The leg is that part of the lower limb between the knee joint and ankle joint.
* Proximally, most major structures pass between the thigh and leg through or in relation to the poplitealfossa behind the knee.
* Distally, structures pass between the leg and foot mainly through the tarsal tunnel on the posteromedial side of the ankle, the exceptions being the anterior tibialartery and the ends of the deep and superficial fibular nerves, which enter the foot anterior to the ankle.
The bony framework of the leg consists of two bones, the tibia and fibula, arranged inparallel.
The fibula is much smaller than the tibia and is on the lateral side of the leg. It articulates superiorly with the inferior aspect of the lateral condyle of the proximal tibia, but does not takepart in formation of the knee joint. The distal end of the fibula is firmly anchored to the tibia by a fibrous joint and forms the lateral malleolus of the ankle joint.
The tibia is the weightbearingbone of the leg and is therefore much larger than the fibula. Above, it takes part in the formation of the knee joint and below it forms the medial malleolus and most of the bony surface forarticulation of the leg with the foot at the ankle joint.
The leg is divided into anterior (extensor), posterior (flexor), and lateral (fibular) compartments by:
* An interosseous membrane, which linksadjacent borders of the tibia and fibula along most of their length.
* Two intermuscular septa, which pass between the fibula and deep fascia surrounding the limb.
* By direct attachment ofthe deep fascia to the periosteum of the anterior and medial borders of the tibia .
Muscles in the anterior compartment of leg dorsiflex the ankle, extend the toes, and invert the foot. Muscles in theposterior compartment plantarflex the ankle, flex the toes, and invert the foot. Muscles in the lateral compartment evert the foot. Major nerves and vessels supply or pass through each compartment.