Tensor fasciae latae

Pronunciation: TEN-sor FASH-ee-ee LAY-tee

Structure & function

Location

A small muscle at the front-outer point of the hip, feeding into the long iliotibial (IT) band that runs down the outside of the thigh.

Origin

Anterior superior iliac spine (ASIS) and the iliac crest.

Insertion

Iliotibial (IT) band, which continues to the outer shin bone (tibia).

Main action(s)

Flexes, internally rotates, and abducts the thigh at the hip; tenses the IT band, helping stabilize the knee and pelvis during walking and running.

Joint(s) crossed

Hip joint (and indirectly the knee, via the IT band)

Movement plane

multiple

Innervation

Superior gluteal nerve (L4–S1)

In daily movement

Stabilizing the pelvis and knee during the stance phase of walking and running.

In exercise

Assists in hip-abduction and hip-flexion exercises; commonly discussed in runners for its role in IT-band tension.

Commonly confused with

Its abduction role is often credited entirely to the gluteus medius; in reality the two act together on the outside of the hip.

Common misconceptions

IT-band discomfort is not caused by the IT band itself 'snapping' — training approaches typically address hip and glute strength/control rather than trying to 'stretch' the band directly.