Shoulder Anatomy Flashcards
The scapula lies in a plane ___ to the back and ___ to the clavicle
30, 60
What type of acromion morphology is a good prognostic indicator for conservative management?
Type 1 Flat
What type of acromion morphology increases the likelihood of impingement on subscapular lig, bursa?
Type 2: curved
What type of acromion morphology is a negative prognostic indicator for conservative management and the greatest correlation with subacromial impingement syndrome?
Type 3: Hooked
The subacromial bursa deep to this ligament allows movement of deeper supraspinatus tendon?
Coracoacromial Ligament
This ligament completes scapular notch to make foramen?
superior transverse scapular ligament
This ligament a arches over suprascapular nerve (entering infraspinous fossa)?
inferior transverse scapular ligament
What the the ring of fibrocartilage attached to the margin of the glenoid cavity that deepens the cavity for increased congruence?
glenoid labrum
What is the angle of inclination of the humeral head?
135
What is the retroversion of the humeral head?
30
The gh joint stabilizer that travels from coracoid process to greater tuberosity?
coraco-humeral ligament
The 3 bands of the GH ligament (superior, middle, and inferior) are ____ in ER and ___ in IR
i. Taut in ER
ii. Slackened in IR
When shoulder positioned in 90 deg abduction, describe effect on middle and inferior fibers of GH ligament.
- Tightening of the middle and inferior fibers of the GH ligament
When shoulder positioned in 90 deg abduction, describe what the inferior GH ligament will resist.
- Inferior GH ligament resists anterior and posterior humeral head translation
T/F The Scaoulothoracic Joint is a false joint between the scapula and thoracic wall
True
What are the 4 stabilizers of the SC joint?
anterior SC ligament, Posterior SC ligament, interclavicular ligament, costoclavicular ligament
Describe arthrokinematics of the sc joint in the vertical plane.
Convex clavicle moving on concave sternocostal
Describe arthrokinematics of the sc joint in the horizontal plane.
concave clavicle moving on convex sternocostal
Why is the AC joint subject to dislocation?
i. Absence of interlocking articular surfaces
ii. Weakness of ligaments
What are the 2 extra-articular ligaments supporting the AC joint?
i. Conoid ligament
ii. Trapezoid ligament
What is the open pack position of the GH joint?
55 abd
30 hor add
slight ER
What are the boundaries of the quadrilateral space?
i. Teres major
ii. Teres minor
iii. Long head of triceps
iv. Surgical neck of humerus
What are the contents of the quadrilateral space?
i. The axillary nerve
ii. Posterior circumflex humeral artery
What three motions will close the quadrilateral space?
Extension, abduction, ER closes space
The rotator cuff interval lies between what tendons?
lies between the supraspinatus and subscapularis tendons
The rotator cuff interval is reinforced by what ligaments?
Reinforced by superior glenohumeral and coracohumeral ligaments
Adhesions in The rotator cuff interval causes the humeral head to sit in which direction?
Anteriorly
The biceps pulley is a Tendoligamentous sling formed by what 3 aspects?
i. Superior glenohumeral ligament
ii. Coracohumeral ligament
iii. Distal attachment of the subscapularis tendon
What stabilizes the long head of the biceps in the bicipital groove (tearing can lead to instability)?
The biceps pulley
Because the GH has (1) a great degree of movement, (2) has little bony congruency, and (3) has poor elasticity of capsule, what provides rapid stability in response to external perturbation?
Rotator cuff
What 3 muscles upwardly rotates the scapula?
Upper Trap, Lower Trap, Serratus Anterior
What muscles posteriorly tips the scapula?
serratus anterior
When the shoulder abd, the contralateral thoracic spine will move into what position during phase 3 of abduction (120-180)
lateral flexion
Phase 1 of shoulder of abd (0-60 deg) uses these muscles mostly?
Deltoid & supraspinatus
Because of the Locking” at 90 deg from greater tuberosity impacting superior margin of glenoid, what motions occur?
lateral rotation and flexion of the humerus to delay lock
Phase 2 of shoulder abduction (60-120) uses these muscles mostly?
Trapezius (upper – upward rotation, lower - posterior tilting) and serratus anterior
What muscles will check phase 2 (60-120) of shoulder abduction?
Checked by latissimus dorsi and inferior pec major
Phase 3 of shoulder abduction (120-180) uses these muscles mostly?
Deltoid, supraspinatus, inferior trapezius, serratus anterior elevate UE
Phase 1 of shoulder flexion (0-50) uses what muscles?
Anterior deltoid, coracobrachialis, and superior clavicular fibers of the pec major initiate shoulder flexion
Phase 1 of shoulder flexion (0-50) is checked by what tension from what muscles?
teres major and minor, infraspinatus, and coracohumeral ligament
Phase 2 of shoulder flexion (60-120) uses what muscles?
Trapezius and serratus anterior
Phase 2 of shoulder flexion (60-120) is checked by what tension from what muscles?
latissimus dorsi and inferior pec major
During phase 2 of shoulder flexion (60-120), the scapular rotates to 60 to do what?
orient glenoid superior & anterior
Phase 3 of shoulder flexion (120-180) uses what muscles?
Deltoid, supraspinatus, inferior trapezius, serratus anterior elevate UE
Check for what nerve with proximal humeral fractures?
Axillary nerve
