Trunk and Lower Back Muscles

Diaphragm

Expand thoracic cavity

Inferiorly compress abdominal viscera

External Intercostals

Elevate and Protract Ribs

Internal Intercostals

Depress and Retract Ribs

Transversus Thoracis

Depress Ribs

Serratus Posterior Superior

Elevate Ribs

Serratus Posterior Inferior

Depress Ribs

Longissimus Dorsi

Extend and Hyperextend trunk

Quadratus Lumborum

Extend and Laterally Flex Trunk

Rectus Abdominis

Flex Trunk

External Oblique

Superiorly compress abdominal contents in forced expiration

Contralateral rotation of waist

Internal Oblique

Superiorly compress abdominal contents in forced expiration

Ipsilateral rotation of waist

Transverse Abdominis

Superiorly compress abdominal contents in forced expiration

Pectoralis Major

Adduct, flex, and medially rotate arm

Serratus Anterior

Protract and Medially Rotate Shoulder

Trapezius

Elevate, Retract, and Laterally Rotate Shoulder

Levator Scapulae

Elevate and Retract Shoulder

Rhomboid Major

Retract Shoulder

Latissimus Dorsi

Adduct, Extend, and Medially Rotate arm

Deltoid

Flex, Abduct, and Rotate Arm

ORGIN =

Acromion and spine of scapula

Acromial (lateral) portion of clavicle

INSERTION =

Deltoid tuberosity of humerus

Supraspinatus (RC)

Abduct arm and stabilize shoulder

ORGIN =

Supraspinous Fossa

INSERTION =

Greater tubercle

Infraspinatus (RC)

Laterally rotate arm and stabilize shoulder

ORGIN =

Infraspinous fossa

INSERTION =

Greater Tubercle

Teres Minor (RC)

Laterally rotate arm and stabilize shoulder

ORGIN =

Lateral boarder of scapula

INSERTION =

Greater tubercle

Subscapularis (RC)

Medially rotate arm and stabilize shoulder

ORGIN =

Subscapular Fossa

INSERTION =

Lesser Tubercle

Biceps Brachii

Flex and Supinate Forearm

ORGIN =

short head - coracoid process

long head - superior aspect of glenoid fossa

INSERTION =

Olecranon Process

Brachialis

Flex Forearm

ORGIN =

Anterior aspect, humeral shaft

INSERTION =

Coronoid Process of Ulna

Triceps Brachii

Extend Forearm and Adduct Arm

ORGIN =

Long head - inferior aspect of glenoid fossa

Lateral head - Surgical neck of humerus

Medial head - Surgical neck of humerus

INSERTION =

Olecranon Process