The inferior extensor retinaculum of the foot (cruciate crural ligament, lower part of anterior annular ligament) is a Y-shaped band placed in front of the
ankle-joint
The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular ...
, the stem of the Y being attached laterally to the upper surface of the
calcaneus
In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.
...
, in front of the depression for the
interosseous talocalcaneal ligament; it is directed medialward as a double layer, one lamina passing in front of, and the other behind, the tendons of the
peroneus tertius
In human anatomy, the fibularis tertius (also known as the peroneus tertius) is a muscle in the anterior compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body ( eversion) and to pull the foot upward towar ...
and
extensor digitorum longus
The extensor digitorum longus is a pennate muscle, situated at the lateral part of the front of the leg.
Origin and insertion
It arises from the lateral condyle of the tibia; from the upper three-quarters of the anterior surface of the body of ...
.
At the medial border of the latter tendon, these two layers join, forming a compartment in which the tendons are enclosed.
From the medial extremity of this sheath, the two limbs of the Y diverge: one is directed upward and medialward, to be attached to the
tibial malleolus
A malleolus is the bony prominence on each side of the human ankle.
Each leg is supported by two bones, the tibia on the inner side (medial) of the leg and the fibula on the outer side (lateral) of the leg. The medial malleolus is the promi ...
, passing over the
extensor hallucis longus and the vessels and nerves but enclosing the
tibialis anterior by a splitting of its fibers.
The other limb extends downward and medialward, to be attached to the border of the
plantar aponeurosis
The plantar fascia is the thick connective tissue ( aponeurosis) which supports the arch on the bottom ( plantar side) of the foot. It runs from the tuberosity of the calcaneus (heel bone) forward to the heads of the metatarsal bones (the bon ...
, and passes over the tendons of the extensor hallucis longus and tibialis anterior and also the vessels and nerves.
Additional images
File:Gray437.png, Muscles of the front of the leg.
File:Slide2ALE.JPG, Inferior extensor retinaculum of foot.Deep dissection.
See also
*
Cruciate ligament
Cruciate ligaments (also cruciform ligaments) are pairs of ligaments arranged like a letter X. They occur in several joints of the body, such as the knee joint and the atlanto-axial joint. In a fashion similar to the cords in a toy Jacob's la ...
References
{{Authority control
Lower limb anatomy