Shoulder test 3 principals of AT

Sternum

Breastbone; contains manubrium; forms SC joint (only attachment of upper extremity to trunk)

Clavicle

S-shaped collarbone; prevents shoulder from collapsing; most fractures occur in middle 1/3

Scapula

Shoulder blade; contains acromion, coracoid process, spine, and glenoid fossa

Glenoid fossa

Shallow socket on scapula; articulates with humerus; unstable

Humerus

Upper arm bone; head fits into glenoid fossa forming GH joint

Surgical neck (humerus)

Most common fracture site of humerus

Greater tubercle

Lateral; supraspinatus attaches

Lesser tubercle

Medial; subscapularis attaches

Bicipital groove

Groove where long head of biceps tendon runs

SC joint

Sternum + clavicle; very stable; only connection to trunk

AC joint

Acromion + clavicle; common injury site

GH joint

Glenoid fossa + humerus; highly mobile, unstable

Sternoclavicular ligament

Stabilizes SC joint

Costoclavicular ligament

Connects clavicle to first rib

Interclavicular ligament

Connects both clavicles

AC ligament

Stabilizes AC joint; commonly injured first

Coracoclavicular ligament

Provides major stability to shoulder

Trapezoid ligament

Lateral part of coracoclavicular; first to rupture

Conoid ligament

Medial part of coracoclavicular

Coracoacromial ligament

Forms arch over shoulder; NOT for stability

Flexion

Arm moves forward

Extension

Arm moves backward

Abduction

Arm moves away from body

Adduction

Arm moves toward body

Internal rotation

Arm rotates inward

External rotation

Arm rotates outward

Elevation

Shoulder shrug

Depression

Lowering shoulders

Abduction (upward rotation)

Scapula rotates upward

Adduction (downward rotation)

Scapula rotates downward

Mechanism (Sc joint)

Fall on shoulder or direct force

Anterior dislocation (Sc joint)

Visible deformity

Sprain (Sc joint)

Most common injury

Posterior dislocation (Sc joint)

Dangerous; may affect trachea and blood vessels

Treatment (Sc joint)

Retract scapula, ice, immobilize, refer

Mechanism (clavicle fracture)

Fall on outstretched arm (most common)

Location (Clavicle fracture)

Middle 1/3 most common

Signs (Clavicle fracture)

Deformity, pain, swelling

Treatment → Ice, X-ray, sling or clavicle brace

Involved ligaments (Ac joint sprain)

AC ligament and coracoclavicular ligament

AC ligament tear only

Shoulder still stable

Coracoclavicular tear (ac joint sprain)

Loss of structural integrity

Trapezoid ligament (Ac joint sprain)

First to rupture

Subscapularis origin

Subscapular fossa (front of scapula)

Subscapularis insertion

lesser tubercle of humerus

Subscapularis actions

Medial (internal) rotation

Stabilizes shoulder

Subscapularis (key note)

ONLY rotator cuff muscle that does internal rotation

Supraspinatus origin

Supraspinous fossa

Supraspinatus insertion

Greater tubercle (top)

Supraspinatus actions

Abducts arm (first ~15°)

Stabilizes shoulder

Supraspinatus (Key)

Starts abduction

Infraspinatus origin

Infraspinous fossa

infraspinatus insertion

Greater tubercle (middle)

infraspinatus actions

External (lateral) rotation

Stabilizes shoulder

Teres Minor origin

Lateral border of scapula

Teres minor insertion

Greater tubercle (bottom)

Teres minor actions

External (lateral) rotation

Stabilizes shoulder

Direct trauma (ac joint)

Fall on shoulder forcing acromion downward (most common)

Indirect trauma (ac joint)

Fall on outstretched hand transmitting force upward

1st degree AC sprain

AC ligament only; pain; no deformity; no clavicle elevation; minimal ROM loss

2nd degree AC sprain

AC torn + partial coracoclavicular; swelling; limited ROM; slight clavicle elevation; positive spring test

3rd degree AC sprain

AC + coracoclavicular torn; severe pain; obvious deformity; clavicle elevated; positive spring test

Spring test

Push clavicle down; it rebounds upward

GH joint stability

Determined by rotator cuff (not bones)

Strain (GH joint)

Injury to the rotator cuff or surrounding muscles

Subluxation (GH joint)

Partial displacement; more common; ligaments stretched

Dislocation (GH joint)

Full displacement; MOI = abduction + external rotation

First-time dislocation (Gh joint)

Do NOT reduce; immobilize

Immobilization time (GH joint)

3 weeks (prevents atrophy and reinjury)

Apprehension test (GH joint)

Detects anterior shoulder dislocation; positive with pain/fear

Rotator cuff function

Stabilizes humeral head; decelerates arm

causes of injury (rotator cuff)

Overstretch, violent contraction, overuse

Impingement (rotator cuff)

Compression during overhead motion

Structures affected in impingement (rotator cuff)

Subacromial bursa, long head of biceps tendon, rotator cuff

Painful arc (rotator cuff)

Pain in the middle range of motion

Empty can test (rotator cuff)

tests supraspinatus (abduct, internally rotate, resist downward pressure)

Transverse humeral ligament

Holds biceps tendon in groove

Biceps tenosynovitis

Inflammation of tendon sheath

Subluxing biceps tendon

Tendon slips out due to ligament damage

Yergason's test

Detects biceps tendon pathology; positive with pain or tendon movement