Hips

Question 1

Angle of inclination

Answer 1

frontal plane angle b/w femoral neck and femoral shaft
normal is 125°

Question 2

Coxa vara

Answer 2

angle between shaft and neck is <110°
congenital or caused by injury
can cause shorter limb

Question 3

Coxa valga

Answer 3

angle between shaft and neck >135
cerebral palsy
can cause a long limb

Question 4

Compared to normal, in which scenario will the hip abductors have to produce more force to generate the same level of torque?

Answer 4

Coxa valga
moment arm is smaller vs a normal hip

Question 5

Femoral Torsion

Answer 5

Transverse plane angle btwn medial/lateral axis and the femoral neck
normal angles range from 8-20° in front of medial/lateral axis

Question 6

Femoral Anteversion

Answer 6

angle btwn horizontal and neck in transverse plane >20°
causes in-toeing because it positions the head better

Question 7

Femoral Retroversion

Answer 7

angle btwn horizontal and neck in transverse plane <8°
out-toeing

Question 8

Why does excessive anteversion or retroversion cause toe-in or toe-out gait?

Answer 8

you compensate to increase congruency of head with acetabulum

Question 9

Coxa valga and excessive anteversion are particularly common in individuals with cerebral palsy. Why?

Answer 9

decreased weight bearing causes the head to turn inwards

Question 10

Congruent position of hip

Answer 10

abduction
flexion @90°
ER

Question 11

Ligamentum Teres

Answer 11

runs between acetabulum and fovea
function is unknown in adults, can be taut in flex, add, IR
improves hip stability in newborns

Question 12

Acetabular Labrum

Answer 12

Restricts al motions
acts as a suction, grips and stabilizes femoral head
limited vascular supply

Question 13

Center Edge Angle

Answer 13

Degree to which the acetabulum covers the femoral head in frontal plane
25-35°

Question 14

Low center edge angle

Answer 14

indicates less contact area and greater joint stress
higher dislocation risk

Question 15

High center edge angle

Answer 15

Increases chance of impingement

Question 16

Acetabular Anteversion Angle

Answer 16

degree to which acetabulum faces anteriorly in transverse plane
20°
higher angle = subluxation, instability

Question 17

Hip joint capsule

Answer 17

resists flexion/extension
extremely strong, contributes to joint stability

thicker Ant & Sup
thinner post/inf

Question 18

Illiofemoral ligament

Answer 18

resists extension, ER, abduction
strongest
resists further hip extension when standing

Question 19

Pubofemoral ligament

Answer 19

resists abduction, extension, ER
blends into iliofemoral

Question 20

Ischiofemoral ligament

Answer 20

Moderate resistance to IR
Some resistance to extension & adduction
spiral formation, weakest formation

Question 21

Closed pack position of hip

Answer 21

hip extension
hip abduction
hip IR

stretches all capsular ligaments

Question 22

Degrees of freedom

Answer 22

3, axis is through the femoral head

Question 23

Sagittal plane

Answer 23

medial/lateral axis

Question 24

Frontal plane

Answer 24

A/P axis

Question 25

Transverse plane

Answer 25

Vertical axis most of axis is outside of femur

Question 26

Sagittal plane Pelvis on femur

Answer 26

anterior and posterior pelvic tilt

Question 27

Frontal plane Pelvis on femur

Answer 27

abduction/hip hike adduction/pelvic drop

Question 28

Transverse plane Pelvis on femur

Answer 28

internal rotation and external rotation

Question 29

Flexion/Extension movement of femoral head

Answer 29

SPIN, in closed chain or open chain

Question 30

Elevation of hip closed chain

Answer 30

Roll and slide are superior reference hip is the one technically going DOWN

Question 31

Hip drop closed chain

Answer 31

Roll and slide are inferior reference hip is the one technically going UP

Question 32

Hip Flexors

Answer 32

Anterior compartment illiopsoas, rectus femoris, sartorius, adductor longus, pectineus, TFL

Question 33

What happens to the moment arm of the iliopsoas when the muscle flexes to 90°?

Answer 33

moment arm increases, more force production is possible

Question 34

Prominent femur on pelvis flexor

Answer 34

iliopsoas

Question 35

Hip flexion often requires co-activation of hip flexor and abdominal muscles. Why?

Answer 35

the rectus abdominus helps to pull up in the same direction as the rectus femoris in contrast, psoas major and illacus will try to do flexion, causing anterior tilt and lordosis

Question 36

Hip extensors

Answer 36

posterior compartment gluteus max, hamstrings, adductor magnus

Question 37

Is hip extensor torque greater with the knee flexed or extended?

Answer 37

Flexing knee to 90° causes the hamstrings to decrease in length, decreasing the tension, overall decreasing how much force the hamstrings can produce

Question 38

Which hip extensors help control forward trunk flexion?

Answer 38

hamstring MA increase with increasing flexion glut max MA decreases with increasing flexion

Question 39

Hip abductors

Answer 39

gluteus medius, gluteus minimus, TFL

Question 40

Hip abductor muscle function

Answer 40

MA of abductors is 1/2 of MA from body weight. during standing, JRF is 2x body weight. Abductors case a negative torque, in contrast to body weight

Question 41

Greatest angle of hip abductor torque

Answer 41

10° earlier muscle activation of abductors means that less force will be produced from adductors. Important for hip stability

Question 42

Hip adductors

Answer 42

adductor group pectineus gracilis adductor magnus is a strong adductor in any position

Question 43

0-40° hip adductors

Answer 43

work as hip flexors in front of axis

Question 44

40-70° hip adductors

Answer 44

little torque production in line with axis

Question 45

70-100° hip adductors

Answer 45

work as hip extensors behind axis

Question 46

Hip Internal Rotators

Answer 46

no primary hip internal rotators glute med, glute min, TFL, pectineus, add longus/brevis

Question 47

Is gluteus medius a stronger internal rotator in neutral or in hip flexion?

Answer 47

changes orientation of moment arm from to parallel (not flexed) to perpendicular (flexed). Increases moment arm when hip is flexed

Question 48

Hip external rotators

Answer 48

gluteus maximus, piriformis, gemelli, obturator internus, quadratus femoris

Question 49

How does hip external rotation torque change with hip flexion at 90°?

Answer 49

G. max, piriformis = become IR obturator internus = stays ER, worse MA quadratus femoris, obturator externus = increase ER MA

Question 50

IR showed dramatic increase from ___ to _____

Answer 50

supine knee flexed to seated

Question 51

ER showed modest increase from ____ to ____

Answer 51

supine knee flexed to seated

Question 52

Is hip rotation PROM influenced by hip position?

Answer 52

less ROM from sitting vs prone major ligaments lax in flexion, meaning limitation would be capsular

Question 53

Femoroacetabular Impingement (FAI)

Answer 53

Large femoral neck or portion of acetabulum is hanging over head = congenital high center edge angle or acetabular retroversion coxa vara

Question 54

Hip labral tears

Answer 54

Chronic wear and tear traumatic injury FAI (increases stress on labrum) Coxa vara and valga Excessive anteversion or retroversion

Question 55

Hip osteoarthritis

Answer 55

breakdown of articular cartilage chronic wear and tear coxa valga or vara excessive anteversion or retroversion FAI labral tears increased contact stress at joint, caused by JRF, contact area, center edge/anteversion