Shoulder (Week 8) Flashcards
GHJ Contractile structures that limit
excessive movement
Rotator cuff muscles
Dynamic ligaments
GHJ Non-Contractile structures that limit
excessive movement
Glenoid labrum
Ligaments
Glenoid Labrum function
- Deepens socket
- Limit accessory movement
- Increases congruency of GHJ
- Attachment for long head of biceps
at the superior edge - Labrum can be torn in dislocations
or from biceps traction - 59% of 1st time GHJ dislocations will
include a Bankart lesion (anterior
tear to labrum)
GLENOHUMERAL Ligament functions
- Thickenings of
capsule - Limits anterior
accessory movt
in external
rotation - IGHL anterior in
a stop sign
position
Coracohumeral ligament Function
Resists weight of arm
Keeps ball in socket
Transverse humeral ligament Function
Converts intertubercular sulcus
into the bicipital tunnel.
Prevents bowstring of biceps
tendon
Holds synovial sheath around
biceps in place
Deltoid Att.
P: 3 heads
1. lateral 1/3 clavicle (anterior),
2. acromion (middle),
3. scapula spine (posterior)
D: deltoid tuberosity of humerus
Deltoid A/NS
Action: ABD (strong), FL, EXT GHJ
Function: resist downward weight of arm.
NS: Axillary Nerve
Rotator Cuff Muscles/Functions
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
STABILISE THE HUMERAL HEAD
IN THE GLENOID FOSSA
BALANCE DELTOID FORCES
Supraspinatus Att
P: supraspinous fossa
D: greater tubercle of humerus (superior)
Supraspinatus A/NS
Action: initiates & assists ABD in GHJ
Function: stabilise head of humerus in glenoid
fossa
NS: Suprascapular nerve
Infraspinatus Att
P: infraspinous fossa
D: greater tubercle of humerus (middle)
Infrapsinatus A/NS
Action: external rotation of GHJ
Function: stabilise head of humerus in
glenoid fossa
NS: Suprascapular nerve
Teres Minor Att.
P: middle part lateral border scapula
D: greater tubercle of humerus (inferior)
Teres Minor A/NS
Action: external rotation of GHJ
Function: stabilise head of humerus in
glenoid fossa
NS: Axillary nerve
Supscapularis Att.
P: subscapular fossa
D: lesser tubercle of humerus
Subscapularis A/NS
Action: medial rotation of GHJ
Function: stabilise head of humerus
in glenoid fossa
NS: upper and lower subscapular nerve
Teres Major Att.
P: posterior surface of inferior angle of scapula
D: medial lip intertubercular sulcus of humerus
Teres Major A/NS
Action: ADD & medial rotation of GHJ
NS: Lower subscapular nerve (C5-6)
Axillary Nerve Source
C5-6
Axillary Nerve Course
From the cord of the brachial plexus
Lateral to radial nerve, posterior to the
axillary artery
Passes into the axilla
Passes through quadrangular space
Curves around the neck of the
humerus
Axillary Nerve Motor Supply
Teres minor
Deltoid
Axillary Nerve Sensory Supply
patch over Deltoid laterally
Biceps Brachii Att.
Proximal:
Long head: supraglenoid tubercle of
the scapula
Short head: coracoid process of
scapula
Distal: radial tuberosity
Biceps Brachii A/NS
Action: forearm supination and elbow
flexion; shoulder flexion
NS: musculocutaneous nerve
Coracobrachilais Att.
P: coracoid process of scapula
D: medial surface of humerus
Coracobrachialis A/NS
Action: shoulder flexion and adduction
NS: musculocutaneous nerve
Brachialis Att.
P: anterior surface of distal humerus
D: coronoid process and ulnar
tuberosity
Brachialis A/NS
Action: elbow flexion
NS: musculocutaneous and radial nerve
Musculocutaneous Nerve Source
C5-7
Musculocutaneous Nerve Course
Arises from cord of brachial plexus
Pierces coracobrachialis and descends laterally
between biceps brachii and brachialis at the
lateral arm
Pierces the deep fascia in the cubital fossa
lateral to the tendon of biceps brachii
Continues as the lateral cutaneous nerve of the
forearm
Musculocutaneous Nerve Motor Supply
- biceps brachii
– brachialis
– coracobrachialis
Musculocutaneous Nerve Sensory Supply
– lateral cutaneous nerve of the
forearm
