Shoulder Complex Flashcards
How many muscles attach to the scapula?
17
During R shoulder flexion, what movements occur in the upper thoracic vertebrae?
- extension
- R rotation
- R sidebending
During R shoulder flexion, what movement occurs in ribs 1 and 2?
depression
During R shoulder flexion, what movement occurs in ribs 4-6?
elevation
The humeral head is ___x larger than the glenoid fossa
3-4x
The humeral head faces:
medial
posterior
superior
Humeral head: angle of inclination
130˚
Humeral retroversion:
30˚
Strength ratios of IR to ER in the shoulder
3 to 2
Women have (%) shoulder strength as men
40-65%
Only (%) of all new episodes of shoulder pain presenting in primary care show recovery by 6 months
50%
SC joint: degree of mobility
elevation and depression
30˚-40˚
SC joint: degree of mobility
rotation
40˚-50˚ (with ACJ)
SC joint: degree of mobility
Protraction/retraction:
~30˚
This joint is the only true skeletal articulation between the axial skeleton and appendicular upper limb
SC joint
SCJ shape, number of articulations
saddle shaped
diarthrodial jt
ACJ relies on this for support
ligamentous stability
- superior/inferior AC ligaments
- coracoclavicular ligaments (conoid/trapezoid)
ACJ mobility:
elevation and depression
30˚
ACJ mobility:
rotation
40˚-50˚ (with SCJ)
ACJ moves in 3 planes: what are they?
- elevation/depression
- rotation
- protraction/retraction
Scapulothoracic joint is this type
physiological articulation - no bone on bone connection
Scapulothoracic joint: degree of upward rotation
60˚
Scapulothoracic joint: degree of posterior tilt
15-30˚
Scapulothoracic joint: degree of ER
15-25˚
Scapulohumeral rhythm:
ratio of GHJ to STJ motion
2:1
120˚ from GHJ, 60˚ from scapula
Scapulohumeral rhythm:
Which muscles initiate abduction?
deltoid
supraspinatus
Scapulohumeral rhythm:
This muscle sucks the scapula against the thorax
serratus
Scapulohumeral rhythm:
Pure GH motion in this range
0-45˚
Scapulohumeral rhythm:
From 45-60˚, what occurs?
- humerus slides inferiorly
- scapula begins to move
Scapulohumeral rhythm:
This occurs at approximately 75˚
humeral ER
Scapulohumeral rhythm:
At 110˚ this occurs
CC ligament tightens
Passive stabilizers of the shoulder
- bony shape
- glenoid labrum
- limited joint volume
- intra-articular pressure
- capsuloligamentous structures
GHJ Capsule: This alone provides little support without
other dynamic and static stabilization
GHJ Capsule: Capsular strength has this relationship to age
inverse:
older pt = weaker capsular tissue
GHJ Capsule: Capsular pattern
ER > ABD > IR
GHJ supporting structures: What are the static stabilizers of the joint?
- superior GH ligament
- middle GH ligament
- inferior GH ligament
- coracohumeral ligament
GHJ supporting structures:
Superior GH ligament provides
inferior restraint with arm abducted
GHJ supporting structures:
middle GH ligament provides restraint to
- anterior translation
- ER
GHJ supporting structures:
Inferior GH ligament composed of these bands
anterior
posterior
Actions of levator scapulae
adduction
downward rotation
elevation
rhomboids actions
- adduction
- downward rotation
Rhomboids originate where?
nuchal ligament and SPs of C7-T5
Rhomboids insert where?
medial scapular border
Upper Trapezius actions
- upward rotation
- elevation
Serratus anterior actions
- holds scapula against ribcage
- upward rotation
- posterior tilt
Serratus anterior couples with this muscle for elevation
trapezius
Patients with impingement have shown:
decreased levels of ___ activity
serratus anterior
Patients with impingement have shown:
delay in firing of these muscles
middle/lower trapezius
Patients with impingement have shown:
dominance of these muscles resulting in a faulty scapuloumeral rhythm pattern
- UT
- LT
RTC muscles
- supraspinatus
- infraspinatus
- subscapularis
- teres minor
If the long head of the biceps is torn, will have decreased ability with these movements
- elbow flexion
- supination
- shoulder abduction
Long head of the biceps has a significant role in ____ shoulder stability
anterior
