Shoulder, Arm, Elbow Flashcards
Clavicle bone
- Articulates with axial skeleton via sternoclavicular joint
- Fractured frequently at middle 1/3 (S shape)
- Medial Joint = sternoclavicular joint
- Lateral Joint = acromioclavicular joint
Scapula Bone
- Attached to skeleton via muscles only
Humerus Bone (Proximal)
Joints
Sternoclavicular
Acromioclavicular
Glenohumeral
- Clavicle
- Manubrium of sternum
- NOT likely to disarticulate because anterior sternoclavicular ligament VERY strong > protects carotid arteries, superior vena cava, trachea
- Fractured frequently at middle 1/3 (S shape)
- Medial pulled up by sternocleidomastoid muscle
- Distal pulled down by gravity
- Treat with harness
Medial 1/3 clavicle fracture
Joints
Sternoclavicular
Acromioclavicular
Glenohumeral
- Clavicle
- Acromion process of scapula
- Weak joint capsule > synovial but no disc
- Coracoclavicular ligament =SUPPORT
- Shoulder separation at AC joint (falls)
- NOT shoulder dislocation
- With or without ligament rupture
- Shoulder separation at AC joint (falls)
- NOT shoulder dislocation
- With rupture (fall on shoulder)
- Without rupture (fall on elbows)
- Coracoclavicular ligament =SUPPORT
Glenohumeral Joint
- Humeral head
- Glenoid fossa of scapula
- “Round” head on “flat” socket
- Great movement
- Less stability
- Extra joint capsule at bottom
- 180 degree abduction
- Cartilage lip deepens socket
- Subacromial bursa
- Sac of synovial fluid
- Bursa: skin and muscle repeats
- Ie elbow bursa
- Repetitive motion > inflammation > bursitis
- Coracohumeral ligament = SUPPORT
- Weakest at inferior and anterior = glenohumeral dislocation
- Abduct, extend, external rotate > humeral head descends through labrum
Muscles
- Flexors
- Biceps
- Corachobrachialis
- Extensors
- Triceps long head
Glenohumeral Joint Fracture
- Coracohumeral ligament = SUPPORT
- Weakest at inferior and anterior = glenohumeral dislocation
- Abduct, extend, external rotate > humeral head descends through labrum
- Test sensation of axillary and musculocutaneous nerve
Rotator Cuff
- Supports glenohumeral joint medially and laterally > NO inferior support
- Supraspinatus
- Parallel to axis
- Doesn’t rotate
- Infraspinatus and Teres Minor
- Lateral rotation
- Subscapularis
- Medial rotation
- Rotator cuff tear
Rotator Cuff Tear
- Test: maintain 90 abduction against mild resistance
- Deltoid abducts to about 45 degrees only
Scapulohumeral Rhythm
Shoulder Movements
- Scapulohumeral Rhythm
- Joints of pectoral region move simultaneously in a coordinated way
- Arm elevation
- 3 degrees elevation
- 2 degrees glenohumeral joint
- Abduct, external rotate
- 1 degree scapula, SC, AC joint
Shoulder Muscles
- Prime movers of
- Scapula
- Humerus
- Stabilize glenohumeral joint
- Rotator Cuff (SITS)
- Supraspinatus (anterior)
- Infraspinatus (inferior)
- Teres Minor (inferior)
- Subscapularis (anterior)
Upward Rotation of Scapula
Trapezius upper and lower fibers elevate and depress > see-saw = cancel > just rotation
External Rotators of the Arm
Abductors of the Arm
Distal Humerus Bone
- Distal humerus
- Lateral epicondyle
- Medial epicondyle
- Median nerve
- Capitulum
- Fractures:
- Spiral groove of Shaft
- Radial nerve trauma
- Medial Supracondylar Ridge (distal)
- Median nerve trauma
- Spiral groove of Shaft
Proximal Radius and Ulna Bone
- Trochlear notch with coronoid process
Elbow Joint
- Capitulum and trochlea of humerus
- Head of radius
- Trochlear notch of ulna
- Flexion/Extension
- Elbow dislocation
- Coronoid process fracture> posterior dislocation
Muscles
- Flexors
- Biceps
- Brachialis
- Extensors
- Triceps-long, lateral, medial heads
- Supinator
- Biceps
- Elbow dislocation
- Coronoid process fracture> posterior dislocation
Radioulnar Joint
- Radius
- Annular ligament holds radius in place
- Ulna
- Pronation/supination
- Valgus stress
- Distal bones moved laterally at joint
- Strain at medial ligament
- MCL strain > Pitcher’s tear
- Radial dislocation
- Kids’ radial head = cartilage
Anterior compartment
Flexors
Musculocutaneous nerve
Brachial artery
Anterior compartment
Flexors
Musculocutaneous nerve
Brachial artery
Anterior compartment
Flexors
Musculocutaneous nerve
Brachial artery
Posterior compartment
Extensors
Radial nerve
Deep brachial artery
Posterior compartment
Extensors
Radial nerve
Deep brachial artery
Posterior compartment
Extensors
Radial nerve
Deep brachial artery
Cubital Fossa
- Superficial fascia
- Cubital vein anastomoses between cephalic and basilic veins
- Cubital fossa (deep to superficial fascia)
- Roofed over by the biciptal anopeurosis, protects median nerve and brachial artery
- Brachial artery > radial and ulnar artery in cubital fossa
- Radial nerve goes through the cubital fossa
- Ulnar nerve crosses posterior to the medical epicondyle of the humerus
