knee joint

Question 1

2 parts of knee joint
 function (3)

Answer 1

1. tibiofemoral and patellofemoral
functions 
   1. shortens leg during swing 
   2. lengthens led during stance
   3. transmits weight btwn hip and ankle

Question 2

anatomy of knee joint (2)

Answer 2

1. femoral condyles sit on shallow menisci = exposed shallow joint
2. long exposed bone levers (femur and tibia) = most injured joint in body

Question 3

normal ROM of knee and needed ROM for…
walking
stairs

Answer 3

normal = 0-140 degrees
walking = 65 degrees
stairs = 110

Question 4

tibiofemoral joint - type and movements available

Answer 4

1. modified hinge joint

2. biaxial - flex/ extend and rotation

Question 5

volitional movement of tibiofemoral joint

Answer 5

1. volitional rotation using med and lateral hamstrings

Question 6

mechanical movement of tibiofemoral joint

Answer 6

1. medial condyle is larger than lateral

2. in open chain- going into terminal extension - lat side runs out of room to keep moving => ext rotation of tibia

Question 7

open vs. close kinematic rotation
rotary and translatory movement
rotation of tibia and femur when going into and out of terminal ext

Answer 7

open
1. tibia on femur = concave on convex (rotary same as translatory)
2. terminal ext -> slight flexion = slight tibial int rotation
closed
1. femur on tibia = convex on concave so rotary opposite of translatory
2. slight flex -> terminal ext = femoral int rotation
*see sticky note on computer

Question 8

nemonic for closed chain kinematics

Answer 8

FE - Flex -> ext

MuR = medial rotation

Question 9

patellofemoral joint

type of joint and movements available

Answer 9

1. diarthrodial

2. planar joint

Question 10

patella
action on quads

translatory movements (when you flex and extend your knee)

Answer 10

1. lengthens quads b/c of angle of insertion => increases mechanical advantage

translatory:

2. going into extension- patella glids sup and lateral
3. going into flexion - patella glides inf and medial

Question 11

movements of patella in transverse plane

Answer 11

1. z- axis
2. flexion- med tilting
3. extension- lat tilting
   inferior pole is point of reference

Question 12

tibial tubercles
location
where they are in extension

Answer 12

1. located on top of tibial plateau

2. in extension lodged in intertrochanteric fossa and contribute to locking mechanism

Question 13

menisci
size
shape
function

Answer 13

1. medial is larger than lateral
2. lateral- is circular
3. medial- crescent and bound down stronger
4. function is shock absorption

Question 14

two types of menisci tears

and where it will heal faster

Answer 14

1. transverse/ radial - goes horizontal
2. longitudinal - bucket handle
3. outside is more likely to heal because more blood supply

Question 15

2 cardinal signs of meniscal issue

Answer 15

1. compliant knee locking

2. excessive clicking

Question 16

2 meniscal ligaments

Answer 16

1. meniscal-tibial ligaments (coronary)

2. transverse ligament- binds menisci to each other

Question 17

knee stability

anatomy

Answer 17

1. long levers w/ shallow articulation- contractile and non-contractile tissues give support

Question 18

knee stability- 
 ant support (2)

Answer 18

1. quad tendons

2. infrapatellar tendon

Question 19

knee stability
 posterior support (6)

Answer 19

1. joint capsule - snaps knee back
2. popliteus- in closed chain does ER rotation of femur => unlocking; open chain does IR rotation
3. gastroc heads - cross knee joint
4. arcuate popliteal ligament
5. posterior oblique popliteal ligament
6. hamstring tendons

Question 20

knee stability - cruciate ligaments

where they attach and purpose

Answer 20

give ant and posterior stabilization
PCL
1. posterior on tib -> med femoral condyle.
2. prevents posterior slippage of tib on femor (or visa versa)
ACL
1. ant on tib -> lat femoral condyle
2. prevents anterior slippage of tib on femur

Question 21

drawer sign

Answer 21

1. hooklying position, grab behind gastroc head and try to translate the fib forward. excessive translation = tear or strain in ACL

Question 22

ligament of wristberg

Answer 22

posterior part of lateral meniscus and goes to medial femoral condyle

Question 23

medial/ lateral support of knee
ligaments (4)
unhappy triad of knee injury (what usually causes it)
muscle attachments (2 med)

Answer 23

1. medial and lateral collateral ligaments
2. patellofemoral ligament
3. IT band
4. unhappy triad = Med collateral, ACL, and medial meniscus
   from lateral side impact
   muscles:
   pes anserine- gives medial stabilization
   medial hamstrings

Question 24

joint slide (2)

Answer 24

1. more knee flexion- femoral condyles slide anterior

2. flex -> extend - joint surfaces slide posterior

Question 25

instantaneous axis of rotation

Answer 25

1. axis is constantly changing because of sliding movements around joint, usually around femoral condyle

Question 26

knee bursae (5)

Answer 26

1. pre-patella bursa- btwn skin and patella 2. infrapatella bursa- 2- superficial- btwn skin and tendon deep - underneath infrapatellar tendon 3. suprapatella bursa- btwn quadriceps tendon and bone 4. gastroc bursa- gastroc head and medial femoral condyle 5. pes anserine bursa

Question 27

muscles that do knee extension 5 quads articularis genu

Answer 27

``` quads: 1. vastus lateralis- strongest 2. vastus intermedius 3. vastus medialis longus 4. vastus medialis oblique 5. rec fem articularis genu inserts into joint capsule -> suprapatellar bursa does the last 15 degrees of extension, helps terminal extension, pulls joint capsule up and out of the way ```

Question 28

quad hamstring ratio

Answer 28

1. hamstrings have 50-60% strenghth of quads

Question 29

when can quads generate most amount of torque

Answer 29

1. sitting position 30-60 degrees (45) | 2. in this range pt can generate most force and lift more weight

Question 30

Q- angle (quadricep angle)- how you measure normal angles what happens in genu valgum and genu varum

Answer 30

2 lines 1. ASIS drop down to midpoint of patella 2. line thru tibial crest, tibial tuberosity -> thru patella , straight up angle is above knee cap 3. regular is 10-15 degrees (women are closer to 15) 4. genu valgum- q-angle is larger b/c excessive lateral tracking of patella 5. genu varum- q-angle is smaller because b/c excessive medial tracking of patella

Question 31

posterior knee muscles (flexors) | 4 muscles

Answer 31

3 muscles: 1. hamstrings - do knee flexion w/ rotation of tibia (medial do IR) 2. plantaris (lat fem condyle -> achilles tendon) 3. gastroc 4. popliteus - oblique med- > lat, does unlocking (ER femur, IR tibia)

Question 32

gastroc when can they generate most torque? shunt vs. spurt

Answer 32

1. can generate most amt of torque when knee is flexed at 90 2. shunt at knee (stability) -close to origin 3. spurt at ankle (movement)- far from origin

Question 33

movement of patella in frontal plane which axis what happens in flexion and extension

Answer 33

1. y axis 2. flexion = lateral rotation (spin) 3. extension =med rotation 3. inferior pole is point of reference

Question 34

movement of patella in saggital plane which axis what happens in flexion

Answer 34

1. x- axis 2. in flexion - sup pole => forward, inf pole -> back 3. inferior pole is point of reference