Posterior Lateral Muscles & External Rotators

Question 1

Tensor Fasciae Latae

Answer 1

Origin:
Anterior part of the iliac crest and the anterior superior iliac spine (ASIS).

Attachment:
Iliotibial tract (IT band).

Function:
It helps stabilize the pelvis and thigh, and it can also assist in hip flexion and abduction.

Blood Supply:
Internal Iliac Artery

Nerve Supply:
Innervated by the superior gluteal nerve.
anterior rami of L4-S1

Question 2

Gluteus Maximus

Answer 2

Origin:
Posterior part of the ilium, sacrum, and coccyx.

Attachment:
Gluteal tuberosity of the femur and the iliotibial band (IT band).

Function:
The largest and most superficial gluteal muscle, it’s the major extensor of the hip joint. It’s responsible for actions like standing up from a seated position, walking, and running.

Blood Supply:
Internal Iliac Artery

Nerve Supply:
Innervated by the inferior gluteal nerve.

Question 3

Gluteus Medius

Answer 3

Origin:
External surface of the ilium, between the anterior and posterior gluteal lines.

Attachment:
Greater trochanter of the femur.

Function:
It abducts and medially rotates the hip, playing a key role in maintaining hip stability, especially during activities like walking and standing on one leg.

Blood Supply:
Internal Iliac Artery

Nerve Supply:
Innervated by the superior gluteal nerve.

Question 4

Gluteus Minimus

Answer 4

Origin:
External surface of the ilium, between the anterior and inferior gluteal lines.

Attachment:
Greater trochanter of the femur.

Function:
Similar to the gluteus medius, it abducts and medially rotates the hip and is important for hip joint stability during walking and other movements.

Blood Supply:
Internal Iliac Artery

Nerve Supply:
Innervated by the superior gluteal nerve.

Question 5

Quadratus Femoris

Answer 5

Origin:
Ischial tuberosity (part of the pelvic bone).

Attachment:
Quadrate tubercle on the intertrochanteric crest of the femur.

Function:
Acts as a hip adductor and lateral rotator of the thigh.

Blood Supply:
Supplied by branches of femoral artery.

Nerve Supply:
Innervated by the nerve to quadratus femoris, a branch of the sacral plexus.

Question 6

Piriformis

Answer 6

Origin:
Arises from the anterior surface of the sacrum.

Attachment:
Inserts into the greater trochanter of femur.

Function:
Primarily functions as an external rotator of the hip joint, rotating the thigh away from the body. It also helps abduct the thigh and assists in stabilizing the hip joint.

Blood Supply:
Internal Iliac Artery

Nerve Supply:
Innervated by the sacral plexus, specifically spinal nerves S1 and S2.

Question 7

What is the ILIOTIBIAL TRACT?

Answer 7

The iliotibial tract, often referred to as the iliotibial band (IT band), is a tough, fibrous band of connective tissue in the thigh. It runs along the lateral (outer) aspect of the thigh and plays an important role in stabilizing the knee joint during movement.

extends from the iliac crest of the hip down to the tibia

muscles that attach to the iliotibial tract:

Tensor Fasciae Latae (TFL)
Gluteus Maximus
Vastus Lateralis
Biceps Femoris