Anatomy of Shoulder Flashcards
(92 cards)
0
Q
Sternoclavicular Joint
- classification
- articular surfaces (2)
- ligaments and fibrous capsule (4 ligaments)
- movements (df, types)
- resting position
- closed packed position
- capsular pattern
A
- classification: complex joint (disk)
- -mechanically bi-axial saddle joint
- -anatomically ball-and-socket joint (lax capsule and flexible disk) - articular surfaces
- -clavicle (sternal end): convex vertically and slightly concave anterior-posteriorly
- -sternum: clavicular notch/facet of manubrium: concave vertically and convex anterior-posteriorly - ligaments and fibrous capsule: disk, SCM reinforces it
- -anterior sternoclavicular ligaments
- -posterior sternoclavicular ligaments
- -interclavicular ligaments:
- -costoclavicular ligament - movements: 3 degrees of freedom [elevation with retraction, depression with protraction]
- resting position: arm at side
- closed packed position: arm abducted to 90 degrees
- capsular pattern: pain with extrenes of motion
1
Q
Shoulder Complex/girdle Joints
8
A
- Sternoclavicular (SC)
- Acromioclavicular (AC)
- Scapulothoracic (ST)
- Glenohumeral (GH)
- Suprahumeral
- Costosternal
- Costovertebral
- Bicipital Groove
2
Q
SC Joint Classification
A
classification: complex joint (disk)
- -mechanically bi-axial saddle joint
- -anatomically ball-and-socket joint (lax capsule and flexible disk)
3
Q
SC Joint Articular Surfaces
A
articular surfaces
- -clavicle (sternal end): convex vertically and slightly concave anterior-posteriorly
- -sternum: clavicular notch/facet of manubrium: concave vertically and convex anterior-posteriorly
4
Q
SC joint: ligaments and fibrous capsule
4
A
ligaments and fibrous capsule: disk, SCM reinforces it
- -anterior sternoclavicular ligaments
- -posterior sternoclavicular ligaments
- -interclavicular ligaments:
- -costoclavicular ligament (clavicle to 1st rib, important)
5
Q
SC joint Movement
- -DF
- -caudal and cranial
- -dorsal and ventral
- -rotation
A
movements: 3 degrees of freedom [elevation with retraction, depression with protraction
movement of the clavicle
- clavicle moves with its convex surface for caudal and cranial directions about a sagittal axis
- —elevation 45-60 degrees
- —depression 5 degrees
- clavicle and disk move with concave surface for ventral and dorsal directions about a vertical axis
- —protraction 15 degrees
- —retraction 15 degrees
rotation of clavicle about its own longitudinal axis: 30-50 degrees (to elevate the arm)
6
Q
SC resting position
A
resting position: arm at side
7
Q
SC closed packed position
A
closed packed position: arm abducted to 90 degrees
8
Q
SC Capsular Pattern
A
capsular pattern: pain with extrenes of motion
9
Q
SC joint Disk
A
disk subdivides joint into 2 secondary cavities
- -attachment above to the upper and posterior borders of articular surface of clavicle
- -below to the cartilage of the 1st rib near its junction with the sternum and circumferentially to the fibrous capsule
10
Q
what muscle helps to reinforce the SC joint?
A
SCM
11
Q
Anterior sternoclavicular ligaments
A
above to upper and front part of sternal end of clavicle, passes obliquely downwards and medially
below to the front of upper part of manubrium sterni and more laterally to the first costal cartilage
12
Q
posterior sternoclavicular ligament
A
attached posterior aspect of sternal end of clavicle
passes obliquely downwards and medially to back of the upper part of the manubrium sterni
13
Q
interclavicular ligament
A
unites upper part of the sternal ends of both clavicles with some fibers attached to the upper margin of the manubrium
14
Q
costoclavicular ligament
A
consists of anterior and posterior laminae attached below to the upper surface of the 1st rib and the adjacent part of its cartilage and above to the margins of the impression on the inferior surface off the medial end of the clavicle;
fibers of anterior laminae directed upward and laterally
fibers of posterior lamina directed upwards and medially
bursa between the two laminas
15
Q
degrees of freedom at SC joint
A
3 degrees of freedom functionally
–usually: elevation with retraction; depression with protraction
16
Q
Degrees of Movement at SC Joint: Clavicle
A
Caudal and Cranial Direction: clavicle moves with its convex surface about sagittal axis; elevation 45-60 degrees; depression 5 degrees
Ventral and Dorsal Direction: clavicle moves with concave surface about vertical axis; protraction 15 degrees; retraction 15 degrees
rotation: rotation of clavicle around its own longitudinal axis: 30-50 degrees
17
Q
AC Joint
- classification
- articular surfaces
- ligaments and fibrous capsule
- movements
- resting position
- closed packed position
- capsular pattern
A
- AC joint classification: anatomically simple joint, mechanically compound plane gliding joint, functionally a ball and socket joint (because of lax capsule and disk when present)
- articular surfaces: acromion, clavicle, articular disk
- fibrous capsule surrounds the articular margins, a. acromioclavicular ligament, b. coracoclavicular ligament
- movements: abduction/adduction (sagittal axis), winging (vertical axis), tilting of inferior angle away from chest wall as in protraction (long axis through clavicle)
- resting position: arm at side
- closed packed position: upwards rotation of scapula with arm abduction-narrows thoracic inlet as does horizontal adduciton of the arm
- capsular pattern: pain with elevating arm or with horizontal adduction, limited full extension
18
Q
AC joint classification
A
anatomically simple joint
mechanically compound plane gliding joint
functionally ball and socket joint because of lax capsule and disk
19
Q
AC Joint Articular Surfaces
A
antero-medial border of acromion: flat and slightly convex (authors disagree), facing anteriorly/medially/and superiorly
inferior aspect of clavicle: flat and slightly convex facing inferiorly, posteriorly and laterally
articular disc (1/3 of population): occupies upper part of articulation and only partially separates the articular surfaces, rarely divides the joint completely
20
Q
Acromioclavicular ligament
A
of SC joint
covers superior part of joint, extends between upper part of acromial end of clavicle and adjoining part of upper surface of acromion
21
Q
AC Joint Biomechanics
ASK
A
Sagittal Axis: abduction/adduction (upward/downward rotation) of lower end of scapula around the chest wall = 20-30 degrees
Vertical Axis: winging scapula: vertebral border of scapula moves away from the chest wall = 30-50 degrees
Long Axis through clavicle: tilting of inferior angle away from the chest wall as in protraction = 30 degrees
22
Q
coracoclavicular ligament
A
Primary supported of the AC joint (acromioclavicular joint)
2 parts separated by fat or bursa
trapezoid: attached below to upper surface of coracoid process and above to trapezoid line on inferior surface of clavicle
conoid: (triangle shape): attached at its apex to medial and posterior edge of root of coracoid process just in front of scapular notch; base is attached to conoid tubercle on inferior surface of clavicle and to a short length of clavicle medial to conoid tubercle
23
Q
Scapulothoracic Movements (3)
A
Elevation and Depression
Retraction and Protraction
Downward and Upward Rotation
24
AC Joint Resting Position
arm at side
25
AC Joint Closed Packed Position
upward rotation of the scapula with arm abduction narrows the thoracic inlet, as does horizontal adduction of the arm
26
AC Capsular Pattern
pain with elevating arm or with horizontal adduction, limited full extension
27
Scapulothoracic joint vs articulation
not a true joint/ ST articulation riding of scapula on posterior thoracic wall
ST doesnt have a capsular pattern or a closed packed position, but its resting position is arm at side
28
Ligaments of ST Joint
coracoacromial ligament: apex attached to the edge of the acromion, just in front of the articular surface for the clavicle and base is the whole length of the lateral border of the coracoid process
superior transverse (scapular) ligament: converts the scapula notch into a foramen and sometimes is ossified, attached to base of coracoid process and medial end of scapular notch [if ossify can get nerve conduction issue-rotator cuff issues bc suprascapular nerve]
29
coracoacromial ligament
arch over humeral head, block superior translation
apex attached to the edge of the acromion, just in front of the articular surface for the clavicle
and base is the whole length of the lateral border of the coracoid process
29
transverse humeral ligament
forms roof over bicipital groove to hold long head of biceps tendon into the groove
31
superior transverse scapular ligament
converts scapular notch into a foramen and is sometimes ossified
attach to base of coracoid process and medial end of scapular notch
This notch is converted into a foramen by the superior transverse scapular ligament, and serves for the passage of the suprascapular nerve, sometimes the ligament is ossified. (can cause issue)
32
GH Joint
1. classification
2. articular surfaces
3. ligaments
4. biomechanics
5. resting position
6. closed packed position
7. capsular pattern
1. classification: anatomically and mechanically: simple ball and socket joint (multiaxial, synovial, ball and socket joint)
2. articular surfaces: head of humerus, glenoid cavity (glenoid labrum),
3. ligaments: capsule, superior band, middle band, inferior band, coracohumeral ligament, transverse humeral ligament
4. movements: 3 degrees of freedom
- -flexion/extension
- -abduction/adduction
- -external rotation/internal rotation
5. resting position: position of maximal laxity: 55 degrees abduction, 30 degrees horizontal adduction
6. closed packed position: full abduction and external rotation
7. capsular pattern: external rotation > abduction > internal rotation
33
GH Joint Type
anatomically and mechanically a simple ball and socket joint
34
GH Joint Articular Surfaces
head of humerus--covered with hyaline cartilage faces superiorly, medially, and posteriorly convex ovoid surface that approximates a spherical shape much larger than glenoid cavity
```
glenoid cavity (glenoid labrum)
glenoid cavity of scapula: hyaline cartilage faces laterally, anteriorly, slightly superiorly, biconcave transversely and vertically but irregular.
```
glenoid
glenoid labrum fibrocartilagenous _ attach to margin _ glenoid cavity to slightly widen and appreciably deepen cavity
glenoid is 1/2 as long and 1/3 as wide as head of humerus. lit more than 1/3 of the humerus contacts cavity at any one time. stability achieved through muscles, tendons, and capsule.
read netter on ball and plate joint vs ball and socket joint
35
head of the humerus
- what direction it faces
- shape of surface
- faces superiorly, medially, and posteriorly
- convex ovoid surface
- when relaxed the humerus sits centered in the glenoid cavity, when contracted of rotator cuff muscles it translates anteriorly, posteriorly, inferiorly, superiorly based on the movement.
36
glenoid cavity of scapula
- which way does it face?
- concave or convex?
hyaline cartilage faces laterally, anteriorly and slightly superiorly
biconcave transversly and vertically but irregular
40
Glenoid Labrum
- -what is it
- -its significance
1-ring of fibrocartilage that surrounds (slightly widens) and deepens the glenoid cavity of the scapula about 50%
2-only part of the humeral head is in contact with the glenoid at any given time
41
capsular pattern at the GH joint
external rotation most limited > abduction > internal rotation
42
how does the size of the glenoid fossa compare to the head of the humerus?
how much is in contact?
what provides stability?
the glenoid fossa is 1/2 as long and 1/3 as wide as the head of the humerus
1/3 of the head of the humerus contacts the cavity at any one time
stability is achieved through muscles, tendons, and capsule
43
GH joint capsule
- type, amount of motion
- attach: medial, superior, lateral, inferior
- what is least supported
- fibrous capsule with laxity--allows motion
- attached medially to circumference of glenoid cavity and beyond labrum
- above to coracoid process (includes long head bicep in joint)
- laterally to anatomical neck of humerus (close to articular margin except medial side where it descends to shaft of humerus)
- inferior least supported and subject to GREATEST STRAIN, it has redundant fold, axillary recess
44
what ligaments support GH capsule: superior, inferior, anterior, posterior
Superior: supraspinatus
inferior: long head of triceps
anterior: subscapularis tendon
posterior: infraspinatus and teres minor
tendons of rotator cuff muscles blend with fibrous capsule for reinforcement and active support
45
middle glenohumeral ligament
limit external rotation
46
inferior glenohumeral ligament
most important, has an anterior and posterior band with a thin pouch in between so it acts like a hammock or sling
supports the humeral head above 90 degrees of abduction: limits inferior translation
anterior band tightens on internal rotation
(anterior can get stretched with too much external rotation)
47
coracohumeral ligament
coracoid process to greater tubercle of humerus
blends with supraspinatus tendon (unites it to the superior border of the subscapularis tendon
limit inferior translation and help limit external rotation (below 60 degrees of abduction)
48
superior glenohumeral ligament
limit inferior translation and adduction
| it also restrains anterior translation and lateral rotation up to 45 degrees of abduciton
49
Primary Ligaments of the GH joint:
superior, inferior and middle glenohumeral ligaments stabilize the shoulder
1. superior glenohumeral ligament:
50
GH Capsule
- laxity/motion
- attached: medial, superior, lateral, inferior
fibrous capsule, laxity, high degree motion
medial: glenoid cavity circumference/labrum
superior: coracoid process (include longhead biceps)
lateral: humerus (anatomical neck-close to articular margin except for at the medial side descend to shaft of humerus)
inferior: LEAST supported and this subject to greatest strain, has redundant fold, axillary recess
* ****pain if bicep tendinitis or adhesive capsulitis under redundant fold
51
```
What reinforces the GH capsule
anterior
posterior
superior
inferior
```
anterior: subscapularis tendon
posterior: infraspinatus, teres minor
superior: supraspinatus
inferior: long head of triceps
tendons of rotator cuff muscles blend with capsule for reinforcement and support
52
glenohumeral ligament: superior band
- where is it
- when is it taut
pass along medial edge of biceps tendon and attach above lesser tubercle
taut in inferior translation and adduction
53
glenohumeral ligmament medial band
to lower part of lesser tubercle
limit ER
54
glenohumeral ligament inferior band
to lower part of anatomical neck of humerus
limits inferior translation
anterior band of it is tait on IR
55
glenohumeral ligaments
attached at scapular end to upper part of medial margin of glenoid cavity and are blended with labrum
superior band
middle band
inferior band
56
GH joint, degrees of freedom
```
3:
flexion (120)
extension (55)
abduction (120)
adduction (neutral)
internal rotation (60-70)
external rotation (90)
```
57
GH flexion degrees
120
58
GH extension degrees
55
59
GH Internal Rotation Degrees
60-70
60
GH External Rotation
90 degrees
61
GH Abduction Degrees
120
62
GH Adduction Degrees
Return to Normal
63
GH Joint Capsular Pattern
external rotation > abduction > internal rotation
64
GH Resting Position
Position of maximum laxity (assessment and joint mobilization)
55 degrees ABDUCTION
30 degrees HORIZONTAL ADDUCTION
65
GH Closed Packed Position
maximum abduction and external rotation
66
is suprahumeral joint a real joint?
NO
humerocoracoacromial joint: coracoacromial arch: acromion and coracoacromial ligament
67
costosternal joint
-why we watch it
sternal and spinal joint substitutions
68
what joint is innervated by the subscapular and lateral pectoral nerve?
AC Joint
69
what joint is innervated by the anterior supraclavicular nerve and the nerve to the subclavius muscle?
the SC joint
70
Bursa Shoulder Region (8)
1. between subscapularis and joint capsule*
2. between infraspinatus and capsule
3. summit of acromion
4. between coracoid and capsule
5. behind coracobrachialis
6. between teres major and longer head of triceps
7. anterior to and posterior to tendon of latissiumus dorsi (2)
8. subdeltoid (subacromial)*
* Palpate course of muscle, when you get point of attachment, see if that is causing cardinal pain of the patient – differentiate from cuff tear
* subacromial, subdeltoid bursa – most problematic if doing abduction without ER arm
71
3 Groups of Muscles at the Shoulder Region
scapulothoracic--axioscapular
thoracohumeral--axiohumeral
scapulohumeral--scaoulohumeral
72
Scapulothoracic (axialthoracic)
* elevation depression of scapula upward and downward rotation of scapula ab/adduction
* pectoralis minor, serratus anterior, rhomboids levator scapulae
73
Thoracohumeral (axiohumeral)
* latissimus dorsi – extension and internal rotation of humerus
* pectoralis major – horizontal adduction of humerus, internal rotation, flexion (clavicular head)
74
Scapulohumeral (scapulohumeral)
* flexion/extension of humerus
* abduction/adduction
* internal/external rotation
* subscapularis, teres major, teres minor, supraspinatus, infraspinatus, coracobrachialis, deltoid
75
Nervous Tissue: Shoulder Region
• Brachial plexus – capsule C5 structure, can have referred pain out into deltoid
o Palpate to find source of problem
o Comes underneath clavicle – be careful during palpation
• Dermatome: Sensory: C4,C5, C6, C7
• Myotome: Motor
76
Vascular Structures Shoulder Region
Vascular structures support the tissues
o posterior humeral circumflex artery ad suprascapular arteries
o anterior humeral circumflex artery
o thoraco-acromial artery (sometimes absent)
o suprahumeral and subscapular arteries (often absent)
77
Biomechanics of the shoulder
- degrees of freedom
- motions
1. TRANSVERSE AXIS: flexion-extension
2. ANTEROPOSTERIOR AXIS: abduction-adduction
3. VERTICAL AXIS: horizontal abduction/horizontal adduction
4. LONGITUDINAL AXIS: external rotation/internal rotation (due to movement at the other 3 axes)
78
What three true joints and three virtual joints make up the shoulder complex?
SC, AC, GH,
scapulothoracic, subdeltoid/coracoacromial arch/suprahumeral, substernal
costovertebral
bicipital groove is not a true jt
79
what do we have to be careful about in palpating the clavicle?
brachial plexus comes under it
80
Articulations of the shoulder complex
three true joints
three virtual joints
two not real joints
• Articulations – shoulder complex is made up of three true joints and three virtual joints
o sternoclavicular
o acromioclavicular
o glenohumeral
o scapulothoracic
o subdeltoid/coracoacromial arch/suprahumeral
o substernal
'o NOT TRUE JOINTS: costovertebral, biciptal groove
81
What can cause pain/referred pain to the shoulder region?
compressive or tensile forces on neurovascualar structures
referred pain to shoulder region: cervical spine, thoracic spine, viscera, myocardium
82
True Shoulder related joints
SC
AC
GH
83
Not true joints shoulder
```
ST
subdeltoid space
coracoachromial arch
substernal
bicipital groove
```
84
SC: elevation, depression, protraction, retraction (3 axis of movement, not true x, y, z
the 3 movement axes
a. Elevation will be more than depression
b. Movements on a disc at the SC joint
c. Saddle joint:
AP axis : Elevation and depression: convex on concave:
Vertical axis: Protraction retraction: concave on convex
Longitudinal axis: Rotation: clavicle
85
AC joint:
scapular motions
a. Clavicle on acromion or visa versa
Saggital plane, upward and downward rotation along that A-P axis
Winging: Pulling away from spine and rib cage or going towards---Vertical axis, horizontal plane adjustments
Tipping: bring inferior angle of scapula backwards or forwards---Pivot on a Medial to lateral type of axis
86
. Scapulathoracic joint (not true joint) (we can look at these as translations at this joint)
what motions (2)
a. Elevation, depression
| b. Abduction, adduction towards and away from the spine
87
SC and AC joint working together:
explain protraction and retraction
what does clavicle do to the scapula at SC and at AC
Protraction and retraction: Newman picture: clavicle on sternum at SC: the protraction of clavicle will drag along the scapula, the pivot point at the SC joint
Thorax bumps out as do protraction and retraction—winging (bumping out) helps scapula bump out around rib cage—bumping out from the AC joint
88
Upward rotation at scapula: how much SC how much AC?
what about GH?
Upward rotation: 50% SC (30 degrees), 50% AC (30 degrees)
i. Pivot point at the AC joint upward rotation
ii. Clavicular elevation at SC joint
iii. ST elevation and upward rotation
iv. GH 2:1 ratio
89
GH joint motions
vertical axis
AP axis
transverse axis
long bone axis
vertical axis: Horizontal Adduction/abduction
A-P Axis: abduction, aduction
Transverse axis: flexion, extension
Long bone is the axis: internal rotation, external rotation
90
GH Joint Motion--what are the osteokinematics
```
Flexion
Extension
Abduction
Adduction
IR
ER
```
flexion--Anterior
extension---Posterior
abduction---Superior
IR---Anterior
ER---Posterior
91
GH Joint Motion--what are the Arthrokinematics
```
Flexion
Extension
Abduction
Adduction
IR
ER
```
flexion--Posterior glide
extension---Anterior glide
abduction---Inferior glide
IR---Posterior glide
ER---Anterior glide
92
```
SC joint Motion
Elevation
Depression
Protraction
Retraction
```
SC joint Motion--- Osteokinematics--- Arthrokinematics
1. Elevation ---Superior--- Inferior glide
2. Depression ---Inferior --- Superior glide
3. Protraction ---Anterior--- Anterior glide
4. Retraction ---Posterior--- Posterior glide
93
AC separation—AC ligament would go first if fall or have a trauma to that area due to a loose capsule with some give, it is the furthest from axis
3 grades
I. Grade 1 AC separation: may be too small to see on xray—probably stretch the AC ligament and may have a partial tear
II. Grade 2 AC separation: some more separation and completely tear the AC ligament, may not be seen at rest on xray. Increased laxity on mobility test
III. Grade 3 AC separation: rupture AC ligament and still have trauma and energy that will need to dissipate and may tear some or all of the coracoclavicular ligament and clavicle will be popping up, and have an anatomical abnormality.
94
X axis = transverse axis
Y axis = vertical axis
Z axis = anteroposterior axis
X axis = transverse axis
Y axis = vertical axis
Z axis = anteroposterior axis
