Muscles of the hip: the gluteal group, deep lateral rotators and tensor fasciae latae

The gluteal region sits behind the hip joint and contains two layers of muscle. The superficial group, gluteus maximus, gluteus medius, gluteus minimus and tensor fasciae latae, mainly abducts and extends the hip. The deep group, piriformis, obturator internus, the superior and inferior gemelli and quadratus femoris, mainly rotates the femur laterally. The deep muscles also steady the hip by pressing the head of the femur into the acetabulum (the hip socket). (TeachMeAnatomy: The Muscles of the Gluteal Region.)

Other muscles also cross the hip. OpenStax lists obturator externus with the lateral rotators, groups psoas major and iliacus together as iliopsoas, and describes the thigh as split by deep fascia into anterior, medial and posterior compartments. The medial (adductor) compartment pulls the thigh towards the midline, and the hamstrings at the back extend the thigh as well as bending the knee. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

Gluteus maximus is the largest of the gluteal muscles, gluteus medius lies deep to it, and gluteus minimus is the smallest of the three, lying deepest. Together the gluteal muscles are among the largest and most powerful muscles in the body. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

Gluteus maximus arises from the back of the ilium behind the posterior gluteal line, the posterior part of the iliac crest, the lower sacrum and coccyx, and the sacrotuberous ligament. Most of its fibres insert into the iliotibial band (iliotibial tract) of the fascia lata; the deeper lower fibres insert on the gluteal tuberosity on the back of the femur. (University of Washington Musculoskeletal Atlas: Gluteus maximus.)

It is the major extensor of the hip and assists lateral rotation of the thigh; its upper fibres also help to abduct. It is supplied by the inferior gluteal nerve (L5, S1, S2) and by the superior and inferior gluteal arteries, with a contribution from the first perforating branch of the profunda femoris (deep femoral) artery. (University of Washington Musculoskeletal Atlas: Gluteus maximus.)

TeachMeAnatomy notes that gluteus maximus is used mainly when force is needed, such as in running or climbing. The iliotibial tract it pulls on runs down the outside of the thigh and attaches to the lateral condyle of the tibia. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

Automatic page for the largest gluteal muscle in the 3D model. Gluteus maximus.

Gluteus medius arises from the outer (dorsal) surface of the ilium below the iliac crest and inserts on the lateral and superior surfaces of the greater trochanter of the femur. It is the major abductor of the thigh. Its anterior fibres help to rotate the hip medially, while its posterior fibres help to rotate it laterally. It is supplied by the superior gluteal nerve (L4, L5, S1) and the superior gluteal artery. (University of Washington Musculoskeletal Atlas: Gluteus medius.)

Gluteus minimus lies under gluteus medius. It arises from the ilium between the inferior and anterior gluteal lines and from the edge of the greater sciatic notch, and inserts on the anterior surface of the greater trochanter. It abducts and medially rotates the hip and shares the superior gluteal nerve and artery with gluteus medius. (University of Washington Musculoskeletal Atlas: Gluteus minimus.)

The most important everyday job of these two muscles is holding the pelvis level when you stand on one leg, as happens with every step. If the superior gluteal nerve is damaged, both are weakened and the pelvis becomes unstable during walking. In the Trendelenburg test the patient stands on each leg in turn; a positive result is a drop of the pelvis on the unsupported side, judged by comparing the two iliac crests. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

Automatic page for gluteus medius in the 3D model. Gluteus medius.

Tensor fasciae latae (often shortened to TFL, and sometimes spelled tensor fascia lata) is a small muscle at the front of the hip. It arises from the anterior superior iliac spine (ASIS), the outer lip of the front of the iliac crest and the fascia lata, and inserts into the iliotibial band. It is supplied by the superior gluteal nerve (L4, L5, S1) and by the superior gluteal and lateral circumflex femoral arteries. (University of Washington Musculoskeletal Atlas: Tensor fascia lata.)

By putting tension on the iliotibial band, TFL helps to stabilise both the hip and the knee. TeachMeAnatomy adds that it abducts and medially rotates the lower limb and supports the gait cycle. TeachMeAnatomy groups it with the superficial gluteal muscles even though it sits at the front of the hip, and like gluteus medius and minimus it is supplied by the superior gluteal nerve. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

OpenStax describes TFL as a thick, squarish muscle in the upper part of the lateral thigh that steadies the lateral side of the knee by making the iliotibial tract taut. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

Automatic page for the TFL muscle in the 3D model. Tensor fasciae latae.

Piriformis arises from the front (pelvic) surface of the sacrum and the margin of the greater sciatic notch, leaves the pelvis through the greater sciatic foramen and inserts on the superior border of the greater trochanter. It rotates the hip laterally and helps to abduct it when the hip is flexed. The University of Washington atlas gives its nerve as the nerve to piriformis (L5, S1, S2). (University of Washington Musculoskeletal Atlas: Piriformis.)

Obturator internus (the 'internus muscle' of the hip) arises from the inner surface of the obturator membrane and the bony margins of the obturator foramen, inside the pelvis. Its tendon leaves through the lesser sciatic foramen and inserts on the medial surface of the greater trochanter together with the two gemelli. It rotates the thigh laterally and helps abduct it when the hip is flexed, and is supplied by the nerve to obturator internus (L5, S1), a branch of the sacral plexus. (University of Washington Musculoskeletal Atlas: Obturator internus.)

The superior gemellus arises from the ischial spine and the inferior gemellus from the ischial tuberosity; both insert on the greater trochanter alongside the obturator internus tendon. The superior gemellus shares the nerve to obturator internus, while the inferior gemellus is supplied by the nerve to quadratus femoris. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

Quadratus femoris is a flat, square muscle below the gemelli. It arises from the lateral margin of the ischium just above the ischial tuberosity and inserts on the quadrate tubercle on the intertrochanteric crest of the femur. It rotates the hip laterally and helps to adduct it, and is supplied by the nerve to quadratus femoris and inferior gemellus (L5, S1). (University of Washington Musculoskeletal Atlas: Quadratus femoris.)

Obturator externus lies deeper and lower, on the outside of the pelvis. It arises from the outer surface of the obturator membrane and the surrounding bone, passes under the neck of the femur and inserts on the back of the greater trochanter. Unlike the other lateral rotators, it is supplied by the obturator nerve (L2 to L4), which is why it is often described with the medial compartment of the thigh. (TeachMeAnatomy: Muscles of the Medial Compartment of the Thigh.)

Automatic page for piriformis in the 3D model. Piriformis.

Piriformis is the key landmark of the buttock. It divides the gluteal region into upper and lower parts, and the nerves and vessels are named by whether they leave the pelvis above it (superior gluteal) or below it (inferior gluteal). The sciatic nerve normally passes directly below piriformis. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

This relationship varies. A meta-analysis of 44 cadaver studies (8,257 specimens) found the usual pattern, an undivided sciatic nerve passing below piriformis, in about 90% of cases. The most common variant, in about 8%, is a nerve that divides early so that the common fibular (peroneal) part passes through piriformis while the tibial part passes below it. The authors regard such variants as one cause of piriformis syndrome, in which the nerve is irritated in the buttock. (Poutoglidou F et al. Sciatic Nerve Variants and the Piriformis Muscle: A Systematic Review and Meta-Analysis. Cureus. 2020.)

External (lateral) rotation of the hip turns the thigh and the front of the knee outwards. OpenStax lists six muscles whose main job is lateral rotation of the femur: piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus and quadratus femoris. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

Several larger muscles help. Gluteus maximus assists lateral rotation, and the posterior fibres of gluteus medius rotate the hip laterally while its anterior fibres rotate it medially. (University of Washington Musculoskeletal Atlas: Gluteus medius.)

Iliacus, best known as a hip flexor, also helps to rotate the thigh externally. (Radiopaedia: Iliacus muscle.)

Sartorius, the long strap muscle on the front of the thigh, flexes and laterally rotates the hip as well as flexing the knee. (University of Washington Musculoskeletal Atlas: Sartorius.)

Internal (medial) rotation is the opposite movement. TeachMeAnatomy lists gluteus medius, gluteus minimus and tensor fasciae latae as medial rotators as well as abductors of the hip. (TeachMeAnatomy: The Muscles of the Gluteal Region.)

The main hip flexor is iliopsoas, formed by psoas major and iliacus. It runs from the lumbar spine and the inside of the pelvis, passes behind the inguinal ligament and in front of the hip joint, and inserts on the lesser trochanter of the femur. Kenhub calls it the largest and strongest of the inner hip muscles. (Kenhub: Iliopsoas muscle.)

Other muscles that flex the hip cross it from the front of the thigh: rectus femoris, sartorius and pectineus. Rectus femoris is the only part of quadriceps femoris that crosses both the hip and the knee. (TeachMeAnatomy: Muscles of the Anterior Compartment of the Thigh.)

The adductors, adductor longus, adductor brevis, adductor magnus and gracilis, lie in the medial compartment of the thigh and are supplied mainly by the obturator nerve (L2 to L4). The hamstring part of adductor magnus also extends the hip and is supplied by the tibial part of the sciatic nerve. (TeachMeAnatomy: Muscles of the Medial Compartment of the Thigh.)

Quadriceps, adductors and hamstrings: the three compartments of the thigh. Thigh muscles.

Gluteal tendinopathy, degeneration of the gluteus medius or gluteus minimus tendons where they insert on the greater trochanter, is described as the most common tendinopathy of the lower limb. It causes chronic pain and tenderness over the side of the hip, typically worse on walking, climbing stairs or lying on the affected side, and it typically affects women in their fourth to sixth decades of life. It is now recognised as the main cause of greater trochanteric pain syndrome, which was once blamed mainly on trochanteric bursitis. (Ladurner A, Fitzpatrick J, O'Donnell JM. Treatment of Gluteal Tendinopathy: A Systematic Review. Orthop J Sports Med. 2021.)

In external snapping hip, the iliotibial band slides over the greater trochanter as the hip moves from extension into flexion, producing a snap that is usually felt or seen rather than heard. Most cases settle with conservative care; when surgery is needed, options include endoscopic release of the iliotibial band or gluteus maximus. (Walker P et al. Snapping Hip Syndrome: A Comprehensive Update. Orthop Rev. 2021.)

Gemellus inferior

A small lateral rotator of the hip, below obturator internus.

Gemellus superior

A small lateral rotator of the hip, above obturator internus.

Gluteus maximus

The largest and most superficial buttock muscle.

Gluteus medius

A fan-shaped muscle under gluteus maximus on the outer ilium.

Gluteus minimus

The smallest and deepest gluteal muscle.

Obturator externus

A flat, fan-shaped deep muscle of the medial thigh that wraps behind the neck of the femur.

Obturator internus

A lateral rotator of the hip that arises inside the pelvis and leaves through the lesser sciatic foramen.

Piriformis

A pear-shaped lateral rotator of the hip that passes through the greater sciatic foramen.

Quadratus femoris

A flat quadrangular deep gluteal muscle below the inferior gemellus.

Tensor fasciae latae

A small hip muscle at the front and side of the thigh.