Gluteal And Thigh Muscles

Question 0

Gluteus medius Origin? Insertion? Innervation? Action?

Answer 0

O: External surface of ilium between anterior and posterior gluteal lines

I: Lateral surface of greater trochanter of femur

Inner: Superior gluteal nerve (L4, L5, S1)

Action: Abduct and medially rotate thigh; keep pelvis level when opposite leg is raised

Question 1

Gluteus maximus Origin? Insertion? Innervation? Action?

Answer 1

O: Ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; and sacrotuberous ligament

I: Most fibers end in iliotibial tract, which inserts into lateral condyle of tibia; some fibers insert on gluteal tuberosity of femur

Inner: Inferior gluteal nerve (L5, S1, S2)

Action: Extends thigh and assists in its lateral rotation; steadies thigh and assists in rising from siting position

Question 2

Gluteus minimus Origin? Insertion? Innervation? Action?

Answer 2

O: External surface of ilium between anterior and inferior gluteal lines

I: Anterior surface of greater trochanter of femur

Inner: Superior gluteal nerve (L4, L5, S1)

Action: Abduct and medially rotate thigh; keep pelvis level when opposite leg is raised

Question 3

Tensor fasciae latae Origin? Insertion? Innervation? Action?

Answer 3

O: Anterior superior iliac spine; anterior part of iliac crest

I: Iliotibial tract, which attaches to lateral condyle of tibia (Gerdy tubercle)

Inner: Superior gluteal nerve (L4, L5, S1)

Action: Flexes thigh

Question 4

Piriformis Origin? Insertion? Innervation? Action?

Answer 4

O: Anterior surface of 2-4th sacral segments; superior margin of greater sciatic notch and sacrotuberous ligament

I: Superior border of greater trochanter of femur

Inner: Branches of anterior rami of S1 and S2

Action: Laterally rotate extended thigh; abduct flexed thigh; steady femoral head in acetabulum

Question 5

Obturator internus Origin? Insertion? Innervation? Action?

Answer 5

O: Pelvic surface of ilium and ischium; obturator membrane

I: Medial surface of greater trochanter (trochanteric fossa) of femur

Inner: Nerve to obturator internus (L5 and S1)

Action: Laterally rotate extended thigh; abduct flexed thigh; steady femoral head in acetabulum

Question 6

Superior gemellus Origin? Insertion? Innervation? Action?

Answer 6

O: Ischial spine

I: Medial surface of greater trochanter (trochanteric fossa) of femur

Inner: Nerve to obturator internus (L5 and S1)

Action: Laterally rotate extended thigh; abduct flexed thigh; steady femoral head in acetabulum

Question 7

Inferior gemellus Origin? Insertion? Innervation? Action?

Answer 7

O: Ischial tuberosity

I: Medial surface of greater trochanter (trochanteric fossa) of femur

Inner: Nerve to quadratus femoris (L5 and S1)

Action: Laterally rotate extended thigh; abduct flexed thigh; steady femoral head in acetabulum

Question 8

Quadratus femoris Origin? Insertion? Innervation? Action?

Answer 8

O: Lateral border of ischial tuberosity

I: Quadrate tubercle on intertrochanteric crest of femur and area inferior to it

Inner: Nerve to quadratus femoris (L5 and S1)

Action: Laterally rotates thigh; steadies femoral head in acetabulum

Question 9

Semitendinosus Origin? Insertion? Innervation? Action?

Answer 9

O: Ischial tuberosity

I: Medial surface of superior part of tibia

Inner: Tibial division of sciatic nerve (L5, S1, S2)

Action: Extend thigh; flex leg and rotate it medially when knee is flexed; when thigh and leg are fixed; can extend trunk

Question 10

Semimembranosus Origin? Insertion? Innervation? Action?

Answer 10

O: Ischial tuberosity

I: Posterior part of medial condyle of tibia; reflected attachment forms oblique popliteal ligament (to lateral femoral condyle)

Inner: Tibial division of sciatic nerve (L5, S1, S2)

Action: Extend thigh; flex leg and rotate it medially when knee is flexed; when thigh and leg are flexed, can extend trunk

Question 11

Biceps femoris Origin? Insertion? Innervation? Action?

Answer 11

O: Long head-> ischial tuberosity Short head-> linea aspera and lateral supracondylar line of femur

I: Lateral side of head of fibula; tendon is split at this site by fibular collateral ligament of knee

Inner: Long head-> Tibial division of sciatic nerve (L5, S1, S2)
Short head-> Common fibular division of sciatic nerve (L5, S1, S2)

Action: Flexes leg and rotates it laterally when knee if flexed; extends thigh (e.g., when starting to walk)

Question 12

Pectineus Origin? Insertion? Innervation? Action?

Answer 12

O: Superior ramus of pubis

I: Pectineal line of femur, just inferior to lesser trochanter

Inner: Femoral nerve (L2-L3); may receive branch from obturator nerve

Action: Adducts and flexes thigh; assists with medial rotation of thigh

Question 13

Sartorius Origin? Insertion? Innervation? Action?

Answer 13

O: Anterior superior iliac spine and superior part of notch inferior to it

I: Superior part of medial surface of tibia

Inner: Femoral nerve (L2-L3)

Action: Flexes, abducts, and laterally rotates thigh at hip joint; flexes leg at knee joint

Question 14

Psoas major Origin? Insertion? Innervation? Action?

Answer 14

O: Sides of T12-L5 vertebrae and discs between them; transverse processes of all lumbar vertebrae

I: Lesser trochanter of femur

Inner: Anterior rami of lumbar nerves (L1-L3)

Action: Acting conjointly in flexing thigh at hip joint and stabilizing this joint; psoas major is also a postural muscle that helps control deviation of the trunk and is active during standing

Question 15

Iliacus Origin? Insertion? Innervation? Action?

Answer 15

O: Iliac crest, iliac fossa, ala of sacrum, and anterior sacroiliac ligaments

I: Tendon of psoas major, lesser trochanter and femur distal to it

Innervation: Femoral nerve (L2-L3)

Action: Acting conjointly in flexing thigh at hip joint and stabilizing this joint; psoas major is also a postural muscle that helps control deviation of the trunk and is active during standing

Question 16

Rectus femoris Origin? Insertion? Innervation? Action?

Answer 16

O: Anterior inferior iliac spine and ilium superior to acetabulum

I: Via common tendinous (quadriceps tendon) and independent attachments to base of patella; indirectly via patellar ligament to tibial tuberosity; medial and lateral vasti also attach to tibia and patella via aponeurosis (medial and lateral patellar retinacula)

Inner: Femoral nerve (L2-L4)

Action: Extends leg and knee joint; rectus femoris also steadies hip joint and helps iliopsoas flex thigh

Question 17

Vastus lateralis Origin? Insertion? Innervation? Action?

Answer 17

O: Greater trochanter and lateral lip of linea aspera

I: Via common tendinous (quadriceps tendon) and independent attachments to base of patella; indirectly via patellar ligament to tibial tuberosity; medial and lateral vasti also attach to tibia and patella via aponeurosis (medial and lateral patellar retinacula)

Inner: Femoral nerve (L2-L4)

Action: Extends leg and knee joint; rectus femoris also steadies hip joint and helps iliopsoas flex thigh

Question 18

Vastus medialis Origin? Insertion? Innervation? Action?

Answer 18

O: Intertrochanteric line and medial lip of linea aspera of femur

I: Via common tendinous (quadriceps tendon) and independent attachments to base of patella; indirectly via patellar ligament to tibial tuberosity; medial and lateral vasti also attach to tibia and patella via aponeurosis (medial and lateral patellar retinacula)

Inner: Femoral nerve (L2-L4)

Action: Extends leg and knee joint; rectus femoris also steadies hip joint and helps iliopsoas flex thigh

Question 19

Vastus intermedius Origin? Insertion? Innervation? Action?

Answer 19

O: Anterior and lateral surfaces of shaft of femur

I: Via common tendinous (quadriceps tendon) and independent attachments to base of patella; indirectly via patellar ligament to tibial tuberosity; medial and lateral vasti also attach to tibia and patella via aponeurosis (medial and lateral patellar retinacula)

Inner: Femoral nerve (L2-L4)

Action: Extends leg and knee joint; rectus femoris also steadies hip joint and helps iliopsoas flex thigh

Question 20

Adductor longus Origin? Insertion? Innervation? Action?

Answer 20

O: Body of pubis inferior to pubic crest

I: Middle third of linea aspera of femur

Inner: Obturator nerve (L2-L4)

Action: Adducts thigh

Question 21

Adductor brevis Origin? Insertion? Innervation? Action?

Answer 21

O: Body and inferior ramus of pubis

I: Pectineal line and proximal part of linea aspera of femur

Inner: Obturator nerve (L2-L4)

Action: Adducts thigh and to some extent flexes it

Question 22

Adductor magnus Origin? Insertion? Innervation? Action?

Answer 22

O: Adductor part-> Inferior ramus of pubis; ramus of ischium
Hamstring part-> Ischial tuberosity

I: Adductor part-> Gluteal tuberosity, linea aspera, medial supracondylar line
Hamstring part-> Adductor tubercle of femur

Inner: Adductor part-> Obturator nerve (L2-L4)
Hamstring part-> Tibial part of sciatic nerve (L4)

Action: Adducts thigh; its adductor part also flexes thigh, and its hamstring part extends it

Question 23

Gracilis Origin? Insertion? Innervation? Action?

Answer 23

O: Body and inferior ramus of pubis

I: Superior part of medial surface of tibia

Inner: Obturator nerve (L2-L3)

Action: Adducts thigh; flexes leg, and helps rotate it medially

Question 24

Obturator externus Origin? Insertion? Innervation? Action?

Answer 24

O: Margins of obturator foramen and obturator membrane

I: Trochanteric fossa of femur

Inner: Obturator nerve (L3-L4)

Action: Laterally rotates thigh; steadies head of femur in acetabulum