Muscles Acting on the Hip

Question 1

Adductor Brevis

Answer 1

Origin: inferior pubic ramus
Insertion: pectineal line and linea aspera (deep to the pectineus and adductor longus mm.)
Action: adducts, flexes, and medially rotates the femur
Innervation: anterior division of the obturator nerve
Notes: anterior and posterior divisions of the obturator nerve lie on the anterior and posterior surfaces of adductor brevis

Question 2

Adductor Longus

Answer 2

Origin: medial portion of the superior pubic ramus
Insertion: linea aspera of the femur
Action: adducts, flexes, and medially rotates the femur
Innervation: anterior division of the obturator nerve
Notes: the most anterior of the adductor group of muscles

Question 3

Adductor Magnus

Answer 3

Origin: ischiopubic ramus and ischial tuberosity
Insertion: linea aspera of the femur; the ischiocondylar part inserts on the adductor tubercle of the femur
Action: adducts, flexes, and medially rotates the femur; extends the femur (ischiocondylar part)
Innervation: posterior division of the obturator nerve; tibial nerve (ischiocondylar part)
Notes: the ischiocondylar part of adductor magnus is a hamstring muscle by embryonic origin and action, so it is innervated by the tibial nerve

Question 4

Biceps Femoris

Answer 4

Origin: long head: ischial tuberosity; short head: lateral lip of the linea aspera
Insertion: head of fibula and lateral condyle of the tibia
Action: extends the thigh, flexes the leg
Innervation: long head: tibial nerve; short head: common fibular (peroneal) nerve
Notes: one of the “hamstring” muscles

Question 5

Gemellus, Inferior

Answer 5

Origin: ischial tuberosity
Insertion: obturator internus tendon
Action: laterally rotates the femur
Innervation: nerve to the quadratus femoris m.
Notes: gemellus is a Latin word that means “little twin”

Question 6

Gemellus, Superior

Answer 6

Origin: ischial spine
Insertion: obturator internus tendon
Action: laterally rotates the femur
Innervation: nerve to the obturator internus m.
Notes: gemellus is a Latin word that means “little twin”

Question 7

Gluteus Maximus

Answer 7

Origin: posterior gluteal line, posterior surface of sacrum and coccyx, sacrotuberous ligament
Insertion: upper fibers: iliotibial tract; lowermost fibers: gluteal tuberosity of the femur
Action: extends the thigh; laterally rotates the femur
Innervation: inferior gluteal nerve
Notes: gluteus maximus is a site of intramuscular injection

Question 8

Gluteus Medius

Answer 8

Origin: external surface of the ilium between the posterior and anterior gluteal lines
Insertion: greater trochanter of the femur
Action: abducts the femur; medially rotates the thigh
Innervation: superior gluteal nerve
Notes: the angle at which the gluteus medius tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation

Question 9

Gluteus Minimus

Answer 9

Origin: external surface of the ilium between the anterior and inferior gluteal lines
Insertion: greater trochanter of the femur
Action: abducts the femur; medially rotates the thigh
Innervation: superior gluteal nerve
Notes: the angle at which the gluteus minimus tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation

Question 10

Obturator Externus

Answer 10

Origin: the external surface of the obturator membrane and the superior and inferior pubic rami
Insertion: trochanteric fossa of the femur
Action: laterally rotates the thigh
Innervation: obturator nerve
Notes: the tendon of the obturator externus m. passes inferior to the neck of the femur to reach its insertion site

Question 11

Obturator Internus

Answer 11

Origin: the internal surface of the obturator membrane and margin of the obturator foramen
Insertion: greater trochanter on its medial surface above the trochanteric fossa
Action: laterally rotates and abducts the thigh
Innervation: nerve to the obturator internus m.
Notes: the obturator internus m. leaves the pelvis by passing through the lesser sciatic foramen; the superior and inferior gemellus mm. insert on the obturator internus tendon

Question 12

Pectineus

Answer 12

Origin: pecten of the pubis
Insertion: pectineal line of the femur
Action: adducts, flexes, and medially rotates the thigh
Innervation: femoral nerve and possibly the anterior division of the obturator nerve
Notes: pectineus often has a dual innervation

Question 13

Piriformis

Answer 13

Origin: anterior surface of sacrum
Insertion: upper border of greater trochanter of femur
Action: laterally rotates and abducts thigh
Innervation: ventral rami of S1-S2
Notes: piriformis leaves the pelvis by passing through the greater sciatic foramen

Question 14

Psoas Major

Answer 14

Origin: bodies and transverse processes of lumbar vertebrae
Insertion: lesser trochanter of femur (with iliacus) via iliopsoas tendon
Action: flexes the thigh; flexes & laterally bends the lumbar vertebral column
Innervation: branches of the ventral primary rami of spinal nerves L2-L4
Notes: the genitofemoral nerve pierces the anterior surface of the psoas major m.(Latin, psoas = the muscles of the loins)

Question 15

Psoas Minor

Answer 15

Origin: bodies of the T12 & L1 vertebrae
Insertion: iliopubic eminence at the line of junction of the ilium and the superior pubic ramus
Action: flexes & laterally bends the lumbar vertebral column
Innervation: branches of the ventral primary rams of spinal nerves L1-L2
Notes: absent in 40% of cases(Latin, psoas = the muscles of the loins)

Question 16

Quadratus Femoris

Answer 16

Origin: lateral border of the ischial tuberosity
Insertion: quadrate line of the femur below the intertrochanteric crest
Action: laterally rotates the thigh
Innervation: nerve to the quadratus femoris m.
Notes: the nerve to the quadratus femoris m. also innervates the inferior gemellus m.

Question 17

Rectus Femoris

Answer 17

Origin: straight head: anterior inferior iliac spine; reflected head: above the superior rim of the acetabulum
Insertion: patella and tibial tuberosity (via the patellar ligament)
Action: extends the leg, flexes the thigh
Innervation: femoral nerve
Notes: rectus femoris is part of the quadriceps femoris muscle

Question 18

Sartorius

Answer 18

Origin: anterior superior iliac spine
Insertion: medial surface of the tibia (pes anserinus)
Action: flexes, abducts and laterally rotates the thigh; flexes leg
Innervation: femoral nerve
Notes: its actions put the lower limb in the traditional cross-legged seated position of a tailor(Latin, sartorius = tailor)

Question 19

Semimembranosus

Answer 19

Origin: upper, outer surface of the ischial tuberosity
Insertion: medial condyle of the tibia
Action: extends the thigh, flexes the leg
Innervation: tibial nerve
Notes: one of the “hamstring” muscles

Question 20

Semitendinosus

Answer 20

Origin: lower, medial surface of ischial tuberosity (common tendon with biceps femoris m.)
Insertion: medial surface of tibia (via pes anserinus)
Action: extends the thigh, flexes the leg
Innervation: tibial nerve
Notes: pes anserinus is the common insertion for the gracilis, sartorius, and semitendinosus mm.

Question 21

Tensor Fasciae Latae

Answer 21

Origin: anterior part of the iliac crest, anterior superior iliac spine
Insertion: iliotibial tract
Action: flexes, abducts, and medially rotates the thigh
Innervation: superior gluteal nerve
Notes: tensor fascia latae redirects the rotational forces of the gluteus maximus m.