Shoulder Arthrology Flashcards
(160 cards)
1
Q
What is the articulation of the sternoclavicular (SC) joint?
A
Clavicle is like a strut holding the scapula
2
Q
The acromioclavicular (AC) joint attaches the _____ to _____.
A
Scapula; Clavicle
3
Q
What is considered to not be a true joint?
A
The scapulothoracic joint
4
Q
What describes an interface between bones where movements are linked to the movements at the SC and AC joints?
A
The Scapulothoracic joint
5
Q
In the scapulothoracic joint what provides the base for the GH joint?
A
The position of the scapula
6
Q
What is the most distal and mobile portion of the whole shoulder complex?
A
The glenohumeral joint
7
Q
What decreases the effectiveness of the entire UE?
A
Weakness, painful or unstable links
8
Q
Elevation is what kind of movement?
A
Superior slide
9
Q
Depression is what kind of movement?
A
Inferior slide
10
Q
Protraction is what kind of movement?
A
Medial border slides anterior and lateral
11
Q
Retraction is what kind of movement?
A
Posterior and Medial
12
Q
Upward rotation is what kind of movement?
A
- Inferior angle rotates superior and lateral direction
- Glenoid fossa faces upwards (UE elevation)
13
Q
What makes up the sternoclavicular joint?
A
- Medial end of the clavicle
- Clavicular facet on the sternum
- Superior border of the cartilage of the first rib
14
Q
What links the axial and appendicular skeleton?
A
The basilar joint of the UE
15
Q
What joint has extensive periarticular tissue?
A
Sternoclavicular
16
Q
What kind of joint is the SC joint?
A
Irregular saddle shape
17
Q
What is the arthrokinematic movement of the SC joint?
A
Convex on Concave (with the sternal facet reciprocally shaped)
18
Q
The longitudinal diameters of the SC joint extend roughly in the _____ plane between the superior and inferior points of the articular surfaces.
A
Frontal
19
Q
The transverse diameters of the SC joint extend roughly in the _____ plane between the anterior and posterior points of the articular surfaces.
A
Transverse
20
Q
What helps to reinforce the capsule at the SC joint?
A
The anterior and posterior SC ligaments
21
Q
Where is the interclavicular ligament located?
A
Between the two clavicles
22
Q
Where is the costoclavicular ligament located?
A
Between the clavicle and the costal cartilage of the rib below
23
Q
What percentage of people have an articular disc at the SC joint?
A
50%
24
Q
What muscles are associated with the SC joint?
A
- SCM
- Sternothyroid
- Sternohyoid
- Subclavius
25
How many degrees of freedom does the SC joint have and what are they?
- 3 degrees of freedom
- Sagittal
- Frontal
- Horizontal
26
What motions does the SC joint produce?
- Elevation/ Depression
- Protraction/ Retraction
- Rotation
27
What is the goal of the SC joint?
To place the scapula in the optimal position for the head of the humerus
28
If you move the GH joint you will ultimately move what other joint in combination?
SC joint
29
The clavicle will rotate in how many degrees of freedom with UE elevation?
All 3
30
What plane is elevation and depression in at the SC joint?
Generally parallel to the frontal plane
31
What is the axis of elevation and depression at the SC joint?
Near anterior-posterior
32
How many degrees of elevation and depression does the SC joint get?
- 35 to 45 degrees of elevation
- 10 degrees of depression
33
What are the arthrokinematics of elevation of the clavicle at the SC joint?
- Convex surface rolls superiorly and slides inferiorly
- Costoclavicular ligament will stretch and limit motion
34
What are the arthrokinematics of depression of the clavicle at the SC joint?
- Convex surface rolls inferiorly and slides superiorly
- Interclavicular ligament and superior portion of the capsule will stretch
35
The arthrokinematics of elevation and depression at the SC joint occur along what diameter?
Longitudinal
36
What plane is protraction and retraction in at the SC joint?
Occurs nearly parallel to the horizontal plane
37
What is the axis of protraction and retraction at the SC joint?
Vertical
38
How many degrees of protraction and retraction does the SC joint get?
15-30 degrees in each direction
39
The arthrokinematics of protraction and retraction at the SC joint occur along what diameter?
Transverse
40
What are the arthrokinematics of retraction of the clavicle at the SC joint?
- Concave surface of clavicle rolls and slides posteriorly on convex surface of sternum
- Stretches anterior costoclavicular ligament and anterior capsule
41
What are the arthrokinematics of protraction of the clavicle at the SC joint?
- Occurs in an anterior direction
- Stretches posterior costoclavicular ligament and posterior capsule
- Involves reaching forward
42
Axial (longitudinal) rotation of the clavicle at the SC joint is done at the bones _____ axis?
Longitudinal
43
When someone elevates their UE how much does the clavicle posteriorly rotate?
20-35 degrees
(as the UE returns the clavicle returns)
44
When talking about axial rotation of the clavicle the spin of its sternal end is relative to what?
The lateral surface of the articular disc
45
Axial rotation of the clavicle can not be preformed when the arm is in what position?
Resting at the side
46
Axial rotation of the clavicle is linked with the overall kinematic motions of what?
Flexion and Abduction
47
What makes up the acromioclavicular joint?
- The lateral end of the clavicle
- The acromion of the scapula
48
The clavicular facet on the acromion faces what direction?
Medial and slightly superior
49
Are articular discs present in the AC joint?
Articular discs of varying forms present in most AC joints
50
What is the capsule at the AC joint reinforced by?
By the superior and inferior AC ligaments
51
What is the extrinsic stability for the AC joint?
Coracoclavicular ligament
52
The coracoclavicular ligament is made up of two parts that branch from the coracoid process to the clavicle, what are they?
- Trapezoid ligament
- Conoid ligament
53
How many degrees of freedom are found at the AC joint?
3 degrees of freedom
54
What is the primary motion of the AC joint?
Upward and downward rotation
55
What is the secondary motion of the AC joint?
Rotational adjustment motions - to fine tune the position of the scapula in the horizontal and sagittal planes
56
Upward rotation of the scapula at the AC swings _____ and _____ relative to the end of the clavicle.
Upward; Outward
57
How many degrees of upward rotation do we get at the AC joint?
Up to 30 degrees
58
Downward rotation of the scapula at the AC joint returns the scapula to what?
Anatomical position
59
What plane is downward rotation at the AC joint preformed in?
Frontal plane depicted - but really the scapular plane
60
Pivoting or twisting type motions of the scapula around the lateral end of the clavicle at the AC joint are considered what kind of motions?
Rotational adjustment
61
Rotational adjustment motions help to optimally align the scapula against what?
The thorax
62
The horizontal plane rotational adjustment motions of the AC joint sit on what axis and produce what movements?
- A vertical axis
- Medial border moves away and creates internal rotation of the glenoid fossa
63
The sagittal plane rotational adjustment motions of the AC joint sit on what axis and produce what movements?
- Medial-lateral axis
- Inferior angle pivots away and creates an anterior tilt or reverse a posterior tilt
64
What happens at the AC joint during protraction?
The AC joint internally rotates in the horizontal plane and helps align the anterior surface of the scapula with the thorax curved surface
65
Elevation or shrugging creates a _____ tilt.
Anterior
66
What joint is considered not to be a true joint?
Scapulothoracic joint
67
Why is the scapulothoracic joint not considered a true joint?
It does not have direct contact because it is separated by laters of muscles (the subscapularis, serratus anterior, and erector spinae)
68
The scapula is seated in between what ribs?
The 2nd and 7th ribs
69
Where is the medial border of the scapula located?
6 cm lateral to the spine
70
What degree of anterior tilt, upward rotation, and internal rotation is found at the scapulothoracic joint?
- 10 degrees of anterior tilt
- 5-10 degrees of upward rotation
- 30-40 degrees of internal rotation
71
UE ROM is largely dependent on what?
Scapular motion
72
Elevation and depression as a whole are combinations of what joints?
Composite SC and AC
73
Protraction and retraction is a summation of what motions?
Horizontal motions at both the SC and AC
74
For protraction and retraction movements what does each joint involved focus on?
- SC joint focuses on the protraction aspect
- AC joint focuses on the internal rotation
75
What supports/ stabilizes the head of the humerus during upward and downward rotation?
The glenoid fossa
76
Upward rotation is the summation of _____ elevation and SC/ scapular upward rotation.
Clavicular
77
What degrees of upward rotation do we get at the scapula?
60 degrees
78
What makes up the glenohumeral joint?
- Large convex head
- Shallow concavity (glenoid fossa)
79
The head of the humerus is positioned how?
Medially, superiorly, and posteriorly (normal retroversion)
80
How would you describe the fibrous capsule?
- Capsule that branches from the rim of the glenoid fossa to the anatomical neck of the humerus
- It is loose fitting, thin and expandable
- It allows for mobility, and is reinforced by external ligaments
81
In the anatomical position, is the inferior portion of the capsule slackened or taught?
Slackened - called the axillary pouch
82
What lines the inner wall of the GH joint?
Synovial membrane
83
There is an extension of the synovial membrane that lines the intracapsular portion of the tendon of the long head of the biceps and exits into the _____ _____.
Intertubercule groove
84
The head of the humerus and the glenoid fossa is line with what?
Articular cartilage
85
What amount of space is present in the GH joint?
A volume 2 times the size of the humeral head
86
What are the 3 primary stabilizers of the GH joint?
- A passive tension that is in the embedded ligaments
- Active forces that are produced by the local muscles (specifically the rotator cuff)
- Long head of the biceps tendon crosses superior over the head of the humerus to help stabilize too
87
The GH capsular ligaments are fibrous connective tissues made up of interlacing collagen fibers that limit what motion?
Extremes of rotation and translation
87
The superior ligament of the GH capsule resists what motions?
Exterior rotation and inferior and anterior translations of the humeral head
88
The middle ligament of the GH capsule does what?
- Stabilizes most motions
- Resists anterior translation of the humeral head, especially in 45 to 90 degrees of abduction and extremes of external rotation
89
Where is the middle ligament of the GH capsule slackened?
In internal rotation (blends with the subscapularis)
90
The inferior GH ligament has 3 portions (bands), in what position are they taught in?
- All: Taught in 90 degrees of abduction
- Axillary: combined with anterior-posterior and inferior translations
- Anterior: and full external rotation; anterior translation of humeral head
- Posterior: and full internal rotation
91
What do the inferior bands of the GH capsule support?
- Hammock like so it supports the suspended humeral head
92
What do the inferior bands of the GH capsule resist?
Inferior and anterior-posterior translation
93
What is the strongest and thickest part of the GH capsule?
Anterior
94
Where does the coracohumeral ligament run?
From the coracoid process to the greater tubercle
95
What does the coracohumeral ligament blend with?
The superior capsule and supraspinatus tendon
96
Where is the coracohumeral ligament taught?
In anatomical position
97
What does the coracohumeral ligament resist?
Inferior translation of the humeral head and external rotation
98
What is being described when someone says: its is a significant structural support to the capsule, it blends with the capsule, the belly of the muscles are close to the joint, and it protects and is an active stabilizer.
The rotator cuff
99
Where does the subscapularis sit in reference to the capsule?
Anterior
100
Where do the supraspinatus, infraspinatus, and teres minor sit in reference to the capsule?
Superior and posterior
101
What is the thickest muscle in the rotator cuff?
Subscapularis
102
Where is the most common site for a dislocation?
Rotator cuff interval - inferior and supraspinatus/ subscapularis
103
What is the rotator cuff interval reinforced by?
- Long head of the biceps
- Coracohumeral ligament
- Superior and middle capsular ligaments
104
The long head of the biceps originates where?
- The supraglenoid tubercle and the labrum
- The intracapsular tendon crosses the humeral head
- Runs through the inter tubercle groove on the anterior humerus
105
What does the long head of the biceps resist?
Anterior translation of the humeral head
106
The glenoid labrum is a _____ ring.
fibrocartilaginous
107
The glenoid labrum gets _____ percent of its depth from its structures and is a stabilizer.
50%
108
What are the 5 tissues that reinforce or deepen the glenohumeral joint?
- Joint capsule/ GH capsular ligaments
- Coracohumeral ligaments
- Rotator cuff muscles (SITS)
- Long head of the biceps
- Glenoid labrum
109
The GH joint is like a ...
Ball on an inclined surface
110
What provides ligamentous support for scapulothroacic posture?
Superior capsular structures: superior capsular ligament, coracohumeral ligament, and the tendon of the supraspinatus
111
When looking at a free body diagram, the force from the humerus into the GH joint labeled CF is what?
The compressive force
112
The coracoacromial arch is formed by what two structures?
- Coracoaromial ligament
- Acromion process
113
What is considered the "roof" of the GH joint?
The coracoacromial arch
114
The coracoacromial arch is _____ cm in adults at rest with their arms by their sides.
1 cm
115
The subacromial space is the space between the _____ and the _____ _____.
Arch; humeral head
116
What is within the subacromial space?
- Supraspinatus muscle
- Supraspinatus tendon
- Subacromial bursa
- Long head of the biceps
- Superior capsule
117
Where are bursa sacs typically placed around the GH joint?
Situated where significant frictional forces develop such as between tendons, capsules and bone, muscles and ligaments, and 2 adjacent muscles
- there are 2 superior to the humeral head
118
The subacromial bursa protects what muscle from what bone?
Protects the supraspinatus from the acromial bone
119
The subdeltoid bursa limits friction forces between what muscle and what bone?
Limits friction between the deltoid and the supraspinatus tendon and the humeral head
120
The shoulder has how many degrees of freedom?
3 degrees (flexion/extension, abduction/adduction, internal/ external rotation)
121
The shoulder also has a 4th motion, what is it?
Horizontal abduction/ adduction that starts at 90 degrees of abduction
122
Horizontal abductions sits on what axis?
Vertical axis
123
What is the anatomical position of the shoulder?
0 degrees
124
Rotation (abduction/adduction) of the humerus is done in what plane and on what axis?
- The frontal plane
- The anterior - posterior axis
125
During shoulder abduction when does the scapula start to upwardly rotate as well?
At 60 degrees
126
What is the arthrokinematic movement of humerus abduction?
The convex head of the humerus rolls superior and slides inferiorly along the longitudinal diameter of the glenoid fossa
* adduction is reverse
127
What tendon blends with the superior capsule?
Supraspinatus
128
Active contractions pull the capsule tight and prevent it from being punched between what two surfaces?
The humeral head and the undersurface of the acromion
129
At 90 degrees of abduction the humeral head stretches out the inferior capsular ligament (axillary pouch) which acts like a hammock and supports what?
The head of the humerus
130
Where will you find the most (7.5 mm) acromiohumeral distance? (chart in words)
When shoulder abduction is at 20 degrees
131
Where will you find the least (2.6 mm) acromiohumeral distance? (chart in words)
When shoulder abduction is at 85 degrees
132
Where will you find the middle amount (5 mm) of acromiohumeral distance? (chart in words)
When shoulder abduction is at 150 degrees
133
At a low degree (about 20-35 degrees) of abduction what is closest to the undersurface of the acromion?
The humeral head
134
At a medium degree (about 35-70 degrees) of abduction what is closest to the undersurface of the acromion?
Distal attachment of the supraspinatus
135
At a high degree (about 70-160 degrees) of abduction what is closest to the undersurface of the acromion?
Proximal shaft of the humerus
136
At what degree is the supraspinatus usually compressed?
35-70 degrees
137
What is adhesive capsulitis?
Excessive thickening or stiffness in the inferior capsular ligament
138
What does adhesive capsulitis limit?
Limits inferior slide of the humeral head
139
The superior roll in adhesive capsulitis leads to what?
- Jamming of the humeral head against the coracoacromial arch
- There is only 22 degrees before this without any slide
140
What is impingement syndrome?
An unnatural and repeated compression or abrasion that may damage the suprasinatus tendon, subacromial bursa, long head of the biceps tendon, or the superior parts of the capsule
141
Over time repeated compression may lead to what?
Impingement syndrome
142
Flexion is rotation of the humerus in what plane and on what axis?
- The sagittal plane
- The medial-lateral axis
143
What are the arthrokinematics of shoulder flexion?
Spinning motion of the humeral head in the fossa
144
During shoulder flexion are most of the surrounding capsular structures taut or slackened?
Taut
145
In extremes of flexion tension in the posterior capsule may cause a slight _____ translation of the humerus.
Anterior
146
How many degrees of GH flexion do we get and then how much do we get when we add the scapula in?
- 120 degrees of GH flexion
- 180 degrees includes the scapula
147
How much active and passive extension do we get at the shoulder?
- 65 degrees of active extension
- 80 degrees of passive extension
148
Extension causes a slight _____ tilt of the scapula and stretch of capsular ligaments
Anterior
149
Axial rotation of the humerus (IR and ER) is done in what plane and along what axis?
- The horizontal plane
- The longitudinal axis
150
In neutral where do we sit when it comes to IR and ER?
- 75-85 degrees of internal rotation
- 60-70 degrees of external rotation
151
What are the arthrokinematics of internal and external rotation?
- Occurs over a transverse diameter
- Roll posterior, slide anterior for external rotation
- Roll anterior and slide posterior for internal rotation
152
At what degree of abduction is external rotation primarily spinning?
90 degrees
153
How many kinematic principles are there for shoulder abduction?
Six - motion is not at a specific joint but at the whole complex
154
The first kinematic principle is scapulohumeral rhythm, what does this mean?
- There is a generalized 2:1 ratio of scapulohumeral rhythm so for every 3 degrees of abduction you get 2 degrees of GH joint and 1 degree of ST upward rotation
- You have active shoulder abduction of about 180 degrees that occurs as a result of simultaneous 120 degrees of GH joint and 60 degrees of scapulothoracic upward rotation
155
The second kinematic principle is SC and AC joint movement during full abduction, what does this mean?
The 60 degrees of upward rotation of the scapula during full shoulder abduction is the result of a simultaneous elevation at the sternoclavicular (SC) joint combined with upward rotation at the acromioclavicular (AC) joint
156
The third kinematic principle is also SC and AC joint movement during full abduction, what does this mean?
- The clavicle retracts at the SC joint during shoulder abduction
- The clavicle is horizontal about 20 degrees posterior to the frontal plane to start
- During abduction the clavicle retracts another 15-20 degrees
- The clavicle does more in the frontal plane than the scapula or flexion
157
What is the fourth kinematic principle?
- The upwardly rotating scapula posteriorly tilts and less consistently externally rotates slightly during full shoulder abduction
- At rest it is anteriorly tilted 10 degrees and internally rotated 30-40 degrees
- With abduction it posteriorly tilts 20 degrees
158
What is the fifth kinematic principle?
- The clavicle posteriorly rotates around its own axis during shoulder abduction
- 20-35 degrees during full abduction
- This is the most predominant motion of the clavicle with abduction
- Those with subacromial impingement showed reduced rotation
159
What is the sixth kinematic motion?
- The GH joint externally rotates during shoulder abduction
- Allows the greater tubercle on the humerus to pass posterior to the acromion
- Strict frontal plane has more than scaption
- 25-50 degree range; majority occurring before 70-80 degrees of abduction
