Muscles of posterior thigh Flashcards Preview

Leg > Muscles of posterior thigh > Flashcards

Flashcards in Muscles of posterior thigh Deck (20):
1

semitendinosus

ischial tuberosity (sitting bone) --> medial surface of superior tibia
innervation: tibial division of sciatic nerve (L5, S1, S2)
action: extend thigh, flex leg, rotate medially when knee flexed, can extend upper trunk when thigh + leg flexed

2

what is the function of the posterior thigh muscles?

extensors of hip & flexors of knee

3

Name the muscles of the posterior thigh

semimembranosus
semitendinosus
biceps femoris

4

semimembranosus

ischial tuberosity --> posterior part of medial condyle of tibia
tibial division of sciatic nerve (L5, S1, S2)
extend thigh, medial rotation and flex leg when knee is flexed

5

biceps femoris (long head)

ischial tuberosity --> lateral side of head of fibula
innervation: tibial division of sciatic nerve (L5, S1, S2)
function: flex leg + rotate it laterally when knee is flexed, extend thigh

6

Biceps femoris (short head)

linea aspera & lateral supracondylar line of femur --> lateral side of head of fibula
Innervation: common fibular division of sciatic nerve (L5, S1, S2)
Action: flex leg & rotate laterally when knee is flexed, extend thigh

7

what separates the long and short head of biceps femoris?

fibular collateral ligament of knee

8

What are muscles of the posterior thigh collectively known as?

The hamstrings

9

Which nerve innervates the hamstrings and why?

sciatic nerve (L4-S3) as it descends through the thigh

10

Where are the tendons of the hamstring formed?

medially and laterally to the posterior knee

11

which of the hamstrings is most lateral?

biceps femoris

12

where can the common tendon of the 2 heads of biceps femoris be felt?

lateral posterior knee

13

what is the innervation of the biceps femoris?

long head: tibial part of sciatic nerve
short head: fibular part of sciatic nerve

14

Clinical relevance: muscle strain
what does the hamstring strain refer to?

excessive stretch or tearing of the muscle fibres

15

when is hamstring strain normally seen?

running or kicking sports

16

What would damage to the muscle fibres of the hamstring likely cause?

rupture of the blood vessels nearby causing haematoma
the haematoma is contained by the overlying facia lata (deep fascia of the thigh - forms outer limit of fascia component)

17

What is the treatment for muscle strain?

RICE
rest, ice, compression, elevation

18

when does an avulsion fracture occur?

when a fragment of the bone breaks away from the main body of the bone

19

what happens in an avulsion fracture of the ischial tuberosity?

the hamstring tendons tear off a piece of the ischial tuberosuty

20

How does an avulsion fracture of the ischial tuberosity occur?

occurs in sports requiring rapid contraction then relaxation - e.g. sprinting, football & hurdling