finally, the calcaneofibular ligament connects the malleolus of the fibula with the calcaneus. From https://en.wikipedia.org/wiki/Ankle
TENDONS
To support the ankle, several tendons participate. Structurally, a tendon looks a lot like a ligament; the only (and substantial) difference from the latter is that it connects a muscle to a bone (N.B: a ligament connects two bones).
The tendons in close contact with the ankle joint are:
- The Achilles tendon. Connects the calf muscles (the twins and the soleus) to the calcaneal bone. It is essential for walking, running and jumping. Its breakage severely limits a person's motor skills.
- The anterior tibial tendon. Connects the anterior tibialis muscle to a medial tarsal bone of the foot.
- The posterior tibial tendon. Joins the posterior tibial muscle to the tarsal bones.
- The peroneal tendons. They join the peroneal muscles to the lateral bones of the tarsal region of the foot. They slide sideways to the ankle.
NERVES
At least three nerves pass next to the ankle.
The most important is the tibial nerve, a branch (or branch) of the sciatic nerve that runs through the posterior compartment of the leg and reaches the sole of the foot.
The other two nerves pass, one, in front of the ankle and, another, on its lateral edge.
Functions
The ankle allows the foot to perform two fundamental and opposite movements: plantarflexion and dorsiflexion.
Plantarflexion is the movement that allows you to point the foot towards the floor. The human being makes a plantarflexion movement when trying to walk on toes.
Dorsiflexion, on the other hand, is the movement that allows you to lift the foot and walk on the heels.
Both of these movements require the involvement of several muscles; In the case:
- For the plantarflexion movement, the twin muscles (of the calf), the soleus muscle (of the calf), the plantar muscle and the posterior tibial muscle are needed.
- For the dorsiflexion movement, the anterior tibialis muscle, the extensor muscle of the big toe and the extensor muscle of the fingers are needed.
* Note: the reader may notice that some of the muscles involved in the ankle movements are the same as previously mentioned when discussing tendons.
LATERAL MOVEMENTS
In fact, thanks to its ligaments, the ankle also enjoys some lateral mobility. This property guarantees the human being to walk on uneven surfaces.
Clearly, it has limitations, which, if exceeded, can cause the ligaments in the ankle to be strained or damaged.
Diseases of the Ankle
The most common problems that can affect the ankle are the stretching and rupture of the ligaments that join the various bony parts involved in the joint.
These two conditions take the general name of ankle sprain, with reference to the fact that, often, the stretching and rupture of the ligaments is the consequence of an abnormal movement of the joint.
The ligaments most involved in sprains are the lateral ligaments, as the latter are weaker than the medial ligaments.
FRACTURE OF THE ANKLE
Another major injury that the ankle can suffer - albeit less frequently than sprains - is the so-called bimalleolar or trimalleolar Pott fracture.
Typically, this ankle injury is the result of a marked eversion movement of the foot.
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