back, chest, and abdominal region

extend & bend vertebral column laterally; fibers of longissimus also extend head

acting together, extend head & vertebral column acting independtly (right vs. left) causes rotation toward opposite side

• Function: prime mover of arm extension; adducts & medially rotates arm; brings arm down in power stroke as in striking a blow
• Origin: indirect attachment to spinous process of lower 6 vertebrae, lumbar vertebrae, last 3 to 4 ribs, and iliac crest
• Insertion: floor of intertubercular sulcus of humerus

each flexes vertebral column laterally; maintains upright posture

• Function: pull scapula medially (retraction)l stabilize scapula; rotate glenoid cavity downward (minor-retracts, adducts, stabilizes scapula; major-adducts, retracts, elevates, & rotaates scapula; stabilizes scapula)
• Origin: spinous processes of c7 and T1-T5
• Insertion: medial border of scapula

• Function: extends, medially rotates, & adducts humerus; synergist of latissimus dorsi
• Origin: posterior surface at inferior angle of scapula
• Insertion: intertubercular sulcus of humerus
• Location: superiorly to teres minor

• location: inferiorly to teres major
• Function: same as infraspinatus laterally rotation of humerus; helps hold head of humerus in glenoid cavity; stabilizes shoulder
• Origin: posterior surface at inferior angle of scapula
• Insertion: intertubercular sulcus of humerus

• Function: extends head, raises; rotates, & retracts (adducts) scapila & stabilizes it, elevates scapula
• Origin: occipital bone; ligamentum nuchae, spines of c7 and all thoracic vertebrae
• Insertion: acromion and spinous process of scapula; lateral third of clavicle

Function: prime mover of inspiration flattens on contraction

Function: pulls ribs toward one another to elevate rib cage; aid in inspiration

Function: draw ribs together to depress ribcage; aid in forced expiration

• Function: prime mover of arm flexion; adducts, medially rotates arm; with arm fixed, pulls chest upward (also acts in forced inspiration)
• Origin: clavicle, sternum, cartilage of ribs 1-6 (or 7), and aponeurosis of external oblique muscle
• Insertion: fibers converge to insert by short tendon into intertubercular sulcus of humerus

• Function: with ribs fixed, draws scapula forward & inferiorly & draws rib cage superiorly with scapula fixed
• Origin: anterior surface of ribs 3-5, near their costal cartilages
• Insertion: coracoid process of scapula

Function: prime mover to protract & hold scapula against chest wall, rotates scapula; abducts and stabilizes scapula

• Function: compresses abdominal wall, aids in muscles of back in trunk rotation & lateral flexion, flexes and rotates vertebral column
• Origin: anterior surface of last 8 ribs
• Insertion: linea alba, pubic crest & tubercles, and iliac crest

• Function: same as internal oblique
• Origin: lumbar fascia, iliac crest, & inguinal ligament
• Insertion: linea alba, pubic crest, & costal cartilages of last 3 ribs

formed by fusion of aponeurosis of external oblique & transversus muscles

• Function: flexes and rotates vertebral column; compresses anterior abdominal wall; flexes trunk
• Origin: pubic crest & symphysis
• Insertion: xyphoid process & costal cartilages of ribs 5-7

Function: depresses last 4 ribs

• Function: compresses anterior abdominal contents; pulls abdominal wall inward
• Origin: ribs 6-12 (costal cartilages & inner surfaces), illiac crest of illium (inner rim), inguinal ligament
• Insertion: pubis (crest/illippectineal line), andominal aponeurosis, linea alba

Function: the rectus abdominis is usually crossed by 3 fibrous bands liked by teninous inscriptions

Function: layers of flat broad tendons

Function: where the rectus abdominis is contained in

Function: extends vertebral column

Function: extends thoracis region

Function: extends cervical region

Function: extends lumbar region

Function: extends thoracis region

Function: extends cervical region