The fascia lata is an investment for the whole of the thigh, but varies in thickness in different parts. It is thicker in the upper and lateral part of the thigh, where it receives a fibrous expansion from the
gluteus maximus, and where the
tensor fasciae latae is inserted between its layers; it is very thin behind and at the upper and medial part, where it covers the
adductor muscles, and again becomes stronger around the knee, receiving fibrous expansions from the tendon of the
biceps femoris laterally, from the
sartorius medially, and from the
quadriceps femoris in front.
Function The fascia lata surrounds the tensor fasciae latae muscle. It is a fibrous sheath that encircles the thigh subcutaneously. This encircling of the muscle allows the muscles to be bound together tightly.
Above and behind The fascia lata is attached, above and behind (i.e. proximal and posterior), to the back of the
sacrum and
coccyx; laterally, to the
iliac crest; in front, to the
inguinal ligament, and to the
superior ramus of the
pubis; and medially, to the
inferior ramus of the pubis, to the inferior ramus and tuberosity of the
ischium, and to the lower border of the
sacrotuberous ligament. From its attachment to the iliac crest it passes down over the
gluteus medius to the upper border of the
gluteus maximus, where it splits into two layers, one passing superficial to and the other beneath this muscle; at the lower border of the muscle the two layers reunite.
Laterally Laterally, the fascia lata receives the greater part of the tendon of insertion of the gluteus maximus, and becomes proportionately thickened. The portion of the fascia lata attached to the front part of the iliac crest, and corresponding to the origin of the tensor fasciae latae, extends down the lateral side of the thigh as two layers, one superficial to and the other beneath this muscle; at the lower end of the muscle these two layers unite and form a strong band, having first received the insertion of the muscle. This band is continued downward under the name of the
iliotibial band and is attached to the lateral condyle of the
tibia. The part of the iliotibial band which lies beneath the
tensor fasciae latae is prolonged upward to join the lateral part of the capsule of the
hip joint.
Below Below, the fascia lata is attached to all the prominent points around the
knee joint, viz., the
condyles of the femur and tibia, and the
head of the fibula. On either side of the
kneecap it is strengthened by transverse fibers from the lower parts of the vasti muscles (three of the four
quadriceps) which are attached to and support this bone. Of these the lateral are the stronger, and are continuous with the iliotibial band. The deep surface of the fascia lata gives off two strong intermuscular septa, which are attached to the whole length of the
linea aspera and its prolongations above and below; the
lateral intermuscular septum, the stronger of the two, extends from the insertion of the
gluteus maximus to the
lateral condyle, separates the
vastus lateralis in front from the short head of the
biceps femoris behind, and gives partial origin to these muscles; the
medial intermuscular septum is the thinner one and separates the
vastus medialis from the
adductor muscles. Besides these there are numerous smaller septa, separating the individual muscles, and enclosing each in a distinct sheath.
Deep fascia of leg The
deep fascia of the lower leg is a continuation of the fascia lata. ==Clinical significance==