final- Shoulder Flashcards
What 4 joints contribute to the shoulder complex?
What are other contributors?
Glenohumoral
Acromioclavicular
Sternoclavicular
Scapulocostal
- costosternal
- costochonral
- costotransverse
- costovertebral
- suprahumeral
- Cox, Tex, Lx intervertebral
What is the most complex joint in the body?
Glenohumoral
Which joint has the greatest freedom range
Glenohumoral (ball and socket)
What are the 7 major movements of the glenohumoral joint?
- Flexion
- Extension
- Adduction
- Abduction
- Internal Rotation
- External Rotation
- Circumduction
What makes the glenoid fossa less stable? 3
- shallow
- much smaller than the humeral head
- anteverted (tilted slightly anterior)
What is the lip of the glenoid labrum composed of? What % of depth does it account for?
Fibrocartilage
50%
The tendon of the long head of the biceps attaches to which part of the glenoid labrum? What also attaches there?
- Superior part
- rotator cuff
What is a SLAP lesion?
- superior labrum anterior-posterior lesion
- often due to repetitive use
What is Bankart lesion?
- anterior-inferior detachment
- Often due to dislocation
Which is more common, SLAP or Bankart?
SLAP
What are the 4 common causes of labral damage?
- repetitive overuse (SLAP)
- hypermobility
- instability
- dislocation (Bankart)
The humeral head faces _________ and _______. It is retroverted __degrees?
Medially and superiorly
30 degrees
Is the joint capsule (strong/weak) for the following:
- anteriorly
- inferiorly
- posteriorly
- strong
- strong
- weak
What are the 4 major ligaments of the anterior capsule? What is their function
- coracohumeral
- superior GH
- middle GH
- inferior GH
- maintain a (-) intra-articular pressure and help resist external rotation and extension (throwing/reaching back) (i.e. anterior translation of the shoulder)
Which anterior capsule ligament is the most important with arm abducted >90 degrees?
Inferior GH
What does the coracoid-humeral ligament resist?
Distraction and inferior translation
What does the superior GH ligament resist?
Main restraint to discretion and external rotation
What does the middle GH ligament resist?
Distraction and external rotation
- especially with arm abducted 45-60 degrees
What does the inferior GH ligament resist?
- resists Inferior glide and P-A translation
* Most important ligament with arm abducted >90 degrees
What do the axillary folds resist?
Increased laxity = (increased/decreased) dislocations
Decreased laxity = (increased/decreased) TOM
-extremes of internal and external rotation
- increased dislocation
- decreased ROM (adhesive capsulitis)
What are the primary stabilizers? 3
- coracoid-humeral ligament
- superior GH ligament
- tendon of the supraspinatus
All three result in a compressive locking force into the glenoid fossa
What are the secondary stabilizers?
Rotator cuff
What are the most vulnerable positions to dislocation?
- abduction and external rotation with a P-A force
OR
- falling on outstretched hand (FOOSH) injury
Most dislocations are (anterior/posterior)
Anterior
What are the 4 rotator cuff muscles?
- supraspinatus
- infraspinatus
- teres minor
- subscapularis
What are the two regions of the capsule not covered by the cuff?
- inferior portion
- rotator interval
Which tendons is the rotator interval between?
supraspinatus and subscapularis
*common site for anterior dislocation
Where is the site of impingement? It includes (superior/inferior) role and (superior/inferior) slide?
Subacromial space (Supra,biceps, bursa) at 80-120 degrees
- superior roll
- inferior slide
What increases impingement?
- IR and adduction (especially above 90)
- superior translation
- hypertonic deltoids, internal rotators and abductors
- increased Thx kyphosis
- anterior head carriage
- shoulder hiking
What factors decrease impingement?
- ER
- inferior translation
- increased rotator cuff (especially external rotators)
The AC joint starts as a _________, then becomes a meniscus by age 20 and appears degenerated by age 20-30
Fibrocartilagenous symphysis
What is the most important AC joint ligament?
Coracoclavicular (conoid, trapezoid)
T/F the AC joint resists distraction?
T
What causes distraction at the AC joint?
- abduction
- flexion
- ER
- lifting (i.e. suitcase)
- pull-up or chin-up
What causes Compression at the AC joint?
- horizontal adduction
- pushing
- pulling (@ 90 degrees)
Which joint is smaller and more prone to dislocation, the AC or SC?
AC
What type cartilage is the SC?
Fibrocartilagenous
Which joint links the appendicular skeleton to the axial skeleton?
SC
*firmly attached but considerable ROM
The anterior fibers of the costoclavicular ligament of SC joint resists? 4
- *distraction
- elevation
- *external rotation
- depression
The posterior fibers of the costoclavicular ligament of SC joint resists? 4
- *compression
- elevation
- *internal rotation
- depression
At what degrees do the three phases of scapulohumeral rhythm occur?
Phase 1 = 0-30
Phase 2 = 30-90
Phase 3 = 90-180
The humerus at the GH it accounts for ___ degrees
120
The scapula accounts for __ degrees
60
The clavicle at the SC joint accounts for __ degrees
25 elevation and 25 posterior rotation
The acromian at the AC joint accounts for ___ degrees of upward rotation of the distal clavicle
35
The total motion of the shoulder is ____ degrees. The GH joint accounts for / and / involves the shoulder girdle
180
2/3
1/3
In phase 1 of scapulohumeral rhythm, the GH:Scapula ratio is : and has ____ roll and ____ slide
7:1
Superior roll, inferior slide
What muscles initiate abduction in phase 1
Glenohumoral (supraspinatus and deltoid) & Girdle (serratus anterior and traps)
T/F you want a lot of help from upper traps in phase 1
F - don’t want too much upper trap activity. Premature, excessive or uneven hiking can lead to impingement
In phase 1, the SC oint in responsible for (3 things) and the AC joint is responsible for (1 thing)
- begins distal elevation, superior roll, inferior slide
- begins initial rotation
T/F the price movers of the GH joint are the same for phase 1 and phase 2
T
Biceps also helps to abduct and depress humerus and the rotator cuff depresses/counteracts deltoid muscles
Maximum impingement in phase 2 occurs at ____ degrees
80-120
The scapula moves and additional ___ degrees in phase 2
20-25
T/F the upper traps are more involved in phase 2 than phase 1
T - still, too much elevation is bad causing impingement
In phase 2, the SC joint accounts for (2 things) and the AC joint (1 things)
- additional elevation, same superior roll and inferior slide
- additional external rotation
Lack of SC motion may lead to what?
Increased motion and wear and tear on the AC joint
In phase 3, the GH joint has an additional ___ degrees of motion. ___ total
60
120
T/F the GH joint has the same kinematic and prime movers in phase 3 as the other phases
T
In phase 3, impingement is still a problem at _____ degrees and again at 180
80-120
In phase 3, the posterior capsule is reinforced by what muscle?
Triceps long head
*if the triceps is to tight it causes abnormal movement
In phase 3, the scapula experiences and additional ____ degrees of movement. ___ total
30
60
T/F the scapula has different kinematic and muscles acting on it in phase 3 as compared to previous phases?
F - same
T/F upper traps is more active in phase 3
T
What is the different kinematic of the SC joint in phase 3?
More external rotation instead of roll/slide at GH abduction end range
In phase 3, what is the most important stabilizer of the scapula?
Serratus anterior
How does the pec minor stabilize the scap/
Draws it inferior and anteriorly
What are tight adductors that can limit abduction of the shoulder?
GH (last, teres Major, pec major, subscapularis)
Girdle (rhomboids, traps, pec minor)
What are the tight internal rotators the limit abduction of the shoulder?
GH (lasts, pec major, teres major, subscapularis)
Girdle (last, pec minor, rhomboids)
