General Principles of Biomechanics Flashcards
1
Q
Articulation of humeroradial joint
A
Distal end of humerus (capitulum) with concave oval facet of proximal radius
2
Q
Is the capsule of the elbow joint thick or thin
A
Thin
3
Q
the annulus fibrosis is composed of….
A
Collagen (Type 1) and fibrocartilage
4
Q
Shape of proximal end of humerus
A
Half a sphere
5
Q
Define boggy end feel
A
Edema, joint swelling
6
Q
Where does the first 30-60 degrees of elevation occur
A
Glenohumeral
7
Q
What is the acetabular fossa
A
center of acetabulum
8
Q
what ligament connects medial and lateral meniscus
A
Transverse ligament
9
Q
What is T2 MRI used for
A
Soft tissue structures (shows tissues with high water content)
10
Q
What does the quadrate ligament do
A
Reinforce inferior joint capsule
Maintains position of radial head in opposition to ulna
Limits amount of spin in supination and pronation
11
Q
what is the angle for coxa valga
A
Over 125
12
Q
When finger flexors are weak, what muscles substitute
A
Passive finger flexion by contraction of wrist extensors
13
Q
what is the Resistance in a lever system
A
the force that opposes movement
14
Q
What is T1 MRI used for
A
Bony anatomy
15
Q
Is the medial or lateral femoral condyle more inferior
A
Medial descends more inferiorly
16
Q
What is the direction of the proximal humerus
A
Retroverted 20-30 degrees
17
Q
Shape of ulnar collateral ligament
A
Triangle
18
Q
What happens when a concave surface moves on a convex surface
A
Same direction (anterior roll, anterior glide)
19
Q
orientation of the head of the femur
A
superior
anterior
medial
20
Q
A what type of joint is TMJ
A
synovial
21
Q
Define soft end feel
A
Soft tissue approximation
22
Q
What menisci is large and C shaped
A
Medial
23
Q
Three motions describing movement of one joint surface on another
A
Roll, glide, spin
24
Q
Inner surface of the labrum is lined with…
A
Articular cartilage
25
what is the acetabular fossa filled with
fat pad for shock absorption
26
THE ELBOW
.
27
Angle of femoral neck and what direction
anterior 10-15 degrees
28
What do the anterior and posterior radioulnar ligaments do
Strengthen radioulnar capsule
29
For accessory joint motion, what is better: interrater or intrarater reliability
Intrarater
30
The orientation of the glenoid fossaplaces true _______ at ______ anterior to frontal plane
true abduction at 30 degrees anterior to frontal plane
31
What is the main contributor to bony stability in the elbow
Trochlea (humerus) and trochlear fossa (ulna)
32
Why is the hip joint very stable
Bony anatomy as well as strength of ligaments and capsule
33
Arthrology of glenohumeral joint
Convex humeral head articulates with concave glenoid fossa
34
What does the ulnar collateral ligament do
Reinforces humeroradial joint medially
35
In the wrist, what is the convex concave relationship of the radius and carpals
Radius is biconcave to carpals
36
What covers articular surfaces of TMJ
dense fibrous cartilage (not hyaline)
37
the CMC joint is a ______ articulation
Saddle
38
What position does the annular ligament protect the radial head in
Semi-flexion (most unstable)
39
What’s the center of the head of the femur that is a depression
fovea capitis femoris
40
where is the effort in a second Class Lever
effort is farthest away from axis (axis-resistance-effort)
41
Define arthrokinematics
Movement between joint surfaces
42
What does PCL check
posterior displacement of the tibia in femur
43
Radial nerve distribution
Remainder of dorsum of hand not by median or ulnar
44
Functions of glenoid labrum
Lubrication
| Protection
45
What direction does ACL run
Oblique superiorly and laterally
46
On x-rays, what color do more dense structures appear
White
47
Two types of images on a MRI
T1
| T2
48
What does radial collateral ligament do
Reinforce humeroradial joint laterally
49
How many bands in the glenohumeral ligament
Three bands
50
Is the medial or later tibial condyle more stable
Medial is more stable = less mobile
Lateral is less stable = more mobile
51
Purpose of the labrum of the hip
Deepens acetabulum
52
Where does radial collateral ligament run
Lateral epicondyle —> annular ligament
53
Where does the transverse humeral ligament sit
Over the top of the bicipital groove
54
Where does the iliofemoral ligament run
both bands start at AIIS
medial runs to distal intertrochanteric line
lateral proximal disintertrochanteric line
55
Articulation of distal radioulnar joint
Convex ulna with concave radius
56
what’s the shape of the head of femur
two-thirds of a sphere
57
Define firm end feel (pathological)
Decreased elasticity, fibrosis of soft tissue
58
What is the extensors hood
fibrous mechanism on the dorsum of each finger that is a fibrous expansion of the extensor digitorum tendon
59
What does medial meniscus attach to
MCL
| fibrous capsule
60
In the proximal radioulnar joint, what is the shape of the radial head
Convex
61
Articulation of humeroulnar joint
Trochlea and trochlear notch
62
what covers the head of the femur
Articulation cartilage (except fovea capitis)
63
How does the convex-concave rule apply to the spine
convex rule at Atlanto-occipital joint
concave rule below second vertebrae
64
What shape is the hip labrum
Triangle
65
What ribs does the scapula sit over
2-7 ribs
66
What does the glenoid labrum attach to
Capsule superiorly and inferiorly
| Long head of biceps tendon superiorly
67
Function of collateral ligaments in hand
Tighten with flexion and voles fibers tighten with extension
68
Define rubbery end feel
Muscle spasm
69
what cervical joint is the yes joint
Atlanto-occipital
70
When pectoral is major is weak, what muscles substitute
Long head of biceps
Coracobrachialis
Anterior deltoid
71
Is the glenoid fossa shallow
Yes very shallow
72
What other ligament does the LCL run in the same direction as
PCL
73
What is the function of the transverse humeral ligament
Act as a retinaculum for long biceps tendon
74
what is a Second Class Lever
when two forces are applied on one side of an axis
75
In what direction is the shoulder capsule least supported and most lax
Inferirorly
76
Acetabulum orientation
Lateral
Inferior
Anterior
77
what is the volar plate
Thickening of the capsule
78
The elbow capsule is continuous medially with ——- and laterally with ———
Medial UCL
| lateral LCL
79
Direction MCL runs
oblique anteriorly and inferiorly
80
Where does the labrum attach
Bony rim of acetabulum
81
The inter surface of the annular ligament is lined with...
Fibrocartilage
82
Example of third Class Lever in body
Most muscles (elbow flexion)
83
Is the UCL or RCL stronger and why
UCL...RCL attaches to soft tissue structure (annular ligament)
84
what do the two atypical vertebrae allow for
increase AROM without compressing spinal cord, uncinate processes, and transverse foramen
85
Both of the articulations in the sternoclavicular joint are covered with
Fibrocartilage
86
Is the lateral meniscus smaller or larger than the medial meniscus
smaller
87
Define hyper mobility end feel
End feel at a later time than the other side
88
The coracohumeral ligament is taut with
External rotation
89
What position is the annular ligament most taut
Extremes of pronation and supination
90
What are CTs used for
```
Complex fractures
Facet dysfunction
Disc disease
Stenosis of spinal canal
IV foramen
```
91
What happens when convex surface moves on a concave surface
opposite direction (anterior roll, posterior slide)
92
Articulation of radiocarpal joint with CC
convex scaphoid and lunate
| concave radius
93
Purpose of extensor hood
Assist with extension of the PIP and DIP joints
94
Define firm end feel
Capsular/ligamentous stretching
95
what joint is the no joint
atlanto-axial
96
Where are uncinate joints and what do they do
Found at C3-C7 and limit lateral cervical movement
97
What is encircled with the annular ligament
Radial head
98
What are x-rays best used for
Dysfunction/disease of bones (not soft tissue)
99
Define osteokinematics
Movement between two bones
100
When hip extensors are weak, what muscles sub
Lower back extensors
Adductor magnus
Quadratics lumborum
101
is the acetabular fossa articulating
no
102
When hip flexors are weak, what muscles sub
Lower abdominals
Lower obliques
Hip adductors
Lattisimus dorsi
103
What does the clavicle link
Manubrium to acromion
104
What kind of joint is the tibiofemoral joint
Synovial hinge with two degrees of freedom
105
In shoulder elevation, what happens at 75 degrees in the GH
External rotation
106
for the screw ho,e mechanism, what happens at the elbow
Elbow flexion: ulna ER (supinate)
Elbow extension: ulna IR (pronates)
107
Where does ACL attach
anterior intercondylar fossa of tibia and to femur at medial aspect of lateral condyle
108
CC for proximal tibuofemoral joint
tibia is convex
fibular is concave
109
Function of radial collateral and ulnar collateral ligaments
RCL limit ulnar deviation
UCL limit radial deviation
110
At 60 degrees of elevation in the shoulder, where does movement occur
60 degrees
111
What is nucleus purposis made of
water and proteoglycans it’s minimal collagen
112
what is a third Class Lever
when two forces are applied on one side of an axis
113
what other ligament does MCL run with in the same direction
ACL
114
when do the menisci follow the tibia
flexion/extension
115
What does PCL attach to
posterior intercondylar fossa of tibia and on lateral surface of femoral medial condyle
116
What does LCL prevent
ER and stability against varus forces
117
what muscle attaches to medial meniscus
semimembranosus
118
What positions are the MCL taut and slackened with
taut extension
slackened flexion
119
CC relationship between ulna and triquetrum
Ulna is convex, triquetrum concave
120
when do menisci follow the femoral condyles
internal/external rotation
121
what does ACL check
forward gliding of tibia on femur
limits IR of tibia during flexion as it twists around PCL
122
Rules of 3:
Spinous process of T1-T3 even with transverse process of same level
T4-T6 SPs one half level below TP
T7-T9 SPs one full level below TP
T10 full level below
T11 one-half level below
T12 level
123
Primary function of coracohumeral ligament
Reinforce biceps tendon
Reinforce superior capsule
Prevent caudal dislocation of humerus
124
Where does the coracohumeral ligament attach
Base of coracoid process to greater and lesser tubercle of humerus
125
Where does the MCL knee run
Medial aspect of medial femoral condyle to upper end of tibia
126
Both bands of the iliofemoral ligament are taut with
Extension and ER
127
where does LCL knee run
Lateral femoral condyle to head of fibula
128
Shape of radial collateral ligament
Fan
129
What is the articulate surface of the humerus covered in
Hyaline cartilage
130
What is the coxa vara angle
Less than 115
131
What ligament is the Y ligament
Iliofemoral Ligament
132
Define hard end feel
When bone and cartilage meet
133
What type of joint is the hip joint
Synovial joint
134
what is excessive anteversion
Over 25-30 degrees
135
what is a First Class Lever
when two forces are applied on either side of an axis
136
what does MCL prevent
prevents ER and forces against valgus forces
137
when hip abductors are weak, what muscles substitute
Lateral trunk muscles/tensor fascia latae
138
What are the functions of the menisci
```
Deepens fossa of tibia
Increases congruency of tibia and femur
Provides stability to tibiofemoral joint
Provides shock absorption and lubrication to knee
Reduces friction during movement
Improves weight distribution
```
139
Direction of the LCL run
Inferior and posterior
140
Define empty end feel
Loose, then very hard, associated with muscle guarding or patient avoiding painful range
141
Direction of the glenoid fossa of the scapula
Anterior
Laterally
Superiorly
142
What is the purpose of the glenohumeral ligament
Reinforce anterior glenohumeral capsule
143
In the distal femur, what is the shape of the femoral condyles
Spiral
144
What’s the normal angle of inclination for the head of the femur
115-125
145
Median nerve distribution
Remainder of palmar surface not inner gated by ulnar
Dorsal portions of 2, 3, and lateral half of 4
146
The ulnar collateral ligament provides strong resistance to _____ forces
Valgus
147
Why does ER occur at 75 degrees of elevation in the shoulder
Prevents compression of greater tubercle against the acromion
148
Where does the annular ligament attach
Medial ulna
149
What is the glenoid labrum
Fibrocartilaginous ring that deepens glenoid fossa
150
Excessive retroversion angle
Less than 10 degrees
151
Arthrology of sternoclavicular joint
Convex SI
concave AP clavicle
articulates with opposite sternum
152
The three normal end feels
Soft
Firm
Hard
153
Where does the capsule of the shoulder attach
Medially to glenoid margin
| Laterally to humeral anatomical neck
154
What rule describes the relationship between arthrokinematics and osteokinematics
Convex-concave rule
155
Where does the coracoacromial ligament run
Coracoid to acromion
156
example in human body of First Class Lever
contraction of triceps at elbow joint
157
What does the annular ligament don
Protects radial head
158
Ulnar nerve distribution
Hypothenar region (palmar and dorsal)
Pinky 5th
Medial half of 4th
159
when shoulder abductors are weakened, what muscles substitute for shoulder motion
Scapular stabilizers
160
What direction does PCL run
Obliquely medially and anteriorly-superiorly
161
what is the Effort in a lever system
the force that attempts to cause movement
162
What is computed tomography (CT)
Plain x-ray slices that are enhanced by a computer to improve resolution
163
Does the LCL attach to the capsule
no
164
What is the hip labrum made of
Fibrocartilage
165
Shape of coracoacromial ligament
Triangle
166
How many atypical cervical vertebrae are there
2
167
where is the effort in a third Class Lever
next to the axis (axis-effort-resistance)
168
example of second Class Lever in body
toe raise
169
What does the radiate do
Stabilize hand for any impact
170
what is the screw home mechanism in the knee
5 degrees of tibial ER which occurs during terminal extension
