Gluteal region & posterior compartment of the thigh

Question 1

what are the important ‘landmarks’ of the ilium bone?

Answer 1

-ASIS (anterior superior)
-AIIS (anterior inferior)
-PSIS
-PIIS
-iliac crest
-gluteal lines - posterior, anterior and inferior

Question 2

what are the main landmarks of the pubis bone?

Answer 2

• the pubic symphysis
  -the superior ramus and inferior ramus

Question 3

what are the main landmarks of the ischium?

Answer 3

-the ischial tuberosity and spine
-greater sciatic notch
-lesser sciatic notch

Question 4

what is the difference between the intertrochanteric line and the intertrochanteric crest?

Answer 4

-intertrochanteric line marks the boundary between the femoral neck and the shaft ANTERIOLY
-the intertrochanteric crest marks the same boundary but POSTERIORLY

Question 5

what are the 3 gluteus muscles?

Answer 5

-gluteus maximus
-gluteus minimus
-gluteus medius

Question 6

what are the deep rotator muscles in the gluteal region?

Answer 6

• the piriformis
  -the obturator internus

Question 7

where is the gluteal region located?

Answer 7

• behind the pelvis and between the iliac crest and the gluteal fold

Question 8

describe the origin and insertion of the gluteus maximus

Answer 8

-it originates on the ilium (posterior to the posterior gluteal line), the sacrum and the sacrotuberous ligament
- 3/4 of the GM inserts onto the iliotibial tract and 1/4 inserts itself onto the gluteal tuberosity (femur)

Question 9

what are the main actions / functions of the gluteus maximus?

Answer 9

• hip extension (lying on belly and lifting leg up)
  -lateral rotation

Question 10

what nerve is the gluteus maximus innervated by?

Answer 10

the inferior gluteal nerve

Question 11

what is the origin and insertion of the gluteus medius?

Answer 11

-originates from the posterior and anterior gluteal lines
-inserts onto the gluteal tuberosity of the femur

Question 12

what is the origin and the insertion of the gluteus minimus?

Answer 12

-originates from the anterior and inferior gluteal lines
-inserts onto the gluteal tuberosity (femur)

Question 13

what nerve innervates both the gluteus medius and minimus?

Answer 13

the superior gluteal nerve

Question 14

what are the main actions of the gluteus medius and minimus?

Answer 14

• hip abduction & medial rotation

Question 15

Describe the trendelenburg gait

Answer 15

• it is an abnormal gait
• results from weakness of the abductor muscles (glut min and med) which causes the drooping of the pelvis to the contralateral side while walking

Question 16

where does the piriformis muscle originate from and where does it insert onto?

Answer 16

• originates from the anterior sacrum
  -exits the greater sciatic foramen
  -inserts into the greater trochanter

Question 17

what are the main actions of the piriformis muscle?

Answer 17

-lateral rotation
-acts to stabilise the hip joint

Question 18

why is the piriformis muscle an important landmark?

Answer 18

• as various other structures exit the greater sciatic foramen above or below the piriformis muscle

Question 19

where does the obturator internus muscle originate and insert onto?

Answer 19

• originates from the internal aspect of the obturator membrane
  -exits the lesser sciatic foramen
  -inserts into the greater trochanter (of femur)

Question 20

what are the main actions / functions of the obturator internus muscle?

Answer 20

• lateral rotation
  -stabilises the hip joint

Question 21

where does the sciatic nerve originate from?

Answer 21

the sacral plexus

Question 22

what nerve innervates the piriformis muscle?

Answer 22

nerve to piriformis

Question 23

what nerve innervates the obturator internus muscle?

Answer 23

nerve to obturator internus

Question 24

what is the motor function of the sciatic nerve?

Answer 24

• provides a direct motor supply for the muscles of the posterior thigh via small muscular branches

Question 25

what other nerves does the sciatic nerve divide into?

Answer 25

- the tibial nerve - provides motor supply to the posterior portion of leg and foot - the common perineal nerve - supplies motor function to the anterior and lateral muscles of the leg

Question 26

how does the sciatic nerve exit the pelvis?

Answer 26

- through the greater sciatic foramen, **below the piriformis**

Question 27

what is the sacral plexus?

Answer 27

a **nerve network **composed of the **anterior rami of the spinal nerves L4-L5 **(lumbosacral trunk) and** spinal nerves S1-S3**

Question 28

what are examples of branches of the sacral plexus that are associated with the posterior region of the thigh?

Answer 28

- superior gluteal nerve -inferior gluteal nerve -posterior cutaneous nerve of the thigh -nerves to the obturator internus and the quadrates femoris -pudenal nerve

Question 29

what muscles does the superior gluteal nerve supply?

Answer 29

- gluteus medius and minimus - tensor fascia lata

Question 30

what muscle does the inferior gluteal nerve supply?

Answer 30

the gluteus maximus

Question 31

what is the pudenal nerve?

Answer 31

a **mixed nerve** in charge of the motor and sensory supply of the **perineum and external genitalia in both sexes**

Question 32

how does the superior gluteal nerve exit the pelvis?

Answer 32

through the greater sciatic foramen, above the piriformis muscle

Question 33

where does the pudenal nerve exit and enter?

Answer 33

- enter lesser sciatic foramen -exits the greater sciatic foramen below the piriformis muscle

Question 34

how does the inferior gluteal nerve exit the pelvis?

Answer 34

* through the greater sciatic foramen, **below** the piriformis

Question 35

what are the branches of the internal iliac vessel?

Answer 35

-the superior gluteal (vein and artery) -the inferior gluteal (vein and artery)

Question 36

what are the boundaries of the greater sciatic foramen?

Answer 36

- the greater sciatic notch -the sacrospinous & sacrotuberous ligaments

Question 37

what are the main structures in the greater sciatic foramen?

Answer 37

- piriformis muscle -sciatic nerve -superior & inferior gluteal nerve and vessels -pudenal nerve -posterior cuteanous nerve of the thigh

Question 38

what are the 3 hamstring muscles ?

Answer 38

-semitendinosis -semimembranosis -long head of biceps femoris

Question 39

where does the semitendinosis muscle originate and insert onto?

Answer 39

- originates from the ischial tuberosity -attaches onto the pes anserinus (goose foot on tibia)

Question 40

describe how the semitendinosis muscle is superiorly and inferiorly?

Answer 40

- muscular superiorly -tendinous inferiorly

Question 41

what is the origin and insertion of the semimembranosis muscle?

Answer 41

- originates from the ischial tuberosity -attaches onto the superomedial tibia

Question 42

describe how the semimembranosis muscle is superiorly and inferiorly

Answer 42

-membranous superiorly -muscular inferiorly

Question 43

what are the medial hamstring muscles?

Answer 43

- the semitendinosis and the semimembranosis

Question 44

what is the lateral hamstring muscle?

Answer 44

- the biceps femoris

Question 45

what are the functions of the medial muscles of the hamstring (semitendinosis and semimembranosis)?

Answer 45

- to extend hip -flex and rotate knee

Question 46

where does the long head and short head originate from?

Answer 46

- long head originates from the ischial tuberosity -short head originates from the lines aspera of femur

Question 47

where do both heads of the biceps femoris insert onto?

Answer 47

- the head of the fibula

Question 48

what are the functions of the biceps femoris muscle?

Answer 48

- to extend the hip -flex and rotate knee

Question 49

what branch of the sciatic nerve supplies the hamstring muscles except for the short head of the bicep femoris muscle?

Answer 49

the tibial nerve

Question 50

what branch of the sciatic nerve supplies the short head of the biceps femoris muscle?

Answer 50

common peroneal/ fibular nerve