Lower Limb Muscles: Gluteal, Thigh and Adductor Anatomy

I) Muscles of the Gluteal Region

1) Deep Level

a) Gluteus minimus: the smallest of the gluteal muscles. It originates on the iliac fossa and inserts on the greater trochanter of the femur. Its function is to abduct and medially rotate the thigh.
Innervation: superior gluteal nerve.

b) Piriformis: located below the gluteus minimus. Its function is to laterally rotate and abduct the thigh.

c) Obturator internus: originates in the pelvic cavity, on the medial face of the obturator membrane, and inserts on the greater trochanter. Its function is to laterally rotate and abduct the thigh.

d) Superior and inferior gemelli: run along the extrapelvic borders of the obturator internus tendon and share the same action.

e) Obturator externus: inserts in the obturator foramen and the trochanteric fossa of the femur. It is the largest lateral rotator of the thigh.

f) Quadratus femoris: a quadrilateral muscle that extends from the ischial tuberosity to the femur. Its function is to laterally rotate the thigh.

2) Intermediate Plane

a) Gluteus medius: originates on the iliac fossa and inserts on the lateral surface of the greater trochanter. It abducts and medially rotates the thigh.
Innervation: superior gluteal nerve.

3) Superficial Plane

a) Gluteus maximus: originates on the sacrum and iliac crest and inserts on the femur. Its action is to extend and laterally rotate the thigh.

b) Tensor fasciae latae: a thin and superficial muscle that originates on the hip and inserts on the iliotibial tract, acting as an extensor of the leg.

II) Muscles of the Thigh

1) Anterior Group

a) Quadriceps femoris: wraps around almost the entire anterior femur. It is formed by four muscles whose tendons unite into a single tendon that inserts on the patella:

• Vastus lateralis
• Vastus medialis
• Rectus femoris: stabilized at the hip joint.
• Vastus intermedius

Innervation: femoral nerve. It extends the leg at the knee joint. Its distal insertion is at the patella and tibial tuberosity.

b) Sartorius: originates at the anterosuperior iliac spine and inserts on the tibia at the tibial tuberosity. Innervation: femoral nerve. It flexes, abducts and laterally rotates the thigh and flexes the knee joint.

2) Medial Group

a) Adductor magnus: part of the femur originates on the ischium and pubis. It adducts and flexes the thigh.

b) Adductor longus: located below the femur and originates on the pubic crest. It adducts the thigh. Innervation: obturator nerve.

c) Adductor brevis: its body branches to the inferior femur and the pubis. Innervation: obturator nerve. It adducts the thigh.

d) Obturator externus: goes to the obturator fossa and the membrane of the femur, acting as a trochanteric rotator.

e) Gracilis: inserts on the medial tibia below the pubis and acts as an adductor and flexor of the leg. Innervation: obturator nerve.