Muscles of the TrunkVersión en línea Labeling, actions, origins, and insertions of the trunk muscles por Sophie Peck 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Explanation 2 laterally rotates trunk 5 Compresses abdominal wall; flexes vertebral column; trunk flexion 6 Origin: Clavicle and sternum Insertion: Greater Tubercle of humerus Action: Shoulder flexion; flexes arm; shoulder adduction; adducts arm; shoulder internal rotation; rotates arm medially 7 elevates clavicle and scapula 8 Origins: T7-T11, L1-L5, S1-S5; Crest of Ilium Insertion: Intertubercular groove of humerus Action: Shoulder extension; extends arm; shoulder adduction; adducts arm; shoulder internal rotation; medially rotates arm 12 Origin: supraspinous fossa of scapula Insertion: greater tubercle of humerus Actions: Shoulder abduction; abducts arm 13 scapula retraction; adducts scapula