Knee

Question 1

Rectus femoris

Answer 1

Origin - Anterior iliac spine and acetabulum

Insertion - Base of patella

Nerve supply - Femoral nerve

Extends the knee and flexes the hip

Question 2

Main divisions of the knee joint

Answer 2

Posterior femoral group (3 muscles)

Anterior femoral group (4 muscles

Muscles of medial thigh (sartorius and gracillis)

Muscles of deep posterior leg (popliteus)

Question 3

Vastus lateralis

Answer 3

Origin - upper part of intertrochanteric line and lower border of greater trochanter

Insertion - base and lateral border of patella

Nerve - Femoral Nerve

Extends the knee

Question 4

Vastus medialis

Answer 4

Origin - Lower part intertrochanteric line and upper part medial supercondylar line

Insertion - medial border of patella

Nerve - femoral nerve

extends the knee

Question 5

Vastus intermedius

Answer 5

Origin - Upper 2/3 of anterior and lateral surface of femur

Insertion - Base of patella with rectus femoris

Nerve - femoral nerve

extends the knee

Question 6

Function of the quads

Answer 6

Powerful extensor

Work eccentrically to control flexion

Question 7

Sartorius

Answer 7

Origin - ASIS

Insertion - Upper medial part shaft of tibia

Nerve - femoral nerve

Flexion, lateral rotation and Abduction of the hip
Flexes the knee

Question 8

Hamstrings

Answer 8

Semitendinosus - half tendon

Semimembranosus - half membrane

Bicep femoris - 2 heads

All supplied by sciatic nerve

All produce flexion of knee and hip extension

Question 9

Function of hamstrings

Answer 9

Balancing pelvis on trunk

Returning the upper body to upright from being bent forwards

Deceleration of the tibia in gait

Question 10

Tensor fascia Lata

Answer 10

Origin - ASIS and iliac crest

Insertion - lateral tibial condyle

nerve - Superior gluteal nerve

adducts and medially rotates the hip, assists in knee flexion

Question 11

Popliteus

Answer 11

Origin - outer surface lateral condyle of femur

Insertion - posterior surface of tibia above soleal line

Nerve - Tibial nerve

Flexes the knee and medially rotates the tibia

Unlocks the knee when the foot is fixed enabling it to flex
Popliteus is the key that unlocks the knee

Question 12

Function of the knee

Answer 12

Mobility

Weight bearing

stability

Question 13

articular surfaces

Answer 13

Femur:
Convex femoral condyles

Intercondylar notch continues groove of the patella surface

Tibia:
Flat and separated by intercondylar eminence

eminence lodges into intercondylar notch of femur

Concave

Question 14

Patella

Answer 14

Oval articular surface

Divided into lateral and medial facets

Question 15

Valgus and Varus

Answer 15

Varus - outward angle

Valgus - inward angle
(knock knees)

Question 16

Joint capsule

Answer 16

Knee is surrounded by thick ligamentous sheath composed mainly of muscle tendons

No complete independent fibrous capsule

Question 17

Synovial membrane

Answer 17

Lines the joint capsule

Tibia: towards cruciate ligaments so they are intracapsular but extrasynovial

Patella: membrane extends as the suprapatella bursa which prevents friction between quads and femur

Question 18

Functions of Menisci

Answer 18

Improve Congruence
Weight bearing
Shock absorb
Aid lubrication
Participate in locking mechanism

Question 19

Menisci

Answer 19

in cross section between femoral and tibial condyles

Mede of fibrocartilage and crescent shaped

Medial menisci - broader posteriorly than anteriorly

Lateral - uniform width

In flexion menisci move posteriorly on the tibial condyles so posterior parst project beyond tibial condyles

In extension menisci move anteriorly with anterior parts projecting beyond the anterior tibial condyles

Transverse ligament connects 2 menisci anteriorly

Question 20

Knee extension

Answer 20

As its convex on concave it glides posteriorly and rolls anteriorly

Posterior cruciate ligament prevents it from sliding off backwards (dislocating)

As tibia is fixed the femur medially rotates at the end of extension

This rotation at the end of extension is the locking of the knee

Question 21

Ligamentum patellae

Answer 21

Very strong ligament

Connects apex of patella to the tibial tuberosity

Question 22

Semitendinosus

Answer 22

Origin - lower medial facet on ischial tuberosity

Insertion - Medial surface upper part of tibia

Nerve - sciatic nerve

Question 23

Semimembranosus

Answer 23

Origin - Upper Lateral facet on ischial tuberosity

Insertion - Posteromedial surface of medial tibial condyle

Nerve - Sciatic

Question 24

Bicep Femoris

Answer 24

Origin - lower medial facet on ischial tuberosity

Insertion - Head of fibula

Nerve - Sciatic nerve

Question 25

Knee joint in flexion

Answer 25

Tibia is concave on a convex femur. Same direction

at the joint it glides posteriorly
The limb also moves posteriorly

Rotation at the start of flexion as the unlocking of the knee