Knee

Question 1

Knee joint

Answer 1

Links 2 largest bones in the body

largest and one of most complex joints

Question 2

joint

Answer 2

femur

patella (kneecap)

tibia

fibula

Question 3

functions

Answer 3

support body weight

transmit forces between femur and tibia

provide movement for movement and activity

Question 4

stability

Answer 4

has to absorb the body weight and take impacts

Question 5

mobility

Answer 5

allows freely moving actions flexion and extension

Question 7

tibiofemoral joint

Answer 7

synovial joint

between femoral condyles and tibial articular surfaces

Question 8

femoral concyles

Answer 8

at the distal end of femur

Question 9

tibia condyles

Answer 9

at proximal end of tibia

Question 10

medial articular surface

Answer 10

larger and more oval

Question 11

lateral articular surface

Answer 11

smaller and circular

Question 12

function of menisci located at joints

Answer 12

increase congruence between articular surfaces

assist weight bearing across joint

shock absorbers

facilitate accessory movements

Question 13

4 major ligaments of the knee

Answer 13

medial collateral ligament

lateral collateral ligament

anterior cruciate ligament

posterior cruciate ligament

Question 14

Medial collateral ligament (MCL)

Answer 14

broad flat band, 10cm long

extra-capsular

prevent valgus displacement- prevent adduction of a joint

Question 15

lateral collateral ligament (LCL)

Answer 15

extra-capsular

a strong cord

prevents varus displacement- prevent abduction of a joint

Question 16

anterior cruciate ligament (ACL)

Answer 16

intra-capsular

from anterior intercondylar area of tibia to lateral femoral condyle

prevents anterior tibial displacement- knee moving forwards away from joint

Question 17

Posterior Cruciate ligament (PCL)

Answer 17

intra-capsular

posterior intercondyar area of tibia to medial femoral condyle

prevents posterior tibial displacement- knee moving backwards from joint

Question 18

patellofemoral joint

Answer 18

synovial saddle joint

between
articular surface of patella
and
patellar surface of femur

Question 19

patella

Answer 19

largest sesamoid bone in body

embedded in tendon of quadriceps

Question 20

patella function

Answer 20

an anatomic pulley

reduces friction between quadriceps tendon and femoral condyles

Question 21

patella (articular surface)

Answer 21

oval shaped, cartilage covered

vertical ridge separates medial and lateral areas

lateral area larger

medial area samller

Question 22

femoral condyles- patellar surface of femur

Answer 22

cartilage-covered surface which articulates with patella

Question 23

PFJ (inferior view)

Answer 23

patella ridge articulates with groove of patellar surface

Question 24

patella movements

Answer 24

moves distally in flexion

moves proximally in extension

Question 25

shared features between the joints

Question 26

joint capsule

Answer 26

reinforced by ligaments and tendons when complete

Question 27

bursae

Answer 27

fluid- filled sacs reduce friction 13-15 in knee area

Question 28

a bi-axial joint

Answer 28

tibiofemoral joint is bi-axial movements occur in 2 planes/ around 2 axis

Question 29

movements

Answer 29

1. flexion and extension around horizontal axis in sagittal plane 2. medial and lateral rotation around vertical axis in transverse plane

Question 30

flexion and extension ROM

Answer 30

140 degrees flexion 0 degrees extension

Question 31

medial and lateral tibial rotation

Answer 31

at 90 degrees flexion 25 degrees medial rotation 40 degrees lateral rotation

Question 32

close packed position- knee locking mechanism

Answer 32

close-packed position of knee is full extension no rotation possible in this position

Question 33

knee locking mechanism

Answer 33

There is the observable rotation of a knee during flexion as well as extension. The rotation is important for the healthy motion of a knee. During the last 30 degrees of the knee extension, a tibia (open chain) or even femur (closed chain) must externally or internally rotate, respectively, about 10 degrees. This slight rotation is owing to the inequality of an articular surface of the femur condyles. Rotation must happen to achieve full extension & then flexion from full extension.

Question 34

knee flexors

Answer 34

Biceps femoris, semimembanosus, semitendinosus, sartorius, gracilis

Question 35

bicep femoris (flexor)

Answer 35

Origin: Ischial tuberosity, linea aspera, and lateral supracondylar line. Insertion: Head of fibula. Action: Flexes and laterally rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial (L5-S2) and common fibular (L5-S2) divisions of sciatic nerve.

Question 36

semimembranosus (flexors)

Answer 36

Origin: Ischial tuberosity. Insertion: Medial condyle of tibia. Action: Flexes and medially rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial division of sciatic nerve

Question 37

semitendinosus

Answer 37

Origin: Ischial tuberosity. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial division of sciatic nerve

Question 38

sartorius

Answer 38

Origin: Anterior superior iliac spine. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; assists in flexion, abduction and lateral rotation of thigh at hip joint. Innervation: Femoral nerve

Question 39

gracilis

Answer 39

Origin: Body of pubis and inferior pubic ramus. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; assists in adduction of thigh at hip joint. Innervation: Obturator nerve

Question 40

knee extensors

Answer 40

Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, tensor fascia latae

Question 41

Rectus femoris

Answer 41

Origin: Anterior inferior iliac spine and supraacetabular groove of ilium. Insertion: Tibial tuberosity, via tendon of quadriceps femoris muscle and patellar ligament. Action: Extends leg at knee joint; flexes thigh at hip joint. Innervation: Femoral nerve

Question 42

vastus lateralis

Answer 42

Origin: Intertrochanteric line, greater trochanter, gluteal tuberosity, and lateral lip of linea aspera of femur. Insertion: Tibial tuberosity, via tendon of quadriceps femoris muscle and patellar ligament; lateral border of patella. Action: Extends leg at knee joint. Innervation: Femoral nerve

Question 43

vastus medialis

Answer 43

Origin: Medial part of the intertrochanteric line and medial to the spiral line and linea aspera of the femur, extending inferiorly to the medial supracondylar line. Insertion: Tibial tuberosity, via tendon of quadriceps femoris muscle and patellar ligament, and medial border of patella. Action: Extends leg at knee joint. Innervation: Femoral nerve

Question 44

vastus intermedius

Answer 44

Origin: Anterior and lateral surfaces of body of femur. Insertion: Tibial tuberosity, via tendon of quadriceps femoris muscle and patellar ligament. Action: Extends leg at knee joint. Innervation: Femoral nerve

Question 45

tensor fascia latae

Answer 45

Origin: Anterior superior iliac spine and anterior one third of outer lip of iliac crest. Insertion: Tubercle of iliotibial tract on the tibia, via iliotibial tract. Action: Assists in medial rotation, abduction, and flexion of thigh at hip joint. Innervation: Superior gluteal nerve

Question 46

Popliteus- rotates the femur on a fixed tibia unlocking the knee in extention

Answer 46

Popliteus- Origin: Groove for popliteus muscle. Insertion: Posterior surface of tibia, superior to soleal line. Action: Medially rotates leg at knee joint; “unlocks” knee joint at beginning of knee flexion. Innervation: Tibial nerve

Question 47

medial rotators

Answer 47

Semimembranosus, semitendinosus, sartorius, gracilis

Question 48

Semimembranosus

Answer 48

Origin: Ischial tuberosity. Insertion: Medial condyle of tibia. Action: Flexes and medially rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial division of sciatic nerve

Question 49

semitendinosus

Answer 49

Origin: Ischial tuberosity. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial division of sciatic nerve

Question 50

sartorius

Answer 50

Origin: Anterior superior iliac spine. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; assists in flexion, abduction and lateral rotation of thigh at hip joint. Innervation: Femoral nerve

Question 51

Gracilis

Answer 51

Origin: Body of pubis and inferior pubic ramus. Insertion: Medial aspect of proximal part of tibia. Action: Flexes and medially rotates leg at knee joint; assists in adduction of thigh at hip joint. Innervation: Obturator nerve

Question 52

lateral rotators

Answer 52

bicep femoris- When the knee is semiflexed, the biceps femoris acts to produce external rotation of the leg at the knee12. The long head of the biceps femoris is a weaker knee flexor when the hip is extended and a weaker hip extender when the knee is flexed2. In consequence of its oblique direction, the biceps femoris rotates the leg slightly outward when the knee is semi-flexed

Question 53

bicep femoris

Answer 53

Origin: Ischial tuberosity, linea aspera, and lateral supracondylar line. Insertion: Head of fibula. Action: Flexes and laterally rotates leg at knee joint; extends thigh at hip joint. Innervation: Tibial (L5-S2) and common fibular (L5-S2) divisions of sciatic nerve.