Hip Biomechanics Flashcards
(170 cards)
1
Q
What is normal hip flexion
A
0-120
2
Q
What is normal hip extension
A
0-20
3
Q
Is hip flexion done with the knee extended or flexed
A
Flexed
4
Q
Is hip extension done with the knee extended or flexed
A
Extended
5
Q
What does hip proper mean
A
The pelvis doesn’t move during hip motions
6
Q
What is normal hip abduction
A
0-45
7
Q
What is normal hip adduction
A
0-30
8
Q
What are the 2 joint muscles you have to take into account for in the sagittal plane (2)
A
- Rectus femoris
2. Hamstrings
9
Q
What are the 2 joint muscles you have to take into account for in the frontal plane (2)
A
- Gracilis
2. ITB
10
Q
What limits hip ABD
A
The gracilis
11
Q
What is IR of the hip with knee extended
A
0-55
12
Q
What is IR of the hip with knee flexed
A
0-45
13
Q
What is ER of the hip with the knee extended
A
0-55
14
Q
What is ER of the hip with the knee flexed
A
0-45
15
Q
What causes the decreased amount of hip IR/ER with the knee flexed
A
The posterior capsule is tension loaded limiting motion
16
Q
What is the function of a joint capsule
A
Increase joint congruity to eliminate shear forces
17
Q
What are the normal hip ranges during gait (4)
A
- Flexion: 30
- Extension: 10
- ADD/ABD: 5
- IR/ER: 5
18
Q
What is it called if ABD/ADD and IR/ER increase to 15-20
A
Circumduction
19
Q
True or False:
The hip has 3 degrees of freedom during gait
A
True
20
Q
How much hip flexion is needed to sit down/rise from a chair
A
106
21
Q
How much hip flexion is needed to ascend stairs
A
67
22
Q
How much hip flexion is needed to descend stairs
A
36
23
Q
Why do we need 106 degrees of hip flexion to sit down/rise from a chair
A
We are not able to get out of a chair with hip flexion at 90
24
Q
What are the arthrokinematic motions during ABD in OKC
A
Superior roll and inferior glide
25
What are the arthrokinematic motions during ADD in OKC
Inferior roll and superior glide
26
What are the arthrokinematic motions during IR in OKC
Anterior roll and posterior glide or medial roll and lateral glide
27
What are the arthrokinematic motions during ER in OKC
Posterior roll and anterior glide or lateral roll and medial glide
28
What are the arthrokinematic motions during flexion in OKC
Spin (best evidence supports this)
| Anterior roll and posterior glide
29
What are the arthrokinematic motions during extension in OKC
Spin (best evidence supports this)
| Posterior roll and anterior glide
30
What causes flexion and extension to be spin (4)
1. Depth of cavity
2. Labrum
3. Negative pressure of joint
4. Ligamentous capsule and stability
31
True or False:
| You do joint play to free up motion throughout the entire capsule for the hip
True
32
What does the hip equal
Femur
33
What does the pelvis equal
Os coxa
34
What bone are we talking about in OKC
Hip
35
What bone are we talking about in CKC
Pelvis
36
What hip motion does posterior tilting of the pelvis cause
Hip extension
37
What hip motion does anterior tilting of the pelvis cause
Hip flexion
38
What are the sagittal plane motions of the pelvis
Posterior and anterior tilting/tipping
39
What are the frontal plane motions of the pelvis
Hiking/elevation and dropping/depression
40
Why is elevation/depression of the pelvis considered hemipelvic motion
Because only one hemipelvis moves
41
What muscles causes right hip elevation
Right quadratus lumborum and left gluteus medius
42
What does contralateral hemipelvis elevation cause at the ipsilateral hip
ABD of ipsilateral hip
43
What does contralateral hemipelvis depression causes at the ipsilateral hip
ADD of ipsilateral hip
44
What is more common hemipelvic depression or elevation
Depression
45
What is hemipelvic depression called
Trendelenburg
46
When do you see hemipelvic elevation (3)
1. Foot drop
2. Leg length discrepancy
3. Poor hip flexor strength
47
What hip are you pivoting about or around for the transverse plane motions of the hip
The hip of the leg you are standing on
48
What motions occur in the transverse plane at the hip
Forward and backward rotation
49
What is left forward rotation equal to
Left hemipelvis forwardly rotating about or around the right hip
50
What is left backward rotation equal to
Left hemipelvis backwardly rotating about or around the right hip
51
What is left forward rotation of the hip in terms of IR/ER for both hips
Left: ER
Right: IR
52
What is left backward rotation of the hip in terms of IR/ER for both hips
Left: IR
Right: ER
53
Do you use anterior/posterior for rotation and the hip
Negative on that one ghost rider
54
Which way do the pelvis and lumbar spine move in OKC lumbopelvic rhythm
The same direction
55
What does lumbopelvic rhythm strive to do in the closed CKC
Keep the head and trunk upright
56
Which way do the pelvis and lumbar spine move in CKC lumbopelvic rhythm
Opposite directions
57
What is Janda's pelvic cross syndrome
Excessive anterior or posterior tilt of the pelvis
58
If you have anterior pelvic tilting in CKC what occurs at the lumbar spine
Lumbar extension
59
If you have psoterior pelvic tilting in CKC what occurs at the lumbar spine
Lumbar flexion
60
What is an adaptively lengthened muscle referred to as
A weak and inhibited muscle
61
What is an adaptively shortened muscle referred to as
A strong facilitated muscle
62
What is adaptively shortened and lengthened during anterior pelvic tilting in the CKC
Shortened: Hip flexors and erector spinae
Lengthened: Rectus abdominis and hamstrings
63
What is adaptively shortened and lengthened during posterior pelvic tilting in the CKC
Shortened: Rectus abdominis and hamstrings
Lengthened: Hip flexors and erector spinae
64
How much of the acetabulum do the pubis, ischium, and ilium make
Pubis: 1/5
ISchium: 2/5
Ilium: 2/5
65
When does full ossification of the acetabulum occur
15-25 years old
66
True or False:
| The acetabulum has a horseshoe shaped articular area
True
67
What type of cartilage makes up the labrum of the acetabulum
Fibrocartilaginous
68
Why is fibrocartilage good
It has the ability to heal
69
Where is the transverse acetabular ligament located
The inferior part of the acetabulum
70
What does the transverse acetabular ligament do (3)
1. Spans articular gap of acetabulum
2. Forms roof of tunnel
3. Provides support
71
Which way does the acetabulum face
Anterior, inferior, and lateral
72
What is the center edge angle
Reference point from the center of the femoral head vertical and then reference point to edge of the acetabulum
73
Which part of the acetabulum does the center edge angle go to
The boney part
74
What does the labrum attempt to do
Provide structure to the acetabulum
75
What are the 3 changes that occur to the acetabulum with age
1. Ossification of the articulation of the 3 bones of the pelvis
2. Decreased acetabular roundness (Wolff's Law)
3. Increased center edge angle
76
What does ossification of the 3 pelvic bones do
Increases central stability
77
What does decreased acetabular roundness do
Reduces co-aptation (mathcing) of femoral head and acetabulum
78
What does decreased co-aptation of the acetabulum cause
Decreased mobility over time but more stability
79
What does increased center edge angle cause
Increased superior stability due to Wolff's Law
80
True or False:
| the younger you are the more likely you are to dislocate the hip superiorly due to the decreased center edge angle
True
81
What is more spherical the acetabulum or the femoral head
Femoral head
82
how is the femoral head oriented
Anterior, medial, and superior
83
IS the femoral head and acetabulum a perfect match
Nope
84
Is the hip better for mobility or stability
Stability
85
How much congruency does the femoral head and acetabulum have
2/3
86
What does the ligamentum teres carry
Acetabular branch of obturator artey
87
Where does the ligamentum teres attach on the femoral head
Fovea Capitis
88
How do you measure the angle of inclination
Draw a line through the head of the femur out the fovea capitis then draw another line through the shaft of the femur
89
What does the angle of inclination contribute to
The normal valgus position of the knee
90
What is the angle of inclination during early infancy, adulthood, and elderly years
Early infancy: 150
Adulthood: 125
Elderly years: 120
91
Why does the angle of inclination change as we age
Due to compression (Wolff's Law)
92
What is considered coxa valga
Greater than 125
93
What is considered coxa vara
Less than 125
94
What does coxa valga cause (3)
1. Increase leg length producing hip adduction
2. Increases pre load to hip abductors
3. Decreases moment arm of abductors
95
Is there a force output change in the hip abductors with coxa valga and why
No because the increased preload and decreased moment arm balance each other out
96
What does coxa vara cause (5)
1. Decrease leg length
2. Relative hip abduction
3. Poor hip abductor length tension relationship
4. Impingement may limit abduction ROM
5. Stress concentration superior contact area
97
What is stress concentration superior contact area
There is less contact between the femoral head and the acetabulum
98
What does the stress concentration superior contact area cause
Less surface area to distribute force of the body weight through the femur putting patient at risk for early on set OA
99
What is more concerning coxa valga or coxa vara
Coxa vara
100
Is valga congenital or traumatic
Truly congenital
101
What are 2 ways to get coxa vara
1. Fracture
| 2. Slipped capital femoral epiphysis
102
Who is at greater risk of slipped capital femoral epiphysis
Adolescent males with a higher BMI
103
What is the angle of version or torsion angle
How far anterior or posterior the femoral head is compared to the femoral condyles which are in the frontal plane
104
How do you measure the torsion angle
Draw a reference line through the frontal plane that goes through the femoral condyles then draw another line through the greater trochanter, neck and femoral head
105
What is the normal range for the torsion angle
8-15
106
What causes the torsion angle
Fetal development
107
What is anterversion or medial femoral torsion
The femoral head is anterior to the frontal plane
108
How do you determine if someone has a congenital problem when it comes to torsion angle
Bilateral comparison
109
How much anterversion are we ideally born with
30 degrees
110
True or False:
If you are born with excessive femoral anteversion you will lose some of that anterversion but not enough to have a normal anterversion
True
111
How do you compensate excessive femoral anteversion
Internally rotate hip
112
What type of gait does excessive femoral anterversion cause if compensated or uncompensated
Compensated: Toe in gait
Uncompensated: Toe out gait
113
What happens to the femoral head if the excessive femoral anteversion is not compensated
A significant amount of the femoral head will be exposed anteriorly
114
True or False:
| The majority of people with excessive femoral anteversion will have the compensated toe in gate
True
115
What happens with excessive anteversion to improve congruency of the joint
Rotation
116
What is it considered if torsion angle is less than 8-15
Retroversion
117
What is exposed if there is retroversion
Head of the femur posteriorly
118
What happens with excessive retroversion to improve congruency of the joint
Rotation
119
What does compensated retroversion result in
Toe out gate
120
What is the position of most congruency of the hip
30 flexion and ABD and slight ER
121
Is the position of most congruency of the hip the open or closed pack position
Open pack even though that is normally not the case
122
Why is the position of most congruency the open pack position of the hip
The soft tissue of the hip is slackened
123
True or False:
| The open pack position of the hip is used for post hip dislocation immobilization
True
124
True or False:
| High compressive loads may be necessary to achieve maximum congruency
True
125
True or False:
| Going into the open pack position causes the soft tissue of the hip to uncoil
True
126
What tightens the hip ligaments
Extension
127
What causes a flexion contracture
Resting on the Y ligament for a long period of time
128
Why do people with flexion contractures rest on the Y ligament
Due to poor core strength
129
What is the closed pack position of the hip
Extension and IR
130
True or False:
| The inferior angulation of the acetabulum is less than the superior angulation of the femoral neck
True
131
What does the inferior angulation of the acetabulum being less than the superior angulation of the femoral neck result in
A significant portion of the head remains uncovered
132
What does a significant portion of the head remaining uncovered potentially lead to
Decreased superior stability
133
What happens because both the acetabulum and femoral neck face anteriorly
A significant portion of the anterior head is exposed
134
What does a significant portion of the anterior head being exposed do
Decreased anterior stability
135
True or False:
| Anterior dislocation of the hip can result in vascular compromise of femoral vessels or femoral nerve palsy
True
136
What will tension to the iliopsoas group do
Pull the lumbar curvature anteriorly increasing the lumbar lordosis
137
What happens if the iliacus is tight
Increased anterior pelvic tilt
138
What motion does the TFL cause
Flexion and IR
139
What does the TFL do if the hip is already flexed
ABD
140
What is the most important contribution of the TFL
Maintaining tension in the ITB to increase stability of femur
141
True or False:
| The ITB is considered to assist in relieving the femur or some of the tesile loads on the shaft
True
142
True or False:
| The TFL helps prevent bowing of the femur during single leg stance
True
143
How much ADD should the Ober's test get if ITB is normal
10
144
What type of activity occurs on the side of compression of a bone
Osteoblastic activity
145
What type of activity occurs on the side of tension of a bone
Osteoclastic activity
146
True or False:
| The gluteus medius is the deltoid of the hip
True
147
What do all fibers of the gluteus medius do
ABD hip
148
What do the anterior fibers of the gluteus medius do
Flexion and IR of hip
149
What do the posterior fibers of the gluteus medius do
Extension and ER of hip
150
What does gluteus medius weakness cause
Trendelenburg gait (hemipelvic depression of the contralateral side of gluteus medius)
151
What can a tight gluteus medius cause
Tronchanteric bursitis due to increased friction
152
What is more likely to happen weak or tight glutes medius
Weak
153
True or False:
| The peak isometric torque of the hip ADD exceeds that of the ABD
True
154
What is the only hip ADD to cross the knee
Gracilis
155
What does adaptive shortening of the hip ADDs causes
Hemipelvic depression and ADD
156
What does adaptively shortened ADDs of the hip move
The pelvis on the femur
157
True or False:
| There is no muscle with a primary function of hip medial rotation
True
158
What are the most significant muscles that contribute to IR of hip (2)
1. TFL
| 2. Gluteus medius
159
When does the piriformis cause hip IR
Hip flexion greater than 90
160
What are the 6 primary muscles that cause ER of hip
1. Obturator internus
2. Obturator externus
3. Superior gemellus
4. Inferior gemellus
5. Quadratus femoris
6. Piriformis
161
When does the piriformis cause ER of the hip
Hip flexion less than 90
162
How much of the superincumbent BW do each femur bear
Half
163
True or False:
| The magnitude of gravitational toques around each hip is identical but opposite directions
True
164
Is hip abductor muscle force required to maintain equilibrium of the hip in bilateral stance
Nope
165
How much of the BW does the femur bear in single leg stance
2/3 plus the weight of the unsupported limb
166
How much of the BW does the trunk make up
2/3
167
What is the equation for torque
T=F*MA
168
What is the compression force at the hip equal to
The body weight compression and the muscular force compression
169
What is responsible for absorbing the compression force at the hip
Cartilage
170
Read through all of the ABD force stuff in the notes cards are too hard to make
Ok
