Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biomechanics Final > Knee > Flashcards

Knee Flashcards

1
Q

Extensor lag:

Functional role of _____

A “______” between femur and quads

Increases the ______ moment arm of the _______ mechanism

> est between ___-____ deg

A

patella

spacer

internal

extensor

20; 60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Reasons for PF alignment

  1. ______
  2. Local factors: act _____ on the PF joint
  3. Global factors: related to ________ of the bones/ joints of LE
A

Quadriceps
directly
alignment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can this happen? Slide with valgus unilateral stance

Laxity/injury to ______

Dynamic posture of ______ of femur (weak hip _______/tightness of add; ________ Trendelenburg and GRF shift to ______ knee creating a ______ torque; excessive ______ of ST joint (____ of tibia) reduced strength/neuromuscular control of ______ of hip (thus _____ of femur)

A

MCL

ADD

ABD

compensated

lateral

valgus

pronation

IR
ER
IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Capsule and Reinforcing
Ligaments

Connective tissue reinforcement:
_______ popliteal lig, _______ popliteal lig

Muscular reinforcement: _______, ________, _______ (esp ___)

A

oblique
arcuate

popliteus, gastrocs, popliteus, hamstrings, SM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Connective tissue reinforcement:

Medial: from ____ tendon to ______ capsule medial slide

Muscular- _______ /_______/_______ ______

A

patellar

posterior

SM
SGT
pes anserine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

TF joint: Meniscisi

large _____ femoral condyles and flat, smaller ______plateaus

Excessive motion but soft tissue provides ______ – thus injury can involve many structures

act as _______ to form seats for the femoral condyles

A

convex
stability
gaskets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Menisci are anchored to ________ region of tibia @ ______/______ horns

A

intercondylar
anterior/posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

External edge of each meniscus is attached to tibia and the capsule by _______ ligaments (meniscotibial) – these are loose allowing pivoting

A

coronary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The 2 menisci are connected anteriorly by ________ ligament

A

transverse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Secondary attachments of muscle to menisci

_____
_____
______ to lateral

A

SM
Quads
popliteus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Meniscus

Medial oval shape attaches to ______ and ______ capsule

Lateral more circular, only attaches to _______ capsule, popliteus passes between LCL and LM

A

MCL; ajacent

lateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Blood supply; peripheral 1/3 is called the “_____ zone”

inner 2/3 avascular and called the “_____ zone”

A

red

white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

TF joint:
decreases ______ forces (triples joint contact area and decreases pressure on ______ cartilage)

A

compressive
articular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

TF joint:

WB is ______- meniscus deform peripherally (_____ _____-) becomes ________ stress

Compressive force at knee walk ____-_____x BW and > ____X with stairs

A

axial
hoop stress
tensile

2.5-3
4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

TF joint:

complete lateral ______ increases peak contact pressure 230%

A

meniscectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

TF secondary functions:

_______ joint during motion

_______ articular cartilage

providing _______

A

stabilizing
lubricating
propiception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

________ have been identified in the anterior and posterior horns of menisci

A

mechanoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Meniscal tears (common)

Often associated with _____, _____ rotation of femoral condyles over a fixed ____ knee (can pinch and dislodge _____)

A dislodged or ____ _____ (bucket handle) can mechanically _____ knee motion

Medial injured _____ as frequently- _____ force (large stress on ____/post/med capsule)

Risk increases with ligamentous _____ (esp ACL) and malalignment

A

forceful
axial

WB
meniscus

folded flap
block

2x
valgus
MCL

laxity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

TF joint: Osteokinematics

FLX/EXT

_____ degrees of freedom (F/E and ROT)

Knee must be slightly _____ to have rotation occur

Frontal plane is passively only ___-____ deg

___/___ axis (sagittal plane)

____-_____deg FLX
____-_____ deg hyperext

A

2
flexed
6; 7
ML
130; 150
10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

TF: Osteokinematics

IR and ER

Axial rotation: ________ axis through tibia
(influenced by _____ plane motion) little in EXT

At 90 deg: ____-____ deg of axial rotation; ER __:__ exceeds IR

Rotation named by position of ______ ______ relative to anterior ______ femur

A

longitudinal
sagittal
40; 45
2; 1
tibial tuberosity
distal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

TF joint: FLX/EXT

Tibial on femoral: EXT- tibia rolls and slides ______ on femur; meniscus pulled anteriorly by ______

A

anterior
quads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

TF joint: FLX/EXT

Femoral on tibial EXT- femoral condyles roll _____ and slide _____ on tibia; quads direct the _____ and stabilizes the ______ vs _______ shear of femur

A

anteriorly
posteriorly

quads
meniscus
posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

“Screw home” mechanism:
Full EXT requires ____ deg of ______ during the last _____ deg of ______ (linked and not independent motion); increases joint ______/________

OC tibia _____; CC femur ____

A

10
ER
30
EXT
congruency; stability
ER
IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

“Screw home” driven by:
1. shape of _______ ________ (tibial follows medial condyle and creates _____)

  1. Passive tension of ____
  2. Slight pull of _____
A

femoral condyle

ER

ACL

quads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Relating to “screw home”

Flexion is opposite: the unlocking _____ happens 1st and driven by the _______ (can rotate the femur or tibia)

A

IR
popliteus

29
Q

TF Joint: Arthokinematics

IR/ER

Knee must be _____

Spin between the _____ and _____ surfaces of tibia and femur

Axial rotation of _____ over ______ causes menisci to deform/compress

( ______ and ______ help stabilize)

A

flexed

menisci; articular

femur; tibia

popliteus; SM

30
Q

______ flat and broad

has a superficial and deep part

Superficial: well-defined parallel fibers @ 10 cm med epicondyle to med pat retinaculum fibers to med proximal tibia

Deep: slightly posterior and distal: shorter and oblique attaches to capsule/medial meniscus/SM tendon

A

MCL

31
Q

_____ ligament

Short cord-like

Runs vertical lateral
epicondyle femur to head of fibula

Does not attach to the adjacent meniscus (tendon of popliteus runs between them)

Distally it blends with tendon of biceps femoris

A

LCL

32
Q

Functional considerations for MCL and LCL

Primary: limit motion in _____ plane

Knee extended: _____ vs valgus. force, LCL vs _____ force

A

frontal

MCL
Varus

33
Q

Functional considerations for MCL and LCL

Secondary: provide general ______ tension especially walking near EXT and _______

Protect against ROT extremes (_____ at extreme ER)

A

stability
loading
MCL

34
Q

Most common mechanism of injury for _____ ligament

  1. valgus producing force with foot planted “clip”
  2. severe hyperextension
A

MCL

35
Q

Most common mechanism of injury for _____ ligament

  1. varus producing force with foot planted
  2. severe hyperextension of knee
A

LCL

36
Q

Most common mechanism of injury for _____ ligament

  1. hyperextension of combined hyperextension with ER of knee
A

PCL

37
Q

Most common mechanism of injury for _____ ligament

  1. Large valgus- producing force with foot firmly planted
  2. Large axial rotation torque applied to knee (either rotation)
  3. Any combination above, especially involving strong quad contraction with knee in near EXT or full EXT
  4. Severe hyperextension
A

ACL

38
Q

Most common mechanism of injury for _____ ligament

  1. Falling on a fully flexed knee (ankle PF)
  2. Any event that causes a forceful posterior translation of tibia or ant translation of femur, esp with knee flexed
  3. large axial rotation, valgus-varus torque with foot planted, especially with knee flexed
  4. Severe hyperextension
A

PCL

39
Q

ACL and PCL

_____ within the intercondylar notch intracapsular, _____ by extensive synovial membrane

______ blood supply

Named for attachment on tibia ( ______ and _____)

Together resist extremes of all motions- but primarily ___/____ shear forces between tibia and femur in sagittal plane motions cutting (_____ and ______ planes)

Helps guides arthrokinematics and provides propiceptive feedback (________)

A

cross
covered

poor

thick; strong

AP

frontal; horizontal

mechanoreceptors

40
Q

ACL

_______ tibia

Runs ____/_____/_____ to medial side of lateral condyle

Collagen fibers _____ on each other

Some fibers are taut in ______ but increasingly taut in _____ (esp ___-____ bundle)

A

anterior

sup/post/lat

twist

flexion

ext

posted

41
Q

ACL

Last ____- _____ deg of EXT the force of quads pulls the tibia _____

A

50; 60
anterior

41
Q

Anterior drawer test:

_____ spasm could prevent good test

A

HS

42
Q

Common mechanism of injury ACL

______ spatial orientation and multiple ____ bundles… may directions to resist

Is highly vulnerable if _____ in extremes of motion (high velocity)

Factors: speed and direction GRF, amount of direction of compressive and _____ forces; control and ____ of muscular forces; _____ and strength issues; ______ of trunk and lower limb

Most requently _____ lig in knee

A

Oblique

multiple

tensioned

shear

timing

integrity

alignment

ruptured

43
Q

70% of sports injuries are related to ___-____ ACL

A

non-contact

44
Q

Strong quad activation: can cause “____” collapse and excessive _____ (femur IR)

A

valgus
ER

45
Q

PCL

Majority becomes increasingly taut with greater _______ (___-____ deg >est)

Slack in ___/____ deg into EXT

Limits _____ glide

A

flexion; 90; 120
30; 40
posterior

46
Q

Knee extension: quadriceps innervated by _____ nerve

A

femoral

47
Q

Knee Rotation:
Internal:
- Sartorius ( )
- Gracilis ( )
- SM ( )
- ST ( )
- Popliteus ( )

External
Biceps femoris ( )

A

femoral
obturator
sciatic
sciatic
tibial
sciatic

48
Q

Knee Flexion:
SM ( )
ST ( )
Bicep femoris ( )
Sartorius/Gracilis ( / )

Gastrocnemius/Plantaris ( )
Popliteus ( )

A

sciatic x3

femoral; obturator

tibial
tibial

49
Q

Largest afferent to knee _____ _____ nerve

A

posterior tibial

50
Q

afferent fibers in _______ nerve
Carries sensation from skin over medial knee and post/post-medial capsule

afferent fibers in ________ nerve
Carries sensation from ant-medial and ant-lateral capsule

A

obturator

femoral

51
Q

_______ _______ - AIIS & immediately superior to acetabulum

Vastus _______ - est cross sectional area

Vastus _______- extends farther toward the knee, 2 sections

Vastus _______ - deep to RF and VL

________ _______ - deep to VI, poorly defined, runs distally into the capsule/synovial membrane (pulls them prox during ext)

A

Rf
Lat
Med
Intermed
Articularis genu

52
Q

RF
VL
VM
VIM forms strong ______ tendon

_______ tendon connects apex to tibial tuberosity

A

quadriceps

patellar

53
Q

Functional considerations

_________ functions: stabilizes to protect the knee

________ functions: controls the rate of descent of the body’s COM (sitting, squatting landing from a jump)

controls the rate of descent of the body’s COM (sitting, squatting landing from a jump)

Step down

________ functions: Accelerates tibia/femur toward extension…raises COG: jump, step up, stand up, running uphill.

A

isometric
eccentric
concentric

54
Q

______ torque

External load (item being held)
*blue

_______ torque
Muscle force X its internal moment arm (red)

The ET must be met or exceed by an opposite _____

A

external

internal
IT

55
Q

The ______ muscle unlocks the knee when walking, by ______ ROT the femur on tibia during _____ chain

OC: it _____ rotates the tibia on femur

A

popliteus

laterally

CC

medially

55
Q

Knee Flexors- Rotators

_______, ______, ______, _______ all flex and rotate (gastroc only non rotator)

Roatation- IR (___/____) ER (____)

A

HS
sartorius
popliteus
gracilis

SM/ST/ BF

56
Q

Knee flexors- Rotators

Sartorius/Gracilis -_____ _____- posterior to knee axis- so IR; medial knee (resists knee ____ and _____ loads_

A

pes anserine

ER
Valgus

57
Q

Popliteus screw home

unlocks the knee by either ________ rotating the femur or _______ rotating the ______

A

externally; Internally tibia

58
Q

EROT @ knee

short head of ____ _____ contracts to accelerate the femur ______

Active force from the pes anserinus muscles in conjunction with a passive force from the stretched medial collateral ligament(MCL)and oblique popliteal ligament (not shown) helps to ______

A

biceps femoris

internally

decelerate

59
Q

Genu recurvatum is > ___ deg of hperextension

LOG is _____ to knee

Poor _____ control, _______ disease- spasticity of quad/weakness of flexors; ______/laxity

A

10
anterior
postural
neuromuscular
overuse

60
Q

ACL and rehab
Avoid exercises where _____/_______ quad contractions create _____ translations of the tibia early on rehab to damage tissue

Muscle line of force changes with _____ angle

Risk is when force in _______ to ACL action and muscular force magnitude increases

A

repetitive/ strong

flexion

opposition

61
Q

Gastroc and Plantaris

Action:
Nerve:

A

Knee FLX

61
Q

Biceps femoris (short head)
Action:
Nerve:

A
62
Q

Biceps femoris (long head)
Action:
Nerve:

A
63
Q

Semimembranosus and tendinosus

Action:
Nerve:

A

Knee FLX and IR
Sciatic

64
Q

Popliteus
Action:
Nerve:

A

Knee FLX and IR
tibial

65
Q

Quad femoris
Action:
Nerve:

A

Knee EXT and Hip FLX
Femoral

66
Q

Vastus Group
Action:
Nerve:

A

Knee EXT
Femoral

67
Q

Sartorius
Action:
Nerve

Gracilis
Action:
Nerve:

A

Knee FLX and IR
femoral

Knee FLX and IR
obturator

Biomechanics Final (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions