Shoulder Muscles

Subscapularis

O: Subscapular fossa
I: lesser tubercle of Humerus
N: subscapular
A: Stabilization, medial rotation of humerus

Supraspinatus

O: Supraspinous fossa
I: Greater tubercle of humerus
N: Suprascapular
A: Stabilization, abduction

Infraspinatus

O: Infraspinous fossa of scapula
I: Greater tubercle of humerus
N: Suprascapular
A: Stabilization, Lateral rotation of humerus

Teres Minor

O: Lateral border of scapula
I: Greater tubercle of humerus
N: Axillary
A: Stabilization, lateral rotation of humerus

Coracobrachialis

O: Coracoid process of scapula
I: medial shaft of humerus
N: Musculocutaneous
A: Shoulder flexion, adduction, horizontal adduction

Anterior Deltoid

O: lateral clavicle
I: Deltoid tuberosity of humerus
N: Axillary
A: Shoulder flexion, Abduction, medial rotation, horizontal adduction

Latissimus Dorsi

O: Spinous processes of lower thoracic and lumbar vertebra, ribs 8-12, lumbodorsal fascia
I: floor of intertubercular groove
Innervation: Thoracodorsal
A: Extension, adduction, medial rotation, horizontal abduction

Teres Major

O: Acromion process of scapula
I: Deltoid tuberosity of humerus
N: Axillary
A: Abduction

Serratus Anterior

O: Anterior shaft of ribs 1-9
I: Vertebral border of scapula
N: Long thoracic
A: Scapular abduction, upward rotation (inf. Fibers)

Subclavis

O: Medial first rib
I: lateral clavicle
N: Subclavian
A: Downward rotation, abduction of scapula
Also, ‘dynamic ligament’ at sternoclavicular jt.

Rhomboid Minor

O: Spinous processes of C7-T1 vertebrae
I: Vertebral border of scapula near spine
N: Dorsal scapular
A: Adducts and downward rotation

Rhomboid Major

O: Spinous processes of upper thoracic vertebrae
I: Vertebral border of scapula below spine
N: Dorsal scapular
A: Adducts and downward rotation

Levator scapulae

O: Transverse processes of C1-C4
I: Superior angle of scapula
N: Cervical nerves C3-C4 & dorsal scapular (C5)
A: Elevates scapula, downward rotation.

Trapezius

Origin: Occipital bone, spinous processes of cervical and thoracic vertebra
Insertion: Scapula
I. Clavicle
II. Acromion process
III. Spine of scapula
IV. Medial portion of scapular spine
Innervation: Accessory (CN XI)
Action: Upward rotation, elevation, depression, adduction, & extension of neck

Triceps Brachii, Long Head

O: Infraglenoid tubercle of scapula
I: Olecranon process of ulna
N: Radial
A: Shoulder extension, adduction, horizontal abduction

Posterior Deltoid

O:Spine of scapula
I: Deltoid tuberosity of humerus
N: Axillary
A: extension, lateral rotation, abduction, horizontal abduction

Middle Deltoid

O: Acromion process of scapula
I: Deltoid tuberosity of humerus
N: Axillary
A: Abduction

Pectoralis Minor

O: Ventral surfaces of ribs 3-5
I: Coracoid process of scapula
N: Medial pectoral
A: Downward rotation, abduction, anterior tilt, depression, & forced inspiration of ribs

Pectoralis Major

O:Medial clavicle, sternum, & cartilages of ribs 2-6
I: Lateral lip of intertubercular groove
N: Medial and lateral pectoral
A: Horiz. Add. (horiz. Flex.), medial rotation, flexion, extension, adduction

Biceps Brachii

O: SH: coracoid process, LH: supraglenoid tubercle
I: Radial tuberosity
N: Musculocutaneous
A: Shoulder flexion, SH:adduction, *LH:abduction *, horizontal adduction