Muscles | Origin & Insertion

Subscapularis

Subscapularis

O: Subscapular fossa

I: Lesser tubercle of humerus

A: medial rotation

Infraspinatus

O: Infraspinous Fossa

I: Greater tubercle of humerus

A: Lateral Rotation

N: Brachial Plexus

Supraspinatus

O: Supraspinous Fossa

I: Greater tubercle of humerus

A: Abducts the arm

N: Brachial Plexus

Teres Minor

O: Lateral border of Scapula

I: Greater tubercle of humerus

A: Lateral Rotation

N: Brachial Plexus

Teres Major

O: Inferior angle of scapula

I: Intertubercular groove of humerus

A: Extension, medial rotation

N: Brachial plexus

Deltoid

O: Clavicle, Acromion process, Spine of scapula

I: Deltoid tuberosity

A: Abduction

N: Brachial plexus (Axillary nerve)

Trapezius

O: Vertebral column

I: Clavicle, Acromion process, Scapular spine

A: Elevation of scapula

N: Cervical plexus

Rhomboids

O: Spinous process of vertebrae (C6-C7)

I: Medial border of scapula

A: Adduction of scapula

N: Brachial plexus

Levator Scapulae

O: Transverse process (C1-4)

I: Superior angle of scapula

A: Elevation/Downward rotation of scapula

N: Brachial plexus

Erector Spinae

A: Extension of spine

I: Dorsal Rami of spinal nerves

Transversospinalis

O: Sacrum

I: Spinous process of vertebra

Splenius

O: C7 to T3-4

I: Mastoid Process

A: Neck extension or lateral bending

N: Dorsal Rami of cervical nerves

Serratus Anterior

O: Ribs 1-8 or 9

I: Medial border of scapula

A: protract scapula

N: Long thoracic nerve of brachial plexus

Latissimus Dorsi

O: Ribs 8-12 and spinous processes of lower thoracic/lumbar vertebrae

I: Intertubercular groove

A: Extension, medial rotation of arm

N: Brachial plexus

Pectoralis major

O: Sternum, ribs -6, clavicle

I: Greater tubercle of humerus & Intertubercular groove

A: Adduction and medial rotation of arm

N: Brachial plexus

Pectoralis minor

O: ribs 3-5

I: Coracoid process of scapula

A: Protract scapula

N: Brachial plexus

Brachialis

O: Anterior mid-distal humerus

I: Ulnar tuberosity

A: Elbow Flexion

N: Brachial plexus (Musculotcuaneous nerve)

Brachioradialis

O: Above lateral epicondyle on distal humerus

I: Styloid Process of radius

A: Elbow flexion

N: BP( radial nerve)

Biceps Brachii

O: Supraglenoid tubercle (Long head) & Coracoid process (Short head)

I: Radial tuberosity

A: Flexion of arm at shoulder & elbow

N: BP (Musculocutaneous)

Coracobrachialis

O: Coracoid process of scapula

I: Diaphysis of humerus

A: Flexion of arm at shoulder, arm adduction

N: BP (Musculocutaneous)

Triceps Brachii

O: Lateral head (lat humerus), Medial head (med humerus), Long head (infraglenoid tubercle)

I: Olecranon process

A: Extension of arm at shoulder and elbow

N: Radial nerve

Common flexors

O: Medial epicondyle

I: Carpals, metacarpal, phalanges

A: Wrist and digit flexion

I: BP (ulnar and median)

Common Extensors

O: Lateral epicondyle

I: Carpals, metacarpals, phalanges

A: extension of wrist and digits

N: radial nerve