Intrinsic Pt.1
What is the innervation of the deltoid?
Axillary nerve (C5/C6)
What is the distal attachment for the supraspinatus?
Superior facet of greater tubercle of humerus
What is the innervation for the supraspinatus?
Suprascapular nerve (C4/C5/C6)
What are the prime movers flexion?
- Pec major (clavicular head)
- Deltoid (clavicular/anterior)
What is the prime mover in abduction?
Deltoid
What is the proximal attachment for the supraspinatus?
Supraspinous fossa of scapula
What is the muscle action of the subscapularis?
Medially (internal) rotation
What is the proximal attachment for the deltoid?
Lateral third of clavicle/acromion/spine of scapula
What are the two synergists for adduction?
- Long head of biceps brachii
What are the synergists with medial rotation?
- Pec major
- Deltoid (clavicular part)
- Latissimus dorsi
- Teres major
What is the teres major muscle action?
Adducts & medially rotates arm
What is the proximal attachment for the teres major?
Posterior surface of inferior angle of scapula
What is the proximal attachment of the subscapularis?
Subscapular fossa of scapula
What are the prime movers for tensors of the articular capsule?
- Subscapularis/infraspinatus simultaneously
What is the synergist with flexion?
Coracobrachialis
What is the distal attachment for the subscapularis?
Lesser tubercle of humerus
What is the innervation of the teres minor?
Axillary nerve (C5/C6)
What is the main action of the teres minor?
Laterally (external) rotates arm
What is the prime mover in extension?
Deltoid (spinal/posterior) part
What are the synergists when resisting downward dislocation?
- Long head of triceps brachii
- Coracobrachialis
- Short head of biceps brachii
What is the distal attachment for the teres minor?
Inferior facet of greater tubercle of humerus
What are the muscle actions of the deltoid?
- Clavicular (anterior): flexes & medially rotates arm
- Acromial (middle): abducts arm
- Spinal (posterior): extends & laterally rotates arm
What is the distal attachment & innervation of the infraspinatus?
Middle facet of greater tubercle of humerus + suprascapular nerve
What are the synergists with lateral rotation?
- Teres minor
- Deltoid (spinal/posterior) part
What are the synergists of extension?
- Teres major
- Latissimus dorsi
- Long head of triceps brachii