Crural fascia

The crural fascia (Fascia cruris) is a solid fibrous sheath that envelops the leg and is continued from the tarse by the fascia of the foot. It has two overlapping laminas, a superficial one and a deep one.

-The superficial lamina continues the fascia lata and the femoral fascia. Very short and neglectable in Men, it extends further in domestic Mammals due to the development of the caudal femoral muscles: it unites intimately to the deep lamina around the middle or the distal third of the leg.

-The deep lamina has a more complex constitution. It starts in the popliteal region, where it covers the gastrocnemius muscle and attaches with him to the femur; it also unites cranially to the ligament system of the patella. More distally, it is reinforced by the extensions coming from terminal tendons of the biceps femoral muscle, semi-tendinous and gracile. extensions that extend in domestic Mammals until the calcaneus forming the reinforcement stripos of the back of the knee.. Its deep surface intimately adheres to the tibia's medial surface, that stays in this way widely discovered under the superficial lamina and the skin. It also sends several septums that insert between the muscular group to reach the fibula or the tibia delimitating the muscular compartments of the leg:

-the cranial tibial compartment contains the muscles of the craniolateral region, except the  lateral extensor of the digits or its derived and the long and short fibular muscle,

-the fibular compartment, delimitated bu the two fibular septums contains the latral extensor, the long and the short fibulars,

-the caudal compartment for the deep muscle of the caudal part of the leg,

-the sural compartment that holds the triceps sural and the surperficial flexor of the digits muscle.

Apart from the last one, that ends on the calcaneal tendon and on the calcneal tuber, these several compartments are continued around the tarsus by tendinous sheaths in this region.

At the limit between the leg and the foot, the crural fascia forms powerful transversal reinforcements destined to maintain the tendons: the retinaculums.