MSK Muscles of the thigh

Question 1

Name the muscles in the anterior compartment of the thigh

Answer 1

Pectineus
Sartorius
Quadriceps femoris
End of the iliopsoas passes into the anterior compartment

Question 2

What 2 muscles make up the iliopsoas?

What are their attachments and actions?

Answer 2

Iliacus and Psoas major (come together to form a common tendon)

Psoas major originates from lumbar vertebrae and iliac from the iliac fossa
They insert onto the lesser trochanter

Actions:
Flexion and assists lateral rotation

Question 3

What are the attachments and actions of the quadriceps femoris?

Answer 3

Rectus femoris originates from ilium
Vastus lateralis originated from greater trochanter and linea aspera
Vastus intermedius originates from anterior shaft
Vastus medialis originates from intertrochanteric line and linea aspera
ALL attaches to patella by quadriceps femoris tendon

Actions:
Flexes hip, extends knee

Question 4

What are the attachments and actions of the sartorius?

Answer 4

Longest muscle in body
Originates from ASIS and attaches to superior medial surface of TIBIA

Actions:
Flexor, abductor and lateral rotator

Question 5

What are the attachments and actions of the pectineus?

Answer 5

Flat muscle - base of femoral triangle

Originates from pectineal line on anterior pelvis and attaches to pectineal line on posterior femur just inferior to lesser trochanter

Actions:
Adduction and flexion

Question 6

What is the innervation of the anterior thigh muscles?

Answer 6

All femoral nerve (L2-4)

Question 7

How do you test for femoral nerve damage?

Answer 7

Test quadriceps femoris function

Supine position with slightly flexed knee, ask patient to extend leg against resistance - quads should be visible

Question 8

Name the muscles in the medial compartment of the thigh

Answer 8

Adductor longus brevis magnus, obturator externus, gracilis

Question 9

What are the attachments and actions of the adductor magnus?

Answer 9

Largest muscle of medial compartment and most posterior, split into the adductor and hamstring part

Adductor part originates from inferior rami of pubic and rami of ischium and attaches to linea aspera
Hamstring part originates from ischial tuberosity and attaches to adductor tubercle on distal and medial femur.

Actions:
Both parts adduct
Adductor flexes thigh and hamstring extends thigh

Question 10

What are the attachments and actions of the adductor longus?

Answer 10

Forms medial border of femoral triangle

Originates from pubis and attaches broadly to linea aspera

Actions:
Adduction and medial rotation

Question 11

What are the attachments and actions of the adductor brevis?

Answer 11

Originates from pubis and inferior pubic rami and attaches to linea aspera on posterior femur

Actions:
Adduction

Question 12

What are the attachments and actions of the obturator externus?

Answer 12

Most superior medial thigh muscle

Originates from membrane of obturator foramen and adjacent bone, passes under the neck of femur and attaches to posterior greater trochanter

Actions:
Lateral rotation

Question 13

What are the attachments and actions of the gracilis?

Answer 13

Most superficial and medial, crosses hip and knee

Originates from inferior rami of pubis and body of pubis and attaches to medial surface of tibia

Actions:
Adduction of thigh, flexion of knee

Question 14

What is the innervation and blood supply to the medial thigh muscles?

Answer 14

All obturator nerve (L2-4) except hamstring part of adductor magnus which is tibial nerve (L4-S3)

Obturator artery

Question 15

What is groin strain?

Answer 15

Strain of the adductor muscles of the thigh
Proximal parts of the muscles are most usually affected, tearing near their bony attachments to the pelvis

Usually caused by sports that require extreme stretching.
Treatment is RICE

Question 16

Name the muscles in the posterior compartment of the thigh

Answer 16

Biceps femoris
Semitendinosus
Semimembranosus

Question 17

What are the attachments and actions of the biceps femoris?

Answer 17

Most lateral muscle of posterior thigh, the tendon can be felt posterior knee

Long head originates from ischial tuberosity and short head originates from linea aspera, they inserts into the head of fibula

Actions:
Extends hip, flexes knee
Lateral rotation

Question 18

What are the attachments and actions of the semitendinosus?

Answer 18

Covers most of semimembranosus

Originates from ischial tuberosity and attaches to medial tibia

Actions:
Extends hip, flexes knee
Medial rotation

Question 19

What are the attachments and actions of the semimembranosus?

Answer 19

Covered by semitendinosus

Originates from ischial tuberosity and attaches to medial condyle of tibia

Actions:
Extends hip, flexes knee
Medial rotation

Question 20

What is the innervation of the posterior thigh muscles?

biceps femoris, semi m and ten

Answer 20

Semiten and semimen = tibial part of sciatic nerve
Biceps femoris = common fibular part of sciatic nerve

Sciatic nerve is L4-S3

Question 21

What is the cause and treatment of a hamstring strain?

Answer 21

Excessive stretching or tearing of muscle fibres
Damage to fibres likely to damage surrounding vessels producing a haematoma
Treatment is RICE

Question 22

How does an avulsion fracture to the ischial tuberosity occur?

Answer 22

The hamstrings tendons pull of a piece of the ischial tuberosity