Lecture 8: Muslces Of The Lower Extremities

Question 1

What is the only quadriceps muscle that does hip flexion?

Answer 1

Rectus femoris

Question 2

What is the origin, insertion, and action of the Sartorius muscle?

Answer 2

O: ASIS (Anterior Sup. Iliac Spine)
I: Medial aspect of proximal tibia
A: Flexes, Abducts, and laterally rotates thigh, flexes leg

Question 3

What are all the muscles of the quadriceps group?

Answer 3

Rectus femoris, Vastus lateralis, Vastus intermedius, Vastus medialis

Question 4

What is the origin, insertion, and action of the Rectus femoris muscle?

Answer 4

O: AIIF (Anterior Inf. Iliac Spine), superior margin of acetabulum
I: patella and tibial tuberosity
A: Extends leg and flexes thigh

Question 5

What is the origin, insertion, and action of the Vastus lateralis muscle?

Answer 5

O: greater trochanter, intertrochanteric line, linea aspera
I: same as Rectus femoris
A: Extends leg and flexes thigh

Question 6

What is the origin, insertion, and action of the Vastus intermedius muscle?

Answer 6

O: anterior and lateral surfaces of the shaft of the femur (proximal)
I: same as Rectus femoris
A: Extends leg

Question 7

What is the origin, insertion, and action of the Vastus medialis muscle?

Answer 7

O: linea aspera, medial supracondylar line, intertrochanteric line
I: same as Rectus femoris
A: Extends leg (same as intermedius)

Question 8

What are all the 2 major important muscles part of the Iliopsoas group?

Answer 8

1) Iliacus muscle
2) Psoas major muscle (minor is not that important)

Question 9

a) What group does the Iliacus muscle belong to?
b) What is the origin, insertion, and action of this muscle

Answer 9

a) The Iliopsoas group
b) O: Iliac fossa, ala of sacrum
I: lesser trochanter
A: Flexes thigh at hip joint (prime mover in thigh flexion), flexes trunk

Question 10

What are all the 10 hip flexor muscles?

Answer 10

1) The 3 Iliopsoas muscles
2) Rectus fermoris
3) Sartorius
4) Pactineus
5) Gracilis
6) The Adductor muscles (Longus and Magnus)

Question 11

a) What group does the Psoas major muscle belong to?
b) What is the origin, insertion, and action of this muscle

Answer 11

a) The Iliopsoas group
b) O: Transverse processes, bodies and discs of lumbar vertebrae
I: same as Iliacus (lesser trochanter)
A: Major flexor of the hip joint

Question 12

What is the origin, insertion, and actions of this muscle of the Tensor Fasciae Latae?

Answer 12

O: ASIS
I: Iliotibial tract
A: Flexes leg, Abducts thigh, Medially rotates the thigh

Question 13

What is the origin, insertion, and actions of the Pectineus muscle?

Answer 13

O: Pectineal line of pubis and superior ramus
I: A line from lesser trochanter to linea aspera
A: Adducts, flexes and medially rotates thigh

Question 14

What are the three Adductor muscles?

Answer 14

Adductor Longus, Adductor Brevis and Adductor Magnus

Question 15

What is the origin, insertion, and actions of the Gracilis?

Answer 15

O: Body of pubis, inferior pubic ramus and ischial ramus
I: medial surface of tibia
A: Adducts thigh, flexes and and medially rotates LEG

Question 16

What is the origin, insertion, and actions of the Adductor Longus ?

Answer 16

O: Near pubic symphysis
I: Linea aspera
A: Same as Pectineus ( Adducts, flexes and medially rotates thigh)

Question 17

What is the origin, insertion, and actions of the Adductor Brevis ?

Answer 17

O: Body and Inferior ramus of pubis
I: Linea aspera
A: Adducts and medially rotates thigh

Question 18

What is the origin, insertion, and actions of the Adductor Magnus ?

Answer 18

O: Ischial and pubic rami and ischial tuberosity
I: Linea aspera, supracondylar line, and it’s the only one that inserts in the adductor tubercle of femur
A: Same as Adductor Longus and also works with the hamstrings in thigh extension

Question 19

a) What are does the hamstring group muscles consist of?
b) What action do they all have in common?

Answer 19

a) Biceps femoris, Semitendinosus, Semimembranosus
b) They all extend the thigh and flex the leg

Question 20

What is the origin and insertion of the Biceps femoris

Answer 20

O: Ischial tuberosity, linea astera
I: Head of fibula and lateral condyle of tibia

Question 21

What is the origin and insertion of the Semitendinosus

Answer 21

O: Ischial tuberosity
I: Medial aspect of the upper tibial shaft

Question 22

What is the origin and insertion of the Semimembranosus

Answer 22

O: Same as Semitendinosus (Ischial tuberosity)
I: medial condyle of the tibia

Question 23

What is the origin, insertion and action of the Gluteus Maximus

Answer 23

O: Dorsal ilium, sacrum, and coccyx
I: gluteal tuberosity on the femur, iliotibial tract
A:Major extensor of the thigh

Question 24

What is the origin, insertion and action of the Gluteus Medius

Answer 24

O: Between anterior and posterior gluteal lines of the ilium
I: lateral aspect of greater trochanter
A: Abducts and medially rotates thigh

Question 25

What is the origin, insertion and action of the Gluteus Minimus

Answer 25

O: Between anterior and inferior gluteal lines of the ilium
I: anterior border of greater trochanter
A: Same as gluteus medius (Abducts and medially rotates thigh)

Question 26

What is the origin, insertion and action of the Piriformis?

Answer 26

O: anterolateral surface of the sacrum
I: superior border of greater trochanter
A: Rotates extended thigh laterally

Question 27

What action do both the Gastrocnemius and the Soleus do?

Answer 27

Both plantar flexes the foot

Question 28

What is the origin and insertion of the Gastrocnemius?

Answer 28

O: by two heads from medial and lateral condyles of femur
I: Posterior calcaneus (through a calcaneal tendon)

Question 29

What is the origin and insertion of the Soleus?

Answer 29

O: Extensive cone-shaped origin from superior tibia, fibula and interosseous membrane
I: Same as the Gastrocnemius (Posterior calcaneus)