Movements of the Knee Joint - The Muscles

Question 1

Which movements are permitted by the knee joint?

Answer 1

Flexion, Extension, Medial rotation and Lateral rotation

Question 2

Which muscles enable flexion of the knee?

Answer 2

The hamstrings: gluteus maximus, biceps femoris, semimembranosus, semitendinosus
Gracilis
Sartorius
Popliteus

Question 3

Which nerves innervate the flexors of the knee?

Answer 3

Gluteus maximus - inferior gluteal nerve
Biceps femoris - long head - tibial nerve, short head - common fibular nerve
Semimembranosus - tibial nerve
Semitendonosus - tibial nerve
Gracilis - obturator nerve
Sartorius - femoral nerve
Popliteus - tibial nerve

Question 4

Which muscles enable extension of the knee?

Answer 4

Quadriceps femoris (rectus femoris, vastus medialis, lateralis, and intermedius)

Question 5

Which nerves innervate the extensors of the knee?

Answer 5

Rectus femoris - femoral nerve
Vastus medialis - femoral nerve
Vastus intermedius - femoral nerve
Vastus lateralis - femoral nerve

Question 6

What is special about Vastus Medialis?

Answer 6

As well as extending the knee, it is especially good at stabilising the patella due to the horizontal fibres at the distal end.

Question 7

Which muscle enables lateral rotation of the knee?

Answer 7

Biceps femoris

Question 8

Which nerve innervates the lateral rotator of the knee?

Answer 8

Short head - common fibular nerve

Long head - tibial nerve

Question 9

Which muscles enable medial rotation of the knee?

Answer 9

Semimembranosus 
Semitendinosus 
Gracilis 
Sartorius 
Popliteus

Question 10

Which nerves innervate the medial rotators of the knee?

Answer 10

Semimembranosus - tibial nerve 
Semitendinosus - tibial nerve 
Gracilis - obturator nerve 
Sartorius - femoral nerve 
Popliteus - tibial nerve

Question 11

When can medial and lateral rotation only occur?

Answer 11

Lateral and medial rotation can only occur when the knee is flexed. If the knee is not flexed, medial and lateral rotation occurs at the hip

Question 12

Name the origin and insertion of Gluteus maximus

Answer 12

Origin - external surface of the ilium behind the posterior gluteal line, the dorsal surface of the sacrum and the lateral margin of the coccyx
Insertion - upper fibres - posterior part of the iliotibial tract - lower fibres - gluteal tuberosity of the proximal femur

Question 13

Name the origin and insertion of Biceps Femoris

Answer 13

LONG HEAD
Origin - Ischial tuberosity
Insertion - Head of fibula and lateral condyle of the tibia
SHORT HEAD
Origin - Lateral lip of the linea aspera of the femur
Insertion - Head of the fibula and lateral condyle of the tibia

Question 14

Name the origin and insertion of Semimembranosus

Answer 14

Origin - Outer surface of the ischial tuberosity

Insertion - Medial tibial condyle

Question 15

Name the origin and insertion of Semitendinosus

Answer 15

Origin - Ischial tuberosity

Insertion - Medial surface of the tibial tuberosity

Question 16

Name the origin and insertion of Gracilis

Answer 16

Origin - Pubic symphysis and the inferior pubic ramus

Insertion - Medial surface of the tibia

Question 17

Name the origin and insertion of Sartorius

Answer 17

Origin - Anterior superior iliac spine (ASIS)

Insertion - Medial part of the tibia near the tibial tuberosity

Question 18

Name the origin and insertion of Popliteus

Answer 18

Origin - Lateral condyle of the femur

Insertion - Posterior surface of the tibia above the soleus

Question 19

Name the origin and insertion of Rectus Femoris

Answer 19

Origin - Anterior inferior iliac spine and the superior part of the acetabulum
Insertion - Tibial tuberosity and the patella via the quadriceps tendon

Question 20

Name the origin and insertion of Vastus Medialis

Answer 20

Origin - medial lip of the lines aspera of the femur and the intertrochanteric line
Insertion - the patella via the patella tendon and tibial tuberosity via the patellar ligament

Question 21

Name the origin and insertion of Vastus Intermedius

Answer 21

Origin - anterior and lateral surface of the femur

Insertion - tibial tuberosity via the patellar ligament

Question 22

Name the origin and insertion of Vastus Lateralis

Answer 22

Origin - greater trochanter of the femur

Insertion - tibial tuberosity via the patellar ligament