Hip Biomechanics (2)

Question 1

What’s the function of the pelvis?

Answer 1

Supports abdominal contents

Question 2

What does the pelvis link?

Answer 2

Vertebral column to the lower limbs

Question 3

Where does the pelvis transmit forces from?

Answer 3

Lower limbs to vertebral column

Question 4

What are the 7 joints in the pelvis?

Answer 4

Lumbo-sacral

Sacroiliac (2)

Sacro-coccygeal

Symphysis pubis

Hip joints (2)

Question 5

What does the acetabulum consist of?

Answer 5

2/5 ilium

2/5 ischium

1/5 pubis

Question 6

What happens to the roundness of the acetabulum with age?

Answer 6

It decreases

Question 7

What is the orientation of the acetabulum?

Answer 7

Anterior lateral inferior

Question 8

What is the average angle of anteversion in males?

Answer 8

18.5°

Question 9

What is the average angle of anteversion in females?

Answer 9

21.5°

Question 10

What does a larger angle of the acetabulum equal?

Answer 10

Less stability (increase likelihood of anterior dislocation of head of the femur)

Question 11

What are the functions of the acetabulum?

Answer 11

Deepens socket to increase joint concavity

Grasps femoral head to maintain contact with acetabulum

May serve proprioceptive and pain sensitivity roles

Question 12

What is the center edge angle of the acetabulum?

Answer 12

Magnitude of the inferior orientation

Question 13

What is the average center edge angle for men?

Answer 13

38°

Question 14

What is the average center edge angle for women?

Answer 14

35°

Question 15

What is the range of the center edge angle?

Answer 15

22-42°

Question 16

What does a decrease in center edge angle indicate?

Answer 16

Decreased stability

Question 17

How long does center edge angle increase for?

Answer 17

Until skeletal maturity

Question 18

What is the average angle of inclination for the femoral head in the acetabulum?

Answer 18

126° (115-140°)

Question 19

What indicates coxa valga?

Answer 19

Angle > 150°

Question 20

What indicates coxa vara?

Answer 20

Angle <120°

Question 21

What is the clinical relevance of the Coxa valga?

Answer 21

Ipsilateral subtalar pronation

Ipsilateral genu recurvatum

Ipsilateral knee/hip flexion

Ipsilateral anterior pelvic rotation

Contralateral lumbar rotation

Contralateral subtalar supination or plantar flexion

Long ipsilateral leg

Lateral rotation of leg

Question 22

What is the clinical relevance of Coxa vara?

Answer 22

Contralateral subtalar pronation

Contralateral Genu recurvatum

Contralateral knee/hip flexion

Ipsilateral posterior pelvic tilt

Ipsilateral lumbar rotation

Ipsilateral subtalar supination or plantar flexion

Short ipsilateral leg

Question 23

What is the normal angle of torsion in infants?

Answer 23

40°

Question 24

What is the normal angle of torsion in an adult?

Answer 24

10-20°

Question 25

What is anteversion?

Answer 25

In toe (effects knees and feet)

Question 26

What is retroversion?

Answer 26

Out toeing (effects knees and feet)

Question 27

What are some clinical findings of anterversion?

Answer 27

Excessive hip IR Limited ER Squinting patella Lateral patellar subluxation

Question 28

What is the most common direction for acetabular dislocation?

Answer 28

Posterior (in an adducted and flexed posture)

Question 29

What is the thickeness of the hip joint capsule in the posterior inferior direction?

Answer 29

Thin and loose

Question 30

What is the femoral neck?

Answer 30

Intrascapular

Question 31

What is the greater and less trochanter?

Answer 31

Extrascalular

Question 32

What does the iliofemoral ligament limit?

Answer 32

Extension and ER

Question 33

What does the pubofemoral ligament limit?

Answer 33

Abduction Extension ER

Question 34

What does the ischiofemoral ligament limit?

Answer 34

Extension IR ER

Question 35

How much body weight do the hip joint, capsule, and ligaments support?

Answer 35

2/3

Question 36

What is the normal stance in the hip?

Answer 36

Hip joint neutral or slight extension

Question 37

How strong are the capsuloligamentous structures?

Answer 37

Strong enough to support stance without muscular support

Question 38

What is the function of the ligamentum teres?

Answer 38

Conduit for secondary blood and nerve supply (not for stability)

Question 39

What would absence of secondary blood supply to the head result in?

Answer 39

Increase risk of avascular necrosis

Question 40

Where is the greatest strength in trabecular patterns?

Answer 40

Areas where the major systems cross

Question 41

Where are the zones of weakness in trabecular patterns?

Answer 41

Thin trabeculae (no crossing) More prone to injury Susceptible to bending forces

Question 42

What is the normal AROM for hip flexion?

Answer 42

120-130°

Question 43

What is the normal AROM for hip extension?

Answer 43

10-20°

Question 44

What is the normal AROM for hip abduction?

Answer 44

40-45°

Question 45

What is the normal AROM for hip adduction?

Answer 45

20-30°

Question 46

What is the normal AROM for hip ER?

Answer 46

40-50°

Question 47

What is the normal AROM for hip IR?

Answer 47

35-45°

Question 48

What is the normal PROM for hip flexion?

Answer 48

120-135°

Question 49

What is the normal PROM for hip extension?

Answer 49

10-30°

Question 50

What is the normal PROM for hip abduction?

Answer 50

30-50°

Question 51

What is the normal PROM for hip adduction?

Answer 51

10-30°

Question 52

What is the normal PROM for hip ER?

Answer 52

45-60°

Question 53

What is the normal PROM for hip IR?

Answer 53

30-45°

Question 54

What is the required hip motion to ascend stairs?

Answer 54

40-67° flexion

Question 55

What is the required hip motion to put on pants?

Answer 55

90° flexion

Question 56

What is the required hip motion to place the foot on opposite thigh?

Answer 56

120° flexion 20° abduction 20° ER

Question 57

What is the minimum functional ROM for the hip?

Answer 57

90° flexion 20° abduction 0-20° IR/ER

Question 58

What occurs in a posterior tilt?

Answer 58

Hip extension

Question 59

What occurs in an anterior tilt?

Answer 59

Hip flexion

Question 60

What occurs in right hip/pelvic hiking?

Answer 60

(Contralateral) left hip abduction

Question 61

What occurs in right hip pelvic drop?

Answer 61

(Contralateral) left hip adduction

Question 62

What occurs in a forward pelvic rotation?

Answer 62

Hip IR of supporting limb

Question 63

What occurs in backward pelvic rotation?

Answer 63

Hip ER of supporting limb

Question 64

What is the normal lumbopelvic rhythm in the Sagittal plane?

Answer 64

90° hip flexion 45° lumbar flexion

Question 65

What is the normal lumbopelvic rhythm in the coronal plane?

Answer 65

Left hip abduction limited to 45°