Tensor Fasciae Latae (TFL) Muscle Anatomy

Overview
Origin Anterior superior iliac spine (ASIS)
Anterior aspect of the iliac crest
Insertion Fascia of the iliotibial tract
The iliotibial tract inserts onto the iliotibial tubercle (also known as Gerdy’s tubercle)
Action Stabilisation of the hip and knee
Hip abduction
Hip internal rotation
Weak hip flexion
Knee flexion past 30 degrees
Lateral rotation at the tibia
Nerve Superior gluteal nerve (L4, L5, S1)
Artery Deep branch of the superior gluteal artery

Location & Overview

The tensor fasciae latae (TFL) is a muscle located in the proximal and anterolateral aspect of the thigh. It sits between the deep and superficial fibers of the iliotibial tract, also known as the iliotibial band (ITB). It belongs to the muscles of the gluteal region. Other muscles of this region are the gluteus maximus, gluteus medius and gluteus minimus [1] [2].

tensor fasciae latae muscle superficial view

Pictured here we can see the tensor fasciae latae amongst the other muscles of the thigh.

tensor fasciae latae and the iliotibial tract together

Pictured here we can see the tensor fasciae latae and the iliotibial tract together.

Origin & Insertion

The tensor fasciae latae originates from the anterior superior iliac spine (ASIS) and the anterior aspect of the iliac crest. As it passes down the thigh, it attaches to the deep and superficial fascia of the iliotibial band. Due to this, the insertion point for the tensor fasciae latae is the iliotibial band. Once the tensor fasciae latae inserts into the iliotibial band, the iliotibial band continues down the leg, where it eventually crosses the knee joint and inserts onto the iliotibial tubercle (also known as Gerdy’s tubercle) [3] [4] [5].

origin point of the tensor fasciae latae on the anterior superior iliac spine

Highlighted in red, we can see the origin point of the tensor fasciae latae on the anterior superior iliac spine (ASIS) and the anterior aspect of the iliac crest.

tensor fasciae latae insertion on the fascia of the iliotibial tract

Highlighted in blue we can see the insertion point of the tensor fasciae latae on the fascia of the iliotibial tract.

iliotibial tract inserting onto the iliotibial tubercle

Highlighted in blue we can see the insertion point of the iliotibial tract. The tensor fasciae latae inserts into the iliotibial tract and therefore by proxy has a connection to the same insertion point. The iliotibial tract inserts onto the iliotibial tubercle (also known as Gerdy’s tubercle).

Actions

The TFL assists various muscles groups in the stabilisation and movement of the hip and knee joints. For example, it works with the gluteus medius and gluteus minimus during internal rotation and abduction of the hip. Both the gluteus maximus and TFL connect via an aponeurosis to the iliotibial tract and due to this the TFL is also able to work with the gluteus maximus to abduct the hip. In addition to abduction, it can also assist with flexion of the hip. However, the hip flexion the TFL provides is weak comparative to primary hip flexors, such as the rectus femoris and iliopsoas muscle group [6] [7].

The TFL connects into the iliotibial tract via an aponeurosis. The iliotibial tract then inserts onto the iliotibial tubercle (also known as Gerdy’s tubercle). Due to this, contraction of the TFL can contribute to flexion of the knee joint (because the iliotibial tract crosses the knee joint). However, the TFL can only contribute to knee flexion beyond approximately 30 degrees. This connection of the TFL to the tibia via the iliotibial tract is how it can assist in stabilisation of the knee joint. The TFL can also act on the iliotibial tract to assist in lateral rotation of the tibia [8] [9].

A function of the TFL is to assist in walking. When the TFL contracts it weakly pulls the ilium inferiorly (hip abduction). This contraction then assists in lifting the hip on the opposite side. This is particularly useful when walking because during the swing phase of gait, it allows the leg to swing through without hitting the ground [10] [11].

Innervation

The TFL is innervated by the superior gluteal nerve (L4, L5, S1) which is a branch of the sacral plexus [12].

Blood Supply

Blood is supplied to the TFL via the deep branch of the superior gluteal artery [13].

Want some flashcards to help you remember this information? Then click the link below:
Tensor Fasciae Latae Flashcards

References

References
1, 3, 6, 8, 10, 12, 13 Trammell AP, Nahian A, Pilson H. Anatomy, Bony Pelvis and Lower Limb, Tensor Fasciae Latae Muscle. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499870/
2, 5, 7, 9, 11 Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017
4 Hyland S, Graefe SB, Varacallo M. Anatomy, Bony Pelvis and Lower Limb, Iliotibial Band (Tract) [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537097/