Brainscape's Knowledge GenomeTM

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


See full index

PHTH 7202 Anatomy > Knee Kinesiology Lecture - Dr. Glenn, includes charts from Neumann > Flashcards

Knee Kinesiology Lecture - Dr. Glenn, includes charts from Neumann Flashcards

1
Q

PCL: Functions (2)

A
  1. Most fibers resist knee flexion (either excessive posterior translation of the tibia or anterior translation of the femur, or a combination thereof)
  2. Resists extremes of varus, valgus, and axial rotation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Does the axis of rotation in the knee also waver mediolaterally?

A

yes, and this causes knee braces to be less effective than we would think

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

MCL (and posterior-medial capsule): common MOI:

A

Common MOI:

  1. Valgus producing force with foot planted (eg “clip” in football)
  2. Severe hyperextension of the knee
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Posterior capsule, knee: Common MOI (2)

A
  1. Hyperextension or
  2. combined hyperextension with ER of the knee
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how does PCL usually get ruptured?

A

extreme hyperextension.

(even though PCL also usually resists flexion)

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

Which meniscus has most things attached to it and has the least freedom of motion?

A

the medial meniscus

(Lateral meniscus has very few things attached to it, so it is freer to move. Many people theorize that this makes it harder to injure than medial meniscus)

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

Importance of co-contraction of eccentric and concentric muscles in the lower extremity

A

Co-contractions in the LE is much more important than UE. To keep the joint working correctly, all the muscles must work together. Big problems can happen if some of them are not working well (like hamstrings in a squat, even if it is a small squat)

Hamstrings keep femur from going too far forward in squats

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

Posterior Capsule: Functions (3)

A
  1. Resists knee extension
  2. Oblique popliteal ligament resists knee ER
  3. Posterior-lateral capsule resists varus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Q- angle: what is it and what is normal?

A

Quadriceps Angle: Formed between (1) a line representing the resultant line of force of the quadriceps, made by conecting ta point near the ASIS to the midpoint of the patella, and (2) a line representing the long axis of the patellar tendon, made by connecting a point on the tiial tuberosity with the midpoint of the patella.

Normal is about 13-15 degrees (+ or 1 4.5 degrees).

Measuring it has been the most popular and simple clinical index for assessing the relative lteral pull of the quads on the patella.

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

is the ACL or PCL bigger?

A

PCL is bigger than the ACL

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

LCL: Common MOI (2)

A
  1. Varus-producing force with foot planted
  2. Severe hyperextension of the knee
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can the quadriceps rupture the ACL?

A

Quadriceps cause extension, so they are a muscle that can be responsible for overstressing the ACL. (Quadriceps is definitely one of the things that can rupture ACL). Pretty rare for Quad to rupture normal ACL. A reconstructed ACL is a different story, especially open chain extension during rehab!!! Very prohibited.

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

Varus Force, Knee: Secondary Restraint(s) (7 general)

A
  1. Arcuate complex (includes LCL, posterior-lateral capsule, popliteaus tendon, and acruate popliteal ligament)
  2. ITB
  3. Biceps femoris tendon
  4. Joint contact medially
  5. Compression of the medial meniscus
  6. ACL and PCL
  7. Gastrocnemius (lateral head)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Anterior Region of capsule: passive and active restraints

A

Connective Tissue Reinforcement (passive)

  1. patellar tendon
  2. patellar retniacular fibers

Muscular-Tendinous Reinforcement (active)

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

Screw home mechanism: as the knee is flexing from full extension, no matter whether it is OKC or CKC, what is the direction of rotation for the femur and tibia RELATIVE to EACH OTHER?

A

Femur externally rotates

Tibia internally rotates

(in CKC the femur moves more while the tibia is more fixed.

In OKC the tibia moves more while the femur is more fixed)

These movements add up to 10 degrees total relative rotation at the knee joint.

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

Is the medial or lateral retinaculum bigger?

A

Medial retinaculum is much bigger than lateral retinaculum.

Also: Medial knee is very powerful. Partly because we live in a little bit of genu valgum. Our activity encourages developing more genu valgum. Some of the largest ligaments in the body are here, except maybe some of the large spinal ligaments.

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

Fabella

A

An accessory sesamoid bone in the knee in the lateral head of the gastrocnemius (neumann) or in distal biceps femoris in some people.

You can see it in an x-ray

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

Posterior-Lateral Region of knee capsule: passive and active restraints

A

Connective Tissue Reinforcement:

  1. Arcuate poplitial ligament
  2. LCL

Muscular-Tendon Reinforcement:

  1. Tendon of the popliteus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the purposes of the menisci?

A
  1. Shock absorption
  2. Neumann book says they triple the contact surface

Normal walking increases contact force about 3x body weight.

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

How many facets does the patella have?

A

Five

We mostly talked about the medial, lateral and odd facet (next to the medial facet - most medial)

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

Base of patella is also known as _______

Apex of patella is also known as ______

A

superior pole

inferior pole

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

what is the “antagonist” muscle group for the PCL?

A

hamstrings

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

Why does the meniscus slide anterior during knee extension?

A

Menisci are pulled anteriorly because the tibia is moving anterior!!! (not the quads. Quads don’t substantially connect and do not dictate the movement of the meniscus. No magic with the quads)

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

Structures included in the Acruate complex: (4)

A
  1. LCL
  2. Posterior-lateral capsule
  3. Popliteus tendon
  4. Acruate popliteal ligament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is often considered the primary stabilizer of the knee.

A

PCL because it is rarely ever very lax

19
Q

What structure is considered the center of the knee?

A

PCL (in cross sections, etc)

20
Q

what is the evolute?

A

the instantaneous axis of rotation in the knee

(the axis of rotation moves as the knee rotates in the saggital plane)

21
Q

Three main knee compartments

A
  1. Medial
  2. Lateral
  3. Patellofemoral
23
Q

ACL, knee: Common MOI (4)

A
  1. Large valgus-producing force with the foot firmly planted
  2. Large, axial rotation torque applied to the knee (in either rotation direction), with the foot firmly planted
  3. Any combination of teh above, especially involving strong quad contraction with the knee in full or near-full extension
  4. Severe hyperextension of the knee
24
Q

Plica

A

Folds in the synovium.

We will see them on MRI.

All joints in the body have the potential to have a plica. The most common joint for it to be a problem and found is in the knee. When we are developing as an embryo, there are about 6 different places joint capsule grows from. Usually no problems. The seams can become thickened and it can cause problems. Just having one doesn’t mean it will be symptomatic.

26
Q

Valgus Force, Knee: Primary Restraint(s)

A

MCL, especially the superficial fibers

27
Q

when does screw home mechanism take place, and how much rotation happens?

A

It happens in 0-30 degrees of knee flexion

there is 10 degrees of rotation (NOT 30 degrees!)

28
Q

Discoid Meniscus

A

A discoid meniscus is like a intervertebral disk. It is solid all the way through, so is no joint surfaces touching. It is an anomaly that will cause big problems. Surgeons try to fix it, but it never works. It is a flat solid piece.

(A normal meniscus has a lateral collar and bevels/ramps to the middle. The meniscus doesn’t cover the middle of the joint. There is just joint surface there.)

29
Q

What muscle group is the “antagonist” to the ACL?

A

Quadriceps

30
Q

AAOS norm for knee flexion:

A

135 degrees

32
Q

During screw home as the knee is EXTENDING, no matter whether it is OKC or CKC, what is the direction of rotation for the femur and tibia RELATIVE to EACH OTHER?

A

Femur internally rotates

Tibia externally rotates

(in CKC the femur moves more while the tibia is more fixed.

In OKC the tibia moves more while the femur is more fixed)

These movements add up to 10 degrees total relative rotation at the knee joint.

33
Q

MCL (and posterior-medial capsule): functions

A

Functions:

  1. Resists valgus (abduction)
  2. Resists knee extension
  3. Resists extremes of axial rotation (especially knee external rotation)
35
Q

Varus Force, Knee: Primary Restraint(s)

A

LCL

35
Q

What is the difference between the patellar groove and patellar notch?

A

nothing

They are the saem thing

36
Q

When are most knee ligaments taut, lax?

A

Most ligaments are posterior to the axis of rotation os they are tight at full extension.

Generally 30-60 degrees of knee flexion, the big 4 ligaments are largely slack

Most if not all of our ligament stress tests will occur within this ROM when they are slack (so the non-targeted ligaments will be slack enough not to test them when you want to test only the target ligament).

37
Q

how does the meniscus usually move upon knee flexion and extension?

A

Usually it follows the tibia, but sometimes the lateral meniscus can be convinced to follow the lateral femoral condyle (such as in the last 30 degrees of extension - screw home)

38
Q

LCL: Functions (3)

A
  1. Resists varus (adduction)
  2. Resists knee extension
  3. Resists extremes of axial rotation
39
Q

are the medial and lateral compartments in the knee identical?

A

no. The medial compartment looks much bigger

40
Q

what is the “key” to unlock the screw home mechanism (the “key” to the lower extremities)?

A

Popliteus!

41
Q

Posterior Lateral Corner

A

I think Dr. Glenn said in cadaver lab when I asked him today:

  1. Popliteal Tendon
  2. Posterior Capsule
  3. Arcuate? ligament

He said for sure that it is a devistating injury and almost never happens in isolation. If we have a posterior lateral corner injury, other stuff is also injured badly. He said he woudn’t ask what is in posterior lateral corner this specifically.

From my lecture notes:

Posterior-lateral corner (Neumann doesn’t use this term, but it is a practical term used in orthopedics)

With a lot of knee surgeries a ligament tear is most commonly going to be the ACL. There can be injuries so severe that the posterior-lateral corner structures are so damaged and unstable that they do surgery here.

GET THE TERM POSTERIOR LATERAL CORNER. Look in Neumann to see what structures stabilize posterior lateral corner (they are labeled posterior-lateral stabilizers, not corner)

Structures in Neumann:

Connective Tissue Reinforcement:

Arcuate poplitial ligament
LCL

Muscular-Tendon Reinforcement:

Tendon of the popliteus

42
Q

TF: both collateral ligaments are taut upon knee extension and External (lateral) rotations of the tibia.

A

true

44
Q

A bone spur can also be called _______ or ________ (they all mean basically the same thing).

A

osteophyte

hypertrophic bone growth

45
Q

ACL: Functions (2)

A
  1. Most fibers resist extension (either excessive anterior translation of the tibia, posterior translation of teh femur, or a combination thereof)
  2. Resists extremes of varus, valgus, and axial rotation
46
Q

What is a standard veiw of how an ACL is torn?

A

Tibial or femoral rotation with an excessive valgus stress (not necessarily contact)

In athletics there are two maneuvers that every athlete does: Plant foot and cut to opposite side or ipsilateral side (side-step or cross-over step). It takes excessive force in this awkward position.

(Lack of muscular strength in LE is a big part of why women suffer ACL tears more.)

47
Q

Popliteus!

A
49
Q

Which meniscus is C-shaped? What is the other one shaped like?

A

Medial meniscus is C-shaped

I think the lateral meniscus os more O-shaped or something

50
Q

Medial Region of knee capsule: passive and active restraints

A

Connective Tissue Reinforcement:

  1. Medial Patellar retinacular fibers (often referred to as the medial patellofemoral ligament - MPFL)
  2. Medial collateral ligament
  3. Thickened fibers posterior-medially (often referred to as the posterior-medial capsule or the posterior oblique ligament)

Muscular-Tendon Reinforcement:

  1. Expansions from the tendon of the semimenbranosus
  2. Tendons of the sartorius, gracilis, and semitendinosus (so basically tendons of the pes anserine).
52
Q

PCL, knee: Common MOI (4)

A
  1. Falling on a fully flexed knee (with ankle fully plantar flexed) such that the proximal tibia first strikes the ground
  2. Any event that causes a forceful posterior translation of the tibia (ie “dashboard” injury) or anterior translation of the femur, expecially while the knee is flexed.
  3. Large axial rotation or valgus-varus applied torque oto the knee with the foot firmly planted, especially while the knee is flexed
  4. Severe hyperextension of the knee causing a large gapping of the posterior side of the joint
54
Q

Lateral Region of capsule: passive and active restraints

A

Connective Tissue Reinforcement:

  1. LCL
  2. Lateral patellar retinacular fibers
  3. ITB

Muscular-Tendon Reinforcement:

  1. Biceps Femoris
  2. Tendon of the popliteus
  3. Lateral head of the gastrocnemius
55
Q

Rotary Instability

A

We will talk about it in ortho lab. Cruciate ligament problem. Means tibia is unstable in multiple planes. Moving around an excessive amount in multiple planes.

56
Q

When is the patella 100% engaged in the patellar groove?

A

135 degrees of flexion (normal flexion)

57
Q

Posterior Region of knee capsule: passive and active restraints

A

Connective Tissue Reinforcement:

  1. Oblique popliteal ligament
  2. Arucate popliteal ligament

Muscular-Tendon Reinforcement:

  1. Popliteus
  2. Gastrocnemius
  3. Hamstrings, especially the tendon of the semimenbranosus
58
Q

Significanc of the meniscus horns

A

Horns are of meniscus are talked about in much more reverence than the other things that attach the meniscus to the tibia. Deliver nerve and vacular supply. IF we lose the horns we lose NERVE and vascular supply to meniscus. Embryonically, menisci grow from the horns. There used to be a belief that menisci could grow back if horns were left, so during menisectomy, the horns were left. Removal of menisci will accelerate development of OA.

59
Q

Valgus Force, Knee: Secondary Restraint(s) (7 general)

A
  1. Posterior-medial capsule (includes semimenbranosus tendon)
  2. ACL and PCL
  3. Joint contact laterally
  4. Compression of the lateral meniscus
  5. Medial retinacular fibers
  6. Pes anserine (tendons fo sartorius, gracilis, and semitendinosus)
  7. Gastrocnemius (medial head)
60
Q

Four ways to moderate compressive force (joint reaction force)

A
  1. Long bones are bending to help absorb force
  2. Eccentric muscle activation
  3. Hyaline cartilage
  4. Jointe congruity (when the joint needs to withstand the most force, then it will be the most congruent)
61
Q

what is the knee’s normal position in the frontal (coronal) plane?

A

a little genu valgum (about 5-10 degrees is normal)

PHTH 7202 Anatomy (7 decks)

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