Student Name Instructor Course Title Date due: Origin, Insertion, Action, and Innervation of Muscles Muscle Name Origin Insertion Action Innervation Rectus Abdominas Pubic crest, Pubic sympysis; occur around the pelvic bone Costal cartilage (5th, 6th, 7th ribs), Xiphloid process of the sternum. Causes rib cage and Pelvis to lean into the middle of the abdomen. Lower six thoraco-abdominal nerves Erector Spinae Sacrum, ilium, thoracic vertebrae, ribs Thoracic and cervical vertebrae, ribs, skull Extension of neck and trunk, rotation of head, maintaining body posture Dorsal Rami of cervical, thoracic, and lumbar spinal nerves Pectoralis Major Clavicle head-medial half, Sternal head- outer sternum, upper six coastal cartilages. Lateral lip of the bicipital groove of the humerus and deltoid tuberosity Shoulder flexion, internal rotation and adduction of the humerus, draw scapula anteriorly and inferiorly. Medial and lateral pectoral nerve Serratus Anterior Lateral superior eight ribs, anterior intercostal membrane, lower four slips adjacent to the abdominal oblique Costal aspect of the medial border of the scapula Upward rotation and protraction of the scapula. Long thoracic nerve (C5, 6, 7) Rhomboid Major Spinous process of the (T2-T5) vertebrae. Scapula Rotates retracts and moves scapula to the thoracic wall. Dorsal scapular nerve Rhomboid minor Nuchal ligament (C7-T1) Scapula Rotates, retracts and fix scapula to the body wall Dorsal scapular nerve Latissimus Dorsi Spinous process (T7-T12), Inferior ribs, thoracolumbar fascia, iliac crest Intertubercular groove of the humerus Extension and rotation of the arm, adduction, medial rotation of the humerus.