SHOULDER Flashcards
1
Q
What makes up the shoulder complex?
A
Clavicle, scapula, humerus
2
Q
What are the 4 joints of the shoulder?
A
Glenohumeral, sternoclavicular, acromioclavicular, scapulothoracic
3
Q
How many degrees is the normal ROM of shoulder elevation?
A
180
4
Q
Which joint does 2/3 of the motion of shoulder elevation? Which one does 1/3?
A
2/3: GH, 1/3: ST
5
Q
What is the term for when active forces provide greater control than passive?
A
Dynamic stabilization
6
Q
Upper thoracic rotation occurs (ipsi/contra) laterally with shoulder elevation.
A
Ipsi
7
Q
What is the structural attachment between axial skeleton & shoulder?
A
SC joint
8
Q
What are the 3 degrees of freedom of SC joint?
A
Elevation/depression, protraction/retraction, anterior/posterior rotation
9
Q
What 2 structures does elevation/depression in SC joint occur between?
A
Disc & clavicle
10
Q
What 2 structures does protraction/retraction in SC joint occur between?
A
Disc & manubrium
11
Q
What 2 structures does anterior/posterior rotation in SC joint occur between?
A
Clavicle & 1st rib costocartilage
12
Q
SC joint is a 2 plane __________ joint.
A
Synovial
13
Q
Between these 2 joints, which one is superior & inferior? Medial clavicle & disc; medial clavicle with manubrium & 1st costal cartilage.
A
Superior: disc, inferior: manubrium & 1st costal cartilage
14
Q
With elevation & depression of SC joint, which structure rolls & glides on the disc?
A
Clavicle
15
Q
With protraction & retraction of SC joint, disc & clavicle roll & slide on which structure?
A
Manubrium
16
Q
What 2 ligaments both limit A/P translation? Which one is the primary one?
A
Anterior SC, posterior SC*
17
Q
What ligament limits elevation of lateral clavicle & counteracts superior pull of SCM & sternohyoid muscles?
A
Costoclavicular
18
Q
Which fibers of costoclavicular run laterally? Which run medially?
A
Laterally: anterior, medially: posterior
19
Q
Which ligament resists excessive depression of clavicle & superior gliding of clavicle on manubrium?
A
Interclavicular
20
Q
Interclavicular ligament is critical to protecting what structures that run behind clavicle?
A
Brachial plexus & subclavian artery
21
Q
For elevation of SC joint, the lateral end of clavicle moves upward & medial end rolls __________ & slides __________ on sternum.
A
Rolls superiorly, slides inferiorly
22
Q
How many degrees is SC joint elevation?
A
48
23
Q
For depression of SC joint, the lateral end of clavicle moves downward & medial end rolls __________ & slides __________ on sternum.
A
Rolls inferiorly, slides superiorly
24
Q
How many degrees is SC joint depression?
A
15
25
For protraction of SC joint, the lateral end of clavicle moves anteriorly & medial end rolls __________ & slides __________ on sternum.
Anteriorly for both
26
How many degrees is SC joint protraction?
15-20
27
For retraction of SC joint, the lateral end of clavicle moves posteriorly & medial end rolls __________ & slides __________ on sternum.
Posteriorly for both
28
How many degrees is SC joint retraction?
30
29
For posterior rotation of SC joint, the inferior surface faces __________.
Anteriorly
30
How many degrees is posterior rotation of SC joint?
50
31
How many degrees is anterior rotation of SC joint as it returns to neutral?
10
32
T/F: SC joint does not usually have degenerative changes or sublaxations.
F (dislocations instead of sublaxation)
33
What type of joint is the AC joint? How many degrees of freedom does it have?
Plane synovial, 3
34
What occurs when AC joint allows scap to rotate during arm movement?
Increases UE motion, positions glenoid beneath humeral head, maximizes scap contact to thorax
35
A vertical configuration of lateral clavicle with acromial facet makes it susceptible to ________ forces --> degeneration.
Shear
36
T/F: AC joint always includes a joint disc.
F
37
T/F: SC joint has stronger capsule than AC joint.
T
38
Which ligament resists opposing forces & is reinforced by delts & traps (dynamic stabilizers)?
Superior AC
39
T/F: Inferior AC ligament is not as strong as superior AC.
T
40
Which ligament firmly unites clavicle & scapula?
Coracoclavicular
41
Which ligament within the coracoclavicular ligament resists inferior forces?
Conoid
42
Which ligament within the coracoclavicular ligament resists posterior translation?
Trapezeoid
43
The critical role of coracoclavicular is to couple __________ clavicle rotation & scapula __________ rotation during arm elevation.
Posterior, upward
44
What motion of AC joint occurs around vertical axis & maintains contact of scap with thorax as clavicle protracts/retracts?
IR & ER
45
How many degrees of AC joint IR & ER?
20-35
46
What motion of AC joint occurs in oblique coronal axis & maintains scap with vertical curvature?
Anterior & posterior tilting
47
How many degrees is AC joint anterior & posterior tilting?
20-40
48
What motion of AC joint occurs in oblique AP axis & tilts glenoid fossa up & down?
Upward & downward rotation
49
How many degrees of AC joint upward rotation is there? How about downward?
Upward: 30, downward: 17
50
Trauma & degenerative changes of AC joint occurs with contact sports & falls on shoulders with arm __________.
Adducted
51
ST joint integrity depends on what other 2 joints?
SC & AC
52
Scapula rests ___" from midline between ribs 2-7.
2
53
In resting position, how many degrees is the scapula IR/protracted?
35-45
54
In resting position, how many degrees is the scapula tilted anteriorly?
10-15
55
In resting position, how many degrees is the scapula upwardly rotated?
5-10
56
___ degrees of ST joint upward rotation is required for arm elevation.
60
57
For upward/downward rotation of ST joint, there has to be SC joint _________ & _________ rotation.
Elevation, posterior
58
IR/ER of ST joint accompanies which motion of SC joint?
Protraction/retraction
59
Excessive internal rotation of ST joint results in what?
Scap winging
60
What are the 3 rotary motions ST joint can do? How about the 2 translatory ones?
Rotary: up/down, IR/ER, anterior/posterior tilting; Translatory: elevation/depression, protraction/retraction
61
Protraction/retraction of ST joint is equivalent to __________/___________.
Abduction/adduction
62
Which joint is a premier example of dynamic stabilization?
ST joint (muscles that attach to thorax & scap & scapulothoracic muscles)
63
What type of joint is GH joint?
Ball and socket synovial joint
64
GH joint has ___ rotary & ___ translatory degrees of freedom.
3 for both
65
T/F: Humeral head is smaller than glenoid fossa.
F (larger)
66
What is the proximal surface of GH?
Glenoid fossa (shallow concavity)
67
T/F: Glenoid fossa isn't always perpendicular to plane of scap.
T
68
What does it mean for glenoid fossa to be retroverted or anteverted?
Retroverted: more posterior, anteverted: more anterior
69
What is the distal surface of GH?
Humeral head
70
What 3 directions does the head face?
Medially, superiorly, posteriorly
71
How many degrees is the angle of inclination in GH joint?
130-150
72
How many degrees is the angle of torsion in GH joint?
30 degrees posteriorly
73
What is the angle of torsion measuring?
Between head & condyles
74
What is the angle of inclination measuring?
Between head & humeral shaft
75
What structure enhances fossa concavity by ~50%?
Glenoid labrum
76
What are other functions of glenoid labrum?
Resist humeral head translations, protect bony edges of fossa, minimize GH joint friction, dissipate joint contact forces
77
Glenoid labrum is attachment site for GH ligaments & what tendon?
Long head of biceps
78
Which motions make the GH capsule tighten?
Abduction, lateral rotation
79
The capsule is ___x surface area of humeral head.
2
80
In loose packed position of GH capsule (40 degrees abduction & 30 degrees horizontal adduction), how many cm of distraction possible?
2.5
81
GH capsule is vulnerable to __________ dislocations.
Anterior
82
Superior GH ligament helps to form rotator cuff interval & resist __________ & __________ translations of humeral head at 0 degrees abduction.
Anterior & inferior
83
Which ligament prevents any translation of humeral head from 0-60 abduction?
Middle GH
84
What are the 3 components of inferior GH ligament complex?
Anterior, posterior, axillary pouch
85
Which component of inferior GH ligament complex prevents ant/inf translation (ABD/ER)?
Anterior
86
Which component of inferior GH ligament complex prevents post/inf translation (ABD/IR)?
Posterior
87
Which component of inferior GH ligament complex prevents inf translation (ABD)?
Axillary
88
Which ligament has 2 bands & forms tunnel for long head of biceps to pass through?
Coracohumeral
89
The first band of coracohumeral ligament goes from base of coracoid to edge of supraspinatus tendon & __________ tubercle.
Greater
90
The second band of coracohumeral ligament goes from base of coracoid into subscapularis & __________ tubercle.
Lesser
91
What is the term for the vault formed over humeral head by coracoid, acromion, & coracoacromial ligament?
Coracoacromial arch
92
What 3 things does the subacromial space contain?
Subacromial bursa, rotator cuff tendons, tendon of long head of biceps
93
Coracoacromial arch protects subacromial structures & prevents _________ dislocation of humerus.
Superior
94
Coracoacromial arch is an area of impingement with __________ (muscle) & a narrowed joint space.
Supraspinatus
95
Which type of coracoacromial arch is most susceptible to impingement?
3
96
Which type of coracoacromial arch is most susceptible to superior dislocation?
4
97
In the coronal axis, how many degrees of flexion & extension can occur in GH joint?
Flexion: 120, extension: 50
98
Medial & lateral rotation of GH joint in long axis varies depending on what?
Arm elevation
99
In the AP axis, how many degrees of abduction & adduction can occur in GH joint?
90-120
100
When is abduction limited in GH joint?
In neutral or medial rotation by greater tubercle
101
___________ rotation is required for full abduction.
Lateral
102
In abduction & adduction in GH joint, there's (less/more) restriction of elevation in plane of scap.
Less
103
In GH joint elevation, humeral head slides ___________ & rolls __________.
Slides inferiorly, rolls superiorly
104
What counteracts gravity in GH joint?
Rotator interval capsule, capsular vacuum which creates negative pressure, lower glenoid & labrum tilt slightly upward, passive tension of supraspinatus
105
If the arm is loaded, __________ contracts.
Supraspinatus
106
With decreased rotator cuff function, there's an increase in __________ sublaxation.
Inferior
107
Which muscles provide the dynamic stabilization for GH joint?
Deltoid, rotator cuff
108
Deltoid is the prime mover for __________.
Abduction
109
Which part of deltoid does flexion?
Anterior
110
The majority of force from deltoid from rest position causes humerus to translate __________ since force vector of middle delt is larger parallel than perp.
Superiorly
111
What provides synergistic help to deltoid to produce desired rotation of humeral head?
Rotator cuff (supraspinatus, infraspinatus, teres minor, & subscap)
112
Rotator cuff __________ force component causes some rotation of humerus but also compresses head into fossa.
Perpendicular
113
Rotator cuff parallel force component offsets superior translatory force from deltoid by pulling it __________.
Inferiorly
114
Which muscles from rotator cuff help with lateral rotation to clear greater tubercle?
Infraspinatus, teres minor
115
Which rotator cuff muscle has large rotary component with large MA for abduction making it a prime mover in start of abduction?
Supraspinatus
116
Which ligament runs between greater & lesser tubercles & creates a hood for biceps brachii?
Transverse humeral
117
Which motions of the shoulder does bicep contribute to?
Flexion, abduction
118
What other functions does biceps brachii have?
Reinforce superior GH joint, center head, reduce vertical & anterior shear, tighten labrum
119
What is dynamic stabilization at any point of ROM in GH joint influenced by?
Force generated by primary movers, gravity, force created by muscular stabilizers, articular surface geometry, passive capsuloligamentous forces, friction, joint reaction forces
120
T/F: All forces in GH compress humeral head into fossa.
T
121
Joint reaction forces can reach ___-___x the weight of UE when arm is elevated.
9-10
122
Between which degrees of elevation does greatest shear force occur?
30-60
123
Which tendon is most vulnerable to impingement & damage?
Supraspinatus (superior or inferior surface)
124
Rotator cuff tears are common in 60+ years & pain is produced between 60-120 degrees which is known as what?
Painful arc
125
Scapulohumeral motion distributes motion between ___ joints to maintain glenoid fossa in optimal position for humeral head --> better joint congruency & decreased shear.
4
126
Scapulohumeral motion maintains good length-tension of humeral muscles to prevent _________ insufficiency as scap rotates up.
Active
127
The scapulohumeral rhythm is for __________ (flexion & abduction).
Elevation
128
How many degrees of elevation does ST joint do? How about GH?
ST: 60, GH: 120
129
What is the overall ratio of scapulohumeral rhythm?
2:1 GH:ST
130
For the first 30 deg of abduction or 60 deg of flexion, which joint does the most motion?
GH
131
What occurs after the first 30 deg of abduction or 60 deg of flexion?
ST & GH 1:1 --> ST motion completes (glenoid up & stable base) & GH finishes range
132
How do SC & AC joint contribute during ST motion of 60 degrees?
Clavicular elevation @ SC, posterior clavicular rotation @ AC
133
Which joint does the most motion during 30 degrees of abduction or 60 degrees of flexion?
GH
134
What occurs after the first 30 degrees of abduction or 60 degrees of flexion?
--> ST & GH 1:1 --> ST motion completes (glenoid up & stable base) & GH finishes range
135
How do SC & AC joint contribute during ST motion of 60 degrees?
- clavicular elevation @ SC
- posterior clavicular rotation @ AC
136
Which muscles upwardly rotate the scapula during clavicular elevation @ SC for scapulohumeral rhythm?
trap (upper & lower) & serratus anterior
137
Which ligament becomes taut during clavicular elevation @ SC for scapulohumeral rhythm?
costoclavicular
138
Which ligaments are taut during posterior clavicular rotation @ AC for scapulohumeral rhythm?
- conoid & trapezoid (coracoclavicular)
- costoclavicular
139
What does posterior clavicular rotation @ AC for scapulohumeral rhythm allow for?
Final phase of scap upward rotation & adjustment on ribcage
140
What do traps & serratus anterior produce & control during elevation?
tipping
141
Which parts of the deltoid work together for abduction?
ant & mid
142
What does the posterior deltoid do?
joint compression
143
Deltoid length-tension depends on which joint's motion?
ST
144
Supraspinatus has constant MA through ROM and has a larger one than deltoid for the first how many degrees of abduction?
60
145
Infra, teres minor, subscap have greater activity with what than abduction?
flexion
146
What 2 muscles elevate & downwardly rotate the scapula and can eccentrically stabilize during upward rotation?
rhomboids & levator scap
147
Which muscle does adduction, extension, medial rotation of humerus & adduction & depression of scap?
lat
148
Which portion of pec major depresses GH & shoulder complex?
sternal
149
Pec minor assists which 2 muscles by directly depressing scap through attachment to coracoid process?
- lat
- pec major
150
Which 2 muscles strongly synergistically adduct & depress the humerus?
teres major & rhomboids
151
GH joint: shoulder flexion/abduction includes what roll of humerus with what slide on glenoid?
- superior roll
- inferior slide
152
Shoulder flexion/abduction includes which 3 motions of the scapula?
- protraction
- elevation
- upward rotation
153
SC joint: shoulder flexion/abduction includes what where clavicle rolls & glides anterior on manubrium and what SC rotation with SC elevation?
- protraction
- posterior
154
AC joint: shoulder flexion/abduction includes what rotation of scap/acromion in relation to clavicle?
upward
155
GH joint: shoulder lowering/adduction includes what roll of humerus with what slide on glenoid?
- inferior roll
- superior slide
156
Shoulder lowering/adduction includes which 3 motions of the scapula?
- retraction
- depression
- downward rotation
157
SC joint: shoulder lowering/adduction includes what and what rotation with depression?
- retraction
- anterior
158
AC joint: shoulder lowering/adduction includes what rotation?
downward
