Final Learning Objectives Flashcards
Shoulder Girdle
- AC joint → gliding joint
- SC joint → saddle joint
- Scapulothoracic interface → not classified as a joint, but the movement is vitally important for normal shoulder ROM
Shoulder Joint
Glenohumeral
- Glenoid fossa and humeral head
- Ball-in-socket
The Shoulder Capsule
- Capsule is ~2x larger than the humeral head
- Inferior portion is the weakest and is stretched out in order to stretch over the humeral head in full abduction or flexion
Glenohumeral Ligaments
- Superior Glenohumeral Ligament
- Middle Glenohumeral Ligament
- Inferior Glenohumeral Ligament
- Inferior band has to give out for a dislocation to occur
- 3 of the 4 bands are anterior and help limit ER and create more anterior stability
Superior Glenohumeral Ligament
Resists inferior translation when the arm is hanging or adducted
Middle Glenohumeral Ligament
- Some help with inferior translation when the arm is adducted
- Helps resist anterior translation (max effect is at about 45 degrees of abduction)
Inferior Glenohumeral Ligament
- Anterior Band
- Posterior Band
- Anterior stabilization in 90 degree abduction
- Tightens when the arm is abducted and externally rotated and cradles inferior head
- This is theorized to also add to the posterior/superior shift of the humeral head in throwing
When would the superior glenohumeral ligament tighten more than the others?
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Movements of the scapula
- Elevation/depression
- Abduction/adduction (protraction/retraction)
- Upward/Downward rotation
- Tipping
Scapular Elevation/Depression
10-12 cm
Protraction/Retraction
15 cm
Rotation
60 degrees
Tipping
- The scapula tilts forward around a frontal axis as it reaches the top of elevation
- Occurs due to the natural curvature in the spine and rib cage
Resting Position of the Scapula
- Between the 2nd through 7th ribs
- 2 inches from the midline
- Does not lie in the frontal plane (Wings 30-45 degrees towards sagittal)
Winging
When the scapula moves around the thorax
Abnormal Winging
- When the vertebral border moves posteriorly away from the wall of the thorax
- Usually caused by a problem with the long thoracic nerve
What ligaments restrict movement at the SC and make it so stable?
- Interclavicular ligament restricts superior movement
- Anterior/Posterior sternoclavicular ligament restrict anterior, posterior, and inferior movement
- It’s capsular reinforced
Ligament components of the AC joint
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Grades of Joint Separation
- 1 → damage to AC joint capsule and ligament
- 2 → joint capsule and trapezoid ligament
- 3 → joint capsule, trapezoid, and conoid ligament damage
What makes up the coracoacromial arch?
- Includes the anterior acromion, coracoacromial ligament and coracoid process
- Prevents superior dislocation
What is the labrum?
A fibrocartilaginous rim that helps to deepen the glenoid
Glenohumeral Labrum
- Almost triangular in shape and the bottom portion is firmly attached to the underlying bone
- The top portion has variable attachments, but is loosely connected
- The superior portion is attached to the biceps tendon (long head) as it connects at the supraglenoid tubercle
Changes in depth due to labrum
- Increases depth to 5 mm Ant/Post
- Increases depth to 9 mm Sup/Inf
- Depth is only 2.5 mm without the labrum
Deltoid
shoulder flexion, abduction, extension
Trapezius
scapular elevation
Supraspinatus
shoulder abduction
Infraspinatus
external rotation
Teres minor
external rotation
Teres major
internal rotation
Subscapularis
internal rotation
Serratus Anterior
scapular protraction
Latissimus Dorsi
adduction
Rhomboids
scapular retraction
Pectoralis minor
scapular depression
Coracobrachialis
shoulder flexion
Biceps (long head)
elbow flexion
Biceps (short head)
elbow flexion
Triceps (long head)
elbow extension
Levator Scapulae
scapular elevation
Omohyoid (inferior belly)
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Clavicle Movement
Elevation/Depression - Elevation → 45 degrees - Depression → 5-15 degrees Pro/Retraction - 15 degrees Rotation - 30-45 (posterior only) - The only time it moves anteriorly is to return to its resting position
Muscles of the Rotator Cuff
- Supraspinatus
- Ingraspinatus
- Teres minor
- Subscapularis
Insertions of the Rotator Cuff Muscles
Greater Tubercle
- SIT
Lesser Tubercle
- Subscapularis
Primary Forces of the Rotator Cuff and Shoulder Stability
- Rotator cuff helps offset the superior (or positive) pull of the deltoid
- Helps strengthen joint capsule and thus, indirectly help strengthen anterior and posterior capsular stability
- All the rotator cuff muscles help compress the humeral head into the glenoid
Rotator Cuff Test- Supraspinatus
Full can (80 degrees of flexion w/ horizontal abduction 30 degrees) with resistance against flexion
Rotator Cuff Test- Infraspinatus and Teres Minor
0 degrees abduction with arm in 45 degrees of internal rotation with resistance against external rotation
Rotator Cuff Test- Subscapularis Lower Fibers
- Lift off test
- Resistance to internal rotation with GH joint in extension and adduction with the hand behind the back.
Rotator Cuff Test- Subscapularis Upper Fibers
- Abdominal push test
- Patient pushes hand into abdomen. Look for humeral internal rotation. Substitution is humeral extension
Rotator Cuff Test- Sulcus Test
- Tests for inferior stability of the GH joint
- Positive test indicates laxity of the superior and middle glenohumeral and coracohumeral ligaments
- Positive when the sulcus below the acromion process is >1 fingers width
- Often present in patients with multidirectional instability
Hawkins and Kennedy Impingement Test
- Arm and elbow is flexed to 90 degrees, then forcibly internally rotated
- A positive test is pain and apprehension secondary to the rotator cuff tissues being impinged between the greater tubercle and coracoacromial arch
Clancy Impingement Test
- Arm abducted and elbow flexed 90 degrees
- Arm is adducted horizontally while internally rotating the arm and maintaining 90 degrees flexion
- A positive test is pain and apprehension as rotator cuff is impinged against the mid to anterior third of the acromion and the coracoacromial ligament
Neer and Walsh Impingement Test
- Arm is forcefully flexed causing a jamming of the greater tubercle against the anterior inferior acromial surface
- A positive test is pain, discomfort and/or apprehension secondary to a supraspinatus and/or biceps tendon pathology
External Impingement
- Common in general population
- Soft tissue is being pinched b/t the humerus and the acromion
- Includes tissue that is “external” to the capsule
Internal Impingement
- Pinching the rotator cuff tendons on the posterior glenoid within the capsule
- More common in throwers
SLAP Lesion
- SLAP Lesion = Superior Labral Anterior-Posterior Lesion
- It is a tear in the superior aspect of the labrum and is commonly associated with undersurface rotator cuff tears
Type I SLAP Lesion
- Fraying and degeneration of the superior labrum, normal biceps
- Most common type of SLAP tear
- Often associated with rotator cuff tears
- These are treated w/ debridement
Type II SLAP Lesion
- Detachment of the superior labrum and biceps insertion from the supraglenoid tubercle
- When traction is applied to the biceps, the labrum arches away from the glenoid
- Typically the superior and middle glenohumeral ligaments are unstable
- May resemble a normal variant
Subtypes of Type II SLAP Lesions
- Anterior
- Posterior
- Combined anteroposterior
Type III SLAP Lesion
- Bucket handle type tear
- Biceps anchor is intact
Type IV SLAP Lesion
- Vertical tear (bucket-handle tear) of the superior labrum, which extends into biceps
- May be treated w/ biceps tenodesis if more than 50% of the biceps tendon is involved
Biceps Tenodesis
Involves detaching the LHB from its superior labrum in the shoulder and reattached to the humerus bone just below the shoulder
What kind of lesion is more common in the general population?
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What kind of lesion is more common in the throwers?
Type II
What happens to the angle of torsion for people who throw a lot or have grown up and continue to pitch?
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Baseball stuff…
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