muscles of the Shoulder Flashcards
Subscapularis
O: Subscapular fossa of scapula
I: Lesser tubercle of humerus
N: Upper/lower subscapular nerves (C5 - C6)
F: Arm internal rotation;Stabilizes humeral head in glenoid cavity
Teres minor
O: Lateral border of scapula
I: Greater tubercle of humerus
N: Axillary nerve (C5, C6)
F: Arm external rotation/ Arm adduction
Supraspinatus
O: Supraspinous fossa of scapula
I: Greater tubercle of humerus
N: Suprascapular nerve (C5, C6)
F: Arm aBduction ‘empty can test’
Infraspinatus
O: Infraspinous fossa of scapula
I: Greater tubercle of humerus
N: Suprascapular nerve (C5, C6)
F: Arm external rotation
Deltoid
O: Lateral third of clavicle; Acromion of scapula: Spine of scapula I: Detoid tuberosity
N: Axillary nerve (C5-C6)
F: Arm flexion, Arm internal rotation (clavicular part), Arm abduction (acromial part), Arm extension, Arm lateral rotation (spinal part)
Teres Major
O: Inferior angle and lower part of lateral border of scapula
I: Crest of lesser tubercle of humerus
N: Lower subscapular or thoracodorsal nerves (C5- C7)
F: Shoulder joint: Arm internal rotation, Arm extension, Arm aDDuction
F:
Coracobrachialis
O: Coracoid process of scapula
I: Anteromedial surface of humeral shaft
N: Musculocutaneous nerve (C5 - C6)
F: Forearm flexion & supination;
Biceps Brachii
O: Long head: Supraglenoid tubercle of scapulaShort head:Coracoid process of scapula I: Radial tuberosity
N: Musculocutaneous nerve (C5 -C6
F: Forearm flexion and supination
Brachialis
O: Distal half of anterior surface of humerus
I: Ulnar tuberosity, Coronoid process of ulna
N: Musculocutaneous nerve Radial nerve (C5-C7)
F: Forearm flexion
Triceps
O: Long: Infraglenoid tubercle of scapula, L: Posterior surface of humerus, M: Posterior surface of humerus (superior/inferior radial groove) I: Olecranon of ulna
N: Radial nerve (C6 - C8)
F: Arm ext and adduction (long head); forearm ext
Anconeus
O: Lateral epicondyle of humerus
I: Lateral surface olecranon
N: Radial nerve (C7, C8)
F: Assists in forearm extension at the elbow/stabilisation
Muscles that Internally rotate the arm
Subscapularis, Teres Major, Pec major,
Latissimus Doris, Deltoid (anterior)
Muscles that externally rotate the arm at the shoulder
Teres Minor
Infraspinatus
Deltoid (posterior)
Muscles that ABDuct the shoulder
Supraspinatus
Deltoid
Muscles that ADDuct the shoulder
Pec Major
Coracobrachialis
Teres Major
Lattisimus
Muscles that flex the shoulder
Biceps (long head)
Pec Major
Deltoid
Coracobrachialis
Muscles that extend the shoulder
Teres Major, lattisimus Dorsi, Pec Major (to midline), Deltoid posterior, Triceps (long head)
Inserts on the greater tubercle of humerus
Teres Minor
Infraspinatus
Supraspinatus
Inserts on the lesser tubercle or humerus
Subscapularis
Teres Major
Upper Trapezius (descending)
O: S. Nuchal line/ligament, external occipital protuberance, cervical Vertebrae
I: lateral 1/3 of clavicle
N: Accessary nerve CN XI
F: elevates scapula, lateral/extension & flexion of the head & neck
Middle trapezius (transverse)
O: spinous process of T1-T4
I: medial acromion/crest of spine of scapula
N: Accessory nerve CX- X1
F: Draws scapula medially
Lower (Ascending) Trapezuis
O: Spinous process T5-T12
I: medial end of the of the spine of the scapula
N: Accessory nerve CN X1
F: Draws scapula inferomedially
Lavator Scapula
O: Transverse process vertebrae C1- C4
I: Medial border of scapula (superior angle to root spine of scapula)
N: Anterior rami of spinal nerve C3-C4 (Via cervical plexus)
F: cervical joints laterally flex the neck, rotates glenoid cavity inferiorly by rotating the scapula downwards
Rhomboid Major
O: T2- T5 (spinous process)
I: medial border of scapula (inferior to root spine)
N: Dorsal scapula nerve C5
F: Draws scapula superiomedially, rotates the glenoid cavity
