Thigh Muscles

Question 1

What are muscles are in the posterior compartment of the thigh

Answer 1

Biceps femoris
Semitendinosus
Semimembranosus

Question 2

Biceps Femoris

origin, insertion, action

Answer 2

Origin - 2 heads
Long head - Ischial tuberosity
Short head - linea aspera and lateral supracondylar line of femur
Insertion - fibular head
Action - Extends thigh, flexes leg, laterally rotates leg while knee is flexed

Question 3

Semitendinosus

origin, insertion, action

Answer 3

Origin - Ischial tuberosity
Insertion - Superior medial tibia (pes anserinus)
Action - Extends thigh, flexes leg, medially rotates leg wihle knee is flexed

Question 4

Semimembranosus

origin, insertion, action

Answer 4

Origin - Ischial tuberosity
Insertion - Tibia (medial condyle, posterior aspect)
Action - Extends thigh, flexes leg, medially rotates leg while knee is flexed

Question 5

What are the three main muscles in the anterior thigh compartment

Answer 5

Iliopsoas
Sartorius
Quadriceps Femoris

Question 6

Iliopsoas

origin, insertion, action

Answer 6

Origin - 2x muscle origins.
1. Iliacus - Iliac crest, iliac fossa, ala of sacrum, anterior sacroiliac ligament
2. Psoas Major - T12 - L5 vertebra sides (inc. IVD), transverse process of all Lx
Insertion -
1. Iliacus - inserts in psoas major tendon and lesser trochanter (femur)
2. Psoas major - inserts in lesser trochaner (femur)
Action - Flexion of thigh at hip joint, hip stability

Question 7

Sartorius

origin, insertion, action

Answer 7

Origin - Anterior superior iliac spine
Insertion - Superior medial tibia (pes anserinus)
Action - Flexion/abduction/external rotation of hip

Question 8

What muscles are grouped under quadratus femoris?

Answer 8

Rectus Femoris
Vastus lateralis
Vastus medialis
Vastus intermedius

Question 9

Quadratus femoris

origin, insertion, action

Answer 9

Origin:
Rectus femoris - anterior inferior iliac spine
Vastus lateralis - greater trochanter and lateral lip of linea aspera
Vastus medialis - intertrochanteric line and medial lip of linea aspera (femur)
Vastus intermedius - anterior and lateral shaft of femur
Insertion - tibial tuberosity via quadriceps tendon, each muscle idenpentantly attaches to the base of patella
Action - Extends leg at knee joint, quadratus femoris assists in hip flexion

Question 10

Name the medial thigh muscles

Answer 10

Adductor Longus
Adductor Brevis 
Adductor Magnus 
Gracilis
Obturator Externus

Question 11

Adductor Longus

origin, insertion, action

Answer 11

Origin - Body of pubis, inferior to pubic crest
Insertion - Middle 1/3 of linea aspera (femur)
Action - Adduction of thigh

Question 12

Adductor Brevis

origin, insertion, action

Answer 12

Origin - Body of pubis/inferior pubic ramus
Insertion - Pectineal line/proximal linea aspera\
Action - Adduction of thigh, mild flexion

Question 13

Adductor Magnus

origin, insertion, action

Answer 13

2 parts, adductor and hamstring
ADDUCTOR part
Origin - Inferior pubic ramus/ischial ramus
Insertion - Gluteal tuberosity, linea aspera, medial supracondylar line
Action - Adduction of thigh, some flexion
HAMSTRING part
Origin - Ischial tuberosity
Insertion - Adductor tubercle (femur)
Action - Extends thigh

Question 14

Gracilus

Answer 14

O - Body/inferior pubic ramus
I - Superior medial tibia (pes anserinus)
A - Adducts thigh, flexes leg

Question 15

Obturator Externus

Answer 15

Part of the medial compartment, but functions as a glute muscle
O - Margins of obturator foramen/obturator membrane
I - Trochanteric Fossa (femur)
A - Laterally rotates of extended thigh, abduction of flexed thigh