Innervations
| Muscle | Attaches | Actions | Nerve supply |
| Trapezius | base of skull, the spines of all cervical and thoracic vertebrae to the clavicle, inner edge of the acromion; upper edge of the spine of the scapula |
elevation of shoulder as in shrugging and retraction of scapula | cranial nerve XI (accessory) and C3 and C4 |
| Serratus Anterior | ribs 1 - 8 to the vertebral border of the scapula | powerful protraction of the scapula. Its lower portion rotates the scapula and causes abduction of the arm from 90 to 180 degrees |
long thoracic nerve (nerve to the serratus) (C5 - C7) |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
axillary nerve (C5 - C6) |
| Teres minor | lateral border of scapula to the inferior facet of greater tuberosity | external rotation | axillary nerve |
Pectoralis Major
|
clavicle, sternum, and front of ribs to lateral lip of bicipital groove | powerful adduction and medial rotation of humerus | lateral and medial pectoral nerves (C5 - T1) |
| Pectoralis Minor | ribs 3, 4, and 5 to coracoid process | depression of glenoid with rotation downward and forward | medial pectoral nerve (C8, T1)
|
| Coracobrachialis | tip of coracoid to medial mid-shaft of humerus | weak adduction and flexion at shoulder joint | Musculocutaneous |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
| Brachialis | lower half of the anterior humeral shaft to coronoid of ulna | powerful flexion of elbow joint | Musculocutaneous |
| Triceps | long head from the infraglenoid tubercle; medial and lateral heads from the back of the humerus on either side of spiral groove; all three heads attach to the olecranon of the ulna | extension of the elbow joint | radial nerve |
| Supraspinatus | supraspinous fossa to upper facet of greater tuberosity | first 15-20 degrees of abduction | suprascapular nerve |
| Infraspinatus | infraspinous fossa to middle facet of greater tuberosity | external rotation | suprascapular nerve
|
| Levator scapulae | from transverse processes of first four cervical vertebrae to upper vertebral border of scapula | retraction of scapula and rotation of glenoid downward | dorsal scapular nerve (nerve to rhomboids) and C3 and C4 |
| Rhomboid major and minor | spinous processes of C7 - T5 to medial border of scapula | retraction of scapula and rotation of glenoid downward | dorsal scapular nerve (nerve to rhomboids) |
| Latissimus dorsi | spines of lower 6 thoracic vertebrae, the lumbar and sacral fascia to floor of the bicipital groove of the humerus |
adduction and medial rotation of the arm at the shoulder | thoracodorsal nerve (middle subscapular nerve) (C6 - C8) |
| Teres major | back of lateral border of scapula to medial lip of the bicipital groove of humerus | adduction and medial rotation of arm at the shoulder | lower subscapular nerve |
| Subscapularis | subscapular fossa to lesser tuberosity | medial rotation | upper and lower subscapular nerves |
Actions
| Muscle | Attaches | Actions | Nerve supply |
| Latissimus dorsi | spines of lower 6 thoracic vertebrae, the lumbar and sacral fascia to floor of the bicipital groove of the humerus |
adduction and medial rotation of the arm at the shoulder | thoracodorsal nerve (middle subscapular nerve) (C6 - C8) |
| Teres major | back of lateral border of scapula to medial lip of the bicipital groove of humerus | adduction and medial rotation of arm at the shoulder | lower subscapular nerve |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Subscapularis | subscapular fossa to lesser tuberosity | medial rotation | upper and lower subscapular nerves |
Pectoralis Major
|
clavicle, sternum, and front of ribs to lateral lip of bicipital groove | powerful adduction and medial rotation of humerus | lateral and medial pectoral nerves (C5 - T1) |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Infraspinatus | infraspinous fossa to middle facet of greater tuberosity | External rotation | suprascapular nerve
|
| Teres minor | lateral border of scapula to the inferior facet of greater tuberosity | external rotation | Axillary nerve |
| Trapezius | base of skull, the spines of all cervical and thoracic vertebrae to the clavicle, inner edge of the acromion; upper edge of the spine of the scapula |
elevation of shoulder as in shrugging and retraction of scapula | cranial nerve XI (accessory) and C3 and C4 |
| Levator scapulae | from transverse processes of first four cervical vertebrae to upper vertebral border of scapula | retraction of scapula and rotation of glenoid downward | dorsal scapular nerve (nerve to rhomboids) and C3 and C4 |
| Rhomboid major and minor | spinous processes of C7 - T5 to medial border of scapula | retraction of scapula and rotation of glenoid downward | Dorsal scapular nerve (nerve to rhomboids) |
| Pectoralis Minor | ribs 3, 4, and 5 to coracoid process | depression of glenoid with rotation downward and forward | Medial pectoral nerve (C8, T1)
|
| Serratus Anterior | ribs 1 - 8 to the vertebral border of the scapula | powerful protraction of the scapula. Its lower portion rotates the scapula and causes abduction of the arm from 90 to 180 degrees | long thoracic nerve (nerve to the serratus) (C5 - C7) |
| Levator scapulae | from transverse processes of first four cervical vertebrae to upper vertebral border of scapula | retraction of scapula and rotation of glenoid downward | dorsal scapular nerve (nerve to rhomboids) and C3 and C4 |
| Rhomboid major and minor | spinous processes of C7 - T5 to medial border of scapula | retraction of scapula and rotation of glenoid downward | dorsal scapular nerve (nerve to rhomboids) |
| Trapezius | base of skull, the spines of all cervical and thoracic vertebrae to the clavicle, inner edge of the acromion; upper edge of the spine of the scapula |
elevation of shoulder as in shrugging and retraction of scapula | cranial nerve XI (accessory) and C3 and C4 |
| Coracobrachialis | tip of coracoid to medial mid-shaft of humerus | weak adduction and flexion at shoulder joint | Musculocutaneous |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Supraspinatus | supraspinous fossa to upper facet of greater tuberosity | first 15-20 degrees of abduction | suprascapular nerve |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Serratus Anterior | ribs 1 - 8 to the vertebral border of the scapula | powerful protraction of the scapula. Its lower portion rotates the scapula and causes abduction of the arm from 90 to 180 degrees |
long thoracic nerve (nerve to the serratus) (C5 - C7) |
| Latissimus dorsi | spines of lower 6 thoracic vertebrae, the lumbar and sacral fascia to floor of the bicipital groove of the humerus |
adduction and medial rotation of the arm at the shoulder | thoracodorsal nerve (middle subscapular nerve) (C6 - C8) |
| Teres major | back of lateral border of scapula to medial lip of the bicipital groove of humerus | adduction and medial rotation of arm at the shoulder | lower subscapular nerve |
Pectoralis Major
|
clavicle, sternum, and front of ribs to lateral lip of bicipital groove | powerful adduction and medial rotation of humerus | lateral and medial pectoral nerves (C5 - T1) |
| Coracobrachialis | tip of coracoid to medial mid-shaft of humerus | weak adduction and flexion at shoulder joint | Musculocutaneous |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
| Brachialis | lower half of the anterior humeral shaft to coronoid of ulna | powerful flexion of elbow joint | Musculocutaneous |
| Triceps | long head from the infraglenoid tubercle; medial and lateral heads from the back of the humerus on either side of spiral groove; all three heads attach to the olecranon of the ulna | extension of the elbow joint | radial nerve |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
Attachments
| Muscle | Attaches | Actions | Nerve supply |
| Trapezius | base of skull, the spines of all cervical and thoracic vertebrae to the clavicle, inner edge of the acromion; upper edge of the spine of the scapula |
elevation of shoulder as in shrugging and retraction of scapula | cranial nerve XI (accessory) and C3 and C4 |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
axillary nerve (C5 - C6) |
| Trapezius | base of skull, the spines of all cervical and thoracic vertebrae to the clavicle, inner edge of the acromion; upper edge of the spine of the scapula |
elevation of shoulder as in shrugging and retraction of scapula | cranial nerve XI (accessory) and C3 and C4 |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
Axillary nerve (C5 - C6) |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
| Triceps | long head from the infraglenoid tubercle; medial and lateral heads from the back of the humerus on either side of spiral groove; all three heads attach to the olecranon of the ulna | extension of the elbow joint | radial nerve |
| Supraspinatus | supraspinous fossa to upper facet of greater tuberosity | first 15-20 degrees of abduction | suprascapular nerve |
| Infraspinatus | infraspinous fossa to middle facet of greater tuberosity | external rotation | suprascapular nerve
|
| Subscapularis | subscapular fossa to lesser tuberosity | medial rotation | Upper and lower subscapular nerves |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
axillary nerve (C5 - C6) |
Pectoralis Major
|
clavicle, sternum, and front of ribs to lateral lip of bicipital groove | powerful adduction and medial rotation of humerus | lateral and medial pectoral nerves (C5 - T1) |
| Pectoralis Minor | ribs 3, 4, and 5 to coracoid process | depression of glenoid with rotation downward and forward | medial pectoral nerve (C8, T1)
|
| Coracobrachialis | tip of coracoid to medial mid-shaft of humerus | weak adduction and flexion at shoulder joint | Musculocutaneous |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
Pectoralis Major
|
clavicle, sternum, and front of ribs to lateral lip of bicipital groove | powerful adduction and medial rotation of humerus | lateral and medial pectoral nerves (C5 - T1) |
| Latissimus dorsi | spines of lower 6 thoracic vertebrae, the lumbar and sacral fascia to floor of the bicipital groove of the humerus |
adduction and medial rotation of the arm at the shoulder | thoracodorsal nerve (middle subscapular nerve) (C6 - C8) |
| Teres major | back of lateral border of scapula to medial lip of the bicipital groove of humerus | adduction and medial rotation of arm at the shoulder | lower subscapular nerve |
| Teres minor | lateral border of scapula to the inferior facet of greater tuberosity | external rotation | axillary nerve |
| Supraspinatus | supraspinous fossa to upper facet of greater tuberosity | first 15-20 degrees of abduction | suprascapular nerve |
| Infraspinatus | infraspinous fossa to middle facet of greater tuberosity | external rotation | suprascapular nerve
|
| Subscapularis | subscapular fossa to lesser tuberosity | medial rotation | upper and lower subscapular nerves |
| Deltoid | from clavicle, acromion, and spine of scapula to the deltoid tuberosity of humerus | Anchors arm to girdle Central portion: abduction of the shoulder from 15 to 90 degrees Anterior fibers: flexion and medial rotation of humerus Posterior fibers: extension, and lateral or external rotation of humerus |
axillary nerve (C5 - C6) |
| Biceps brachii | short head from tip of coracoid; long head from the supraglenoid tubercle, passing through the shoulder joint; both heads to radial tuberosity | flexion of the shoulder, flexion of elbow, and supination of the forearm | Musculocutaneous |
| Brachialis | lower half of the anterior humeral shaft to coronoid of ulna | powerful flexion of elbow joint | Musculocutaneous |
| Triceps | long head from the infraglenoid tubercle; medial and lateral heads from the back of the humerus on either side of spiral groove; all three heads attach to the olecranon of the ulna | extension of the elbow joint | radial nerve |