hip

Question 1

3 DOF (rotations)

Answer 1

Flex/ext

Abd/add

IR/ER

Question 2

3 DOF arthrokinematic (translations)

Answer 2

Ant/post

Sup/Inf

Traction/compression

Question 3

Version

Answer 3

Angle of head femur with respect to shaft in the transverse plane

Question 4

Angle of inclination

Answer 4

Angle between head & neck and shaft femur in frontal plane

Question 5

Alpha angle

Answer 5

Size between femoral head with respect to acetabulum

Question 6

Coxa vera

Answer 6

Hip bends inward (genu valgum)

<125 degrees

Question 7

Coxa valga

Answer 7

Hip bends upwards (genu varum)

> 125 degrees

Question 8

Range normal values for angle inclination:
Infants
Adults
Elderly

Answer 8

Infants: 165-170
Adults: 125
Elderly: <120

Decreases 2-8 degrees per yr

Question 9

Why does angle inclination dec?

Answer 9

Gravity

Pelvic width (women)

Puberty

Wt bearing

Question 10

Femur lat side (convex) resists what type of load?

Answer 10

Traction

Question 11

Femur med side (concave) resists what type of load?

Answer 11

Compression

Question 12

What is the effect of weight-bearing on the femoral shaft and neck?

Answer 12

Traction, compression

Inc angle inclination, dec bending mvt

Coxa valga dec bending moment of femur

Coxa vera inc bending moment (inc moment arm = risk for fracture)

Question 13

Trabecular configuration of the proximal femur main system:

Answer 13

Arcuate bundle: resists bending moment

Vertical bundle: resists compressive moment

Loc: head neck femur

Question 14

Trabecular configuration of the proximal femur accessory system:

Answer 14

Reinforces muscle attachment sites

First & second bundle

Loc: between neck shaft (greater trochanter)

Question 15

What are the effects of femoral inclination on bending moment?

Answer 15

Inc angle inclination, dec bending moment —> dec risk fracture (Coxa valga)

Question 16

Coxa vera trade off

Answer 16

Favors joint stability

Inc risk hip fracture (inc bending moment)

(Hip abd force= more advantageous)

(Dec func length)

Question 17

Coxa valga trade off

Answer 17

Favors dislocation

Dec risk fracture (dec bending moment)

(Hip abd force= dec mechanical advantage)

(Inc func length)

Question 18

Version

Answer 18

Twist of femoral shaft

Bisects head neck femur and frontal plane

(Typically viewed from above)

Question 19

Angle anteversion normal range

Answer 19

Range: 8-30 degrees

Avg: 15 degrees

Question 20

Excessive femoral anteversion

Answer 20

> 30 degrees

Neck points anteriorly

Question 21

Retroversion

Answer 21

<15 degrees (approaching 0 degrees)

Goes below frontal plane

Neck points medially

Question 22

What is the compensation for excessive anteversion?

Answer 22

In toeing (excessive IR)

Question 23

What are the mechanical consequences excessive femoral anteversion? (structure-func rel)

Answer 23

Inc femoral anteversion

Dec moment arm abd

Restored by IR hip

Question 24

What are the mechanical consequences excessive femoral anteversion?

Answer 24

Frontal plane: dec abd moment arm

Transverse plane: in toeing

Question 25

Pincer impingement

Answer 25

Bony growth extends roof acetabulum

Question 26

Cam impingement

Answer 26

Alpha angle measures how spherical and large head of femur is

Question 27

Cam deformity and pathological cam deformity ranges

Answer 27

Cam deformity: >60 degrees Pathological: >80 degrees \-> more severe and causes dysfunction

Question 28

Acetabular angle of opening in transverse and frontal plane are:

Answer 28

Version Center edge angle

Question 29

Acetabular center edge angle, range

Answer 29

Degree to which acetabulum covers femoral head Angle: line down ilium-center femoral head and line between edge lat acetabulum and center of femoral head 35-40 degrees

Question 30

Low CE angle means

Answer 30

Reduced acetabular coverage of femoral head (greater risk dislocation) (less contact area w/in joint)

Question 31

High CE angle means

Answer 31

Overcoverage —> impingement Eg: Osteoarthritis

Question 32

Acetabular anteversion range

Answer 32

10-30 degrees

Question 33

Excessive acetabular anteversion consequences

Answer 33

Hip vulnerable to ant subluxation/dislocation

Question 34

Retroverted acetabular anteversion consequences

Answer 34

Impingement (stability) Bc angle = close to 0/ is negative (acetabulum faces lat)

Question 35

Iliofemoral lig

Answer 35

Y lig (limits hyperext) Resists end-range hip ext Acts synergistically with iliopsoas (passively)

Question 36

Pubofemoral lig

Answer 36

Limits hip abd, ext and ER

Question 37

Ischiofemoral lig

Answer 37

Superficial fibers: limit IR, esp slight abduction Deep fibers: limit and range hip flexion

Question 38

T/F flexion spine goes with ant tilt

Answer 38

T

Question 39

Answer 39

Closed chain (Standing leg=reference leg)

Question 40

Non WB

Answer 40

Convex on concave

Question 41

WB

Answer 41

Concave on convex

Question 42

Synergist of ant tilt

Answer 42

Hip flexors: iliopsoas, sartorius, erector spinae

Question 43

Synergist post tilt

Answer 43

Hip ext: rectus abdominis, external oblique, gluteus maximus, hamstrings

Question 44

Abdominal ex

Answer 44

Straight leg raise

Question 45

Answer 45

Lumbar ext oppose post tilt (ant tilt:arch back) Greater stretch hamstrings

Question 46

Answer 46

Add longus as extensor: flexion (secondary ext) Add longus as flexor: ext (secondary flex)

Question 47

What are the best hip flexors?

Answer 47

Longest moment arm

Question 48

Answer 48

Hip

Question 49

Answer 49

MA change w/ hip position

Question 50

End feels hip movement

Answer 50

Musc = springy Ligament = firm