Knee FINAL

Question 1

2 articulations of the knee

Answer 1

tibiofemoral

patellofemoral

Question 2

the medial & lateral condyles of the femur articulate with the ________, which are attached to the superior articular surface of the ______

Answer 2

• menisci

- tibia

Question 3

the tibiofemoral joint is considered a ________ joint due to its restricting _______ & the occurrence of ________ motions

Answer 3

• modified
• ligaments
• rotation

Question 4

what is the screw home mechanism

Answer 4

during the last few degrees of the knee extension, the anatomy of the knee requires the tibia to slightly externally rotate

Question 5

explain the screw home mechanism

Answer 5

during the last few degrees of the knee extension, the anatomy of the knee requires the tibia to slightly externally rotate

Question 6

when flexing the knee from a fully extended position, slight ____ of the _____ occurs

Answer 6

IR [internal rotation], tibia

Question 7

what are menisci? what shape are they?

Answer 7

fibrocartilaginous discs located between the tibia and femur; semilunar shape

Question 8

what do the menisci do?

Answer 8

distribute load at the knee to absorb shock

Question 9

outer ___-___ % menisci receive blood supply

Answer 9

10-30%

Question 10

what is the largest sesamoid bone

Answer 10

patella

Question 11

the patella is formed within a _____

Answer 11

tendon

Question 12

the patella rides in the ____ ______ of the femur, encased in the _______ tendon

Answer 12

• trochlear groove

- patellar

Question 13

what is the posterior surface of the patella covered with? What does this do?

Answer 13

articular cartilage; reduces friction between patella and femur

Question 14

the _______ surface of the patella contains ___ facets

Answer 14

posterior; 7

Question 15

the patellofemoral joint has a ______ facet and a ______ facet

Answer 15

lateral; medial

Question 16

what are the portions of the lateral and medial facets

Answer 16

1. superior
2. middle
3. inferior

Question 17

what is the odd facet of the patellofemoral joint

Answer 17

located on the far medial aspect; only comes into contact with the femur in full knee flexion

Question 18

what does the patella do?

Answer 18

increases angle of pull of the quads on the tibia

Question 19

the patella improves the mechanical advantage of the quadriceps as much as ___%

Answer 19

50%

Question 20

what are the quadriceps muscles

Answer 20

1. vastus medialis
2. vastus lateralis
3. vastus intermedius
4. rectus femoris

Question 21

what is the articulates genu

Answer 21

elevates the articular capsule of the knee joint

Question 22

hamstring muscles

Answer 22

1. biceps femoris short head
2. biceps femoris long head
3. semimembranosus
4. semitendinosus

Question 23

where is the popliteus located

Answer 23

deep in the popliteus fossa [posterior knee]

Question 24

what muscle is known as the “key to the knee” muscle? why?

Answer 24

1. Popliteus muscle

2. laterally rotates the tibia & unlocks the knee to begin knee flexion

Question 25

the tibia can rotate when the knee is _______

Answer 25

flexed

Question 26

what muscles contribute to tibial internal rotation

Answer 26

1. semimembranosus

2. semitendinosus

Question 27

muscle responsible for tibia external rotation

Answer 27

biceps femoris

Question 28

ligaments of the knee are split into what two groups

Answer 28

cruciate ligaments and colateral ligaments

Question 29

2 cruciate ligaments

Answer 29

1. anterior cruciate ligament (ACL)

2. posterior cruciate ligament (PCL)

Question 30

2 colateral ligaments

Answer 30

1. medial colateral ligament [MCL]

2. lateral colateral ligament [LCL]

Question 31

what is normal knee range of motion from flexion to extension? Up to ____ degrees of hyperextension is common

Answer 31

0-140 degrees; 15 degrees

Question 32

normal level ground walking requires ___ to ____ degrees of knee flexion

Answer 32

60-120

Question 33

normal level ground walking requires ___ to ____ degrees of knee flexion

Answer 33

60-120

Question 34

after surgery it is very important to achieve full ROM, especially _____ in order to walk with a normal gait again

Answer 34

extension

Question 35

running requires _____ to ____ degrees of knee flexion

Answer 35

120-140

Question 36

to rise from a seated position at least ____ degrees of knee _____ is needed for most chairs; lower chairs may require _____ degrees

Answer 36

90; flexion; 115

Question 37

what occurs in your knees biomechanically during a squat

Answer 37

surface motions between the tibia and femur: roll, slide & spin

Question 38

what happens in your knees biomechanically during the first 10 degrees of a squat

Answer 38

spin occurs from the unblocking mechanism; slight posterior roll of femur on the tibia

Question 39

What 3 things happen as you descend deeper in the squat

Answer 39

1. condyles roll posteriorly on to the posterior aspect of the menisci
2. the femur slides anterior proportionally with the deepness of the squat
3. femoral translation is regulated by the ACL & PCL

Question 40

the lowest compressive forces are at ____ degrees of knee flexion and at ___ degrees of knee flexion [in open chain]

Answer 40

90 degrees; 0 degrees

Question 41

the highest compressive forces are at ___ degrees of knee flexion. What is significant about this angle?

Answer 41

25

• where pain is felt usually
• highest compressive forces

Question 42

what two things are recommended for someone with patellofemoral pain

Answer 42

1. perform leg extension ONLY from 90 deg. to 60 deg. of knee flexion
2. perform “terminal knee extensions” [extend leg from 10-15 deg. flexion]