The tensor fasciae latae (or tensor fasciæ latæ or, formerly, tensor vaginae femoris) is a
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
of the
thigh
In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...
. Together with the
gluteus maximus
The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human ...
, it acts on the iliotibial band and is continuous with the
iliotibial tract
The iliotibial tract or iliotibial band (ITB; also known as Maissiat's band or the IT band) is a longitudinal fibrous reinforcement of the fascia lata. The action of the muscles associated with the ITB ( tensor fasciae latae and some fibers of ...
, which attaches to the
tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
. The muscle assists in keeping the balance of the
pelvis
The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton).
The ...
while standing, walking, or running.
Structure
It arises from the anterior part of the outer lip of the
iliac crest
The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
Structure
The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the posterior ...
; from the outer surface of the
anterior superior iliac spine
The anterior superior iliac spine (abbreviated: ASIS) is a bony projection of the iliac bone, and an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis. It provides attachment for the ing ...
, and part of the outer border of the notch below it, between the
gluteus medius
The gluteus medius, one of the three gluteal muscles, is a broad, thick, radiating muscle. It is situated on the outer surface of the pelvis.
Its posterior third is covered by the gluteus maximus, its anterior two-thirds by the gluteal aponeu ...
and
sartorius; and from the deep surface of the
fascia lata.
It is inserted between the two layers of the iliotibial tract of the fascia lata about the junction of the middle and upper thirds of the thigh. The tensor fasciae latae tautens the iliotibial tract and braces the knee, especially when the opposite foot is lifted.
[Saladin, Kenneth. Anatomy and Physiology. 6th ed. Mc-Graw Hill. 2010.] The terminal insertion point lies on the lateral condyle of the tibia.
[Saladin, Kenneth. Anatomy and Physiology. 5th ed. Mc-Graw Hill. 2010.]
Nerve supply
Tensor fasciae latae is innervated by the superior gluteal nerve, L5 and S1. At its origins of the anterior rami of L4, L5, and S1 nerves, the superior gluteal nerve exits the pelvis via greater sciatic foramen superior to the piriformis. The nerve also courses between the gluteus medius and minimus. The superior gluteal artery also supplies the tensor fasciae latae.
The superior gluteal nerve arises from the sacral plexus and only has muscular innervation associated with it. There is no cutaneous innervation for sensation that stems from the superior gluteal nerve.
Function
The tensor fasciae latae is a tensor of the fascia lata; continuing its action, the oblique direction of its fibers enables it to stabilize the hip in extension (assists gluteus maximus during hip extension). The fascia lata is a fibrous sheath that encircles the thigh like a subcutaneous stocking and tightly binds its muscles. On the lateral surface, it combines with the tendons of the gluteus maximus and tensor fasciae latae to form the iliotibial tract, which extends from the iliac crest to the lateral condyle of the tibia.
In the erect posture, acting from below, it will serve to steady the pelvis upon the
head of the femur; and by means of the iliotibial tract it steadies the
condyle
A condyle (;Entry "condyle"
in
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
on the articular surfaces of the tibia, and assists the gluteus maximus in supporting the knee in a position of extension.
The basic functional movement of tensor fasciae latae is walking. The tensor fasciae latae is heavily utilized in horse riding, hurdling and water skiing. Some problems that arise when this muscle is tight or shortened are pelvic imbalances that lead to pain in hips, as well as pain in the lower back and lateral area of knees.
Because of its insertion point on the lateral condyle of the tibia, it also aids in the lateral rotation of the tibia. This lateral rotation may be initiated in conjunction with hip abduction and medial rotation of the femur while kicking a soccer ball. The tensor fasciae latae works in synergy with the gluteus medius and
gluteus minimus
The gluteus minimus, or glutæus minimus, the smallest of the three gluteal muscles, is situated immediately beneath the gluteus medius.
Structure
It is fan-shaped, arising from the outer surface of the ilium, between the anterior and infer ...
muscles to abduct and medially rotate the femur.
The TFL is a hip abductor muscle. To stretch the tensor fasciae latae, the knee may be brought medially across the body (adducted). If one leans against a wall with crossed legs (externally/laterally rotated hips) and pushes the pelvis away from the wall (leaning the upper body towards it) sidebending the lumbar spine (i.e.: curving the spine to the side) should be avoided as it stretches the lumbar region rather than the tensor fasciae latae and other muscles which cross the hip rather than the spine.
Clinical significance
Because it is used for so many movements and is in a shortened position when seated, the TFL becomes tight easily. TFL stretches lengthen this important muscle.
Strain
A small case notes that “it seems possible that a sloped or banked surface could predispose an individual to a TFL strain.”
[Case Studies:Jonathan M. Cooperman, Journal of Orthopaedic & Sports Physical Therapy 1984 5:4, 201-203, DOI]
10.2519/jospt.1984.5.4.201
/ref> In such a case, “treatment usually consists of rest, heat, and flexibility exercises”, such as lliotibial band stretching.
Etymology
"Tensor fasciae latae" translates from Latin to English as "stretcher of the side band". "Tensor" is an agent noun that comes from the past participle stem "tens-" of the Latin verb "tendere", meaning "to stretch". "Fasciae" is the Latin term for "of the band" and is in the singular genitive case. "Latae" is the respective singular, genitive, feminine form of the Latin adjective "latus" meaning "side".
Additional images
Image:Gray430.png, Muscles of the pelvis and upper leg, showing the tensor fasciae latae at the middle left.
Image:Gray1238.png, Front of the right thigh, with the position of the tensor fasciae latae indicated.
Image:Gray1239.png, Back of the left thigh, with the position of the tensor fasciae latae indicated.
File:Anatomical dissection5.JPG, Tensor fasciae latae muscle
File:Slide4A.JPG, Tensor fasciae latae muscle
References
External links
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{{Authority control
Hip abductors
Hip flexors
Thigh muscles
Muscles of the lower limb
Muscles of the gluteus