Origin • SP of the upper lumbar and lower thoracic vertebrae • Ligamentum nuchae Spinalis • SP of C7 Insertion • Sp of upper thoracic • SP of cervical, except C1 Action • Extension of the spine Longissimus • Lateral flexion of the spine Origin • TP C7-T9 • Thoracolumbar Aponeurosis Action Insertion • Extension of the spine • Mastoid process of the • Lateral Flexion of the spine temporal bone • TP C1-C6 • TP of all thoracic Vertebrae Origin • Posterior, superior surfaces of ribs 1-12 • Common Tendon (Thoracolumbar Action Iliocostalis aponeuroisis) • Extension of the spine • Lateral flexion of the spine Insertion • TP L1-3 • Posterior surface of all ribs • TP of lower cervicals Origin • Sacrum • TP of all vertebrae Multifidi Insertion • SP of all vertebrae: 2-4 vertebrae above origin Action • Extension of spine Rotatores • Rotation of spine to opposite side Origin • TP of all vertebrae Action • Rotation of spine to the Insertion opposite side • SP of all vertebrae, 1-2 • Extension of spine vertebrae above origin Origin • TP of C4-T5 Action Semispinalis • Extend the vertebral column Insertion and head • Occipital bone Origin • Inferior ½ of Ligamentum nuchae • SP of C7-T4 Splenius Capitis Insertion • Mastoid process • Occipital Bone Action • Extension of the head and neck • Lateral flexion of the head Splenius Cervicis and neck • Rotation of the head and neck to the same side Action Origin • Extension of the head and • TP of T3-T6 neck • Lateral flexion of the head Insertion and neck • TP of C1-C3 • Rotation of the head and neck to the same side Action • Lateral flexion of the lumbar Origin spine to the same side • Posterior Iliac Crest • Laterally tilt (elevate) the Quadratus Lumborum pelvis Insertion th • Assist to extend the vertebral • Inferior surface of 12 rib column • TP of L1-L4 • Fix the last rib during forced inhalation and exhalation Origin • Pubic crest • Pubic symphasis Rectus Abdominis Insertion • Costal Cartilage of 5th, 6th and 7th ribs • Xiphoid process Action • Flex the vertebral column External Oblique • Tilt pelvis posteriorly Action Origin • Lateral flexion of the trunk to • Lateral surface of ribs 5-12 same side • Rotate vertebral column to Insertion the opposite side • Anterior iliac crest • Flex the vertebral column • Abdominal aponeurosis • Compress abdominal contents Origin Action • Lateral inguinal ligament • Lateral flexion of the trunk to • Iliac crest the same side • Thoracolumbar fascia • Rotate vertebral column to Internal Oblique the same side Insertion • Flex the vertebral column • Internal surface of lower 3 • Compress abdominal ribs contents • Abdominal aponeurosis Origin • Lateral surfaces of ribs 5-12 Transverse Abdominis Insertion • Anterior Iliac Crest • Abdominal aponeurosis Action • Compress abdominal Serratus Posterior Superior contents Origin • SP of C7 to T3 Action • Elevate the ribs during Insertion inhalation • Posterior surface of second through fifth ribs Origin • SP of T12-L3 Action Serratus Posterior Inferior • Depress the ribs during Insertion exhalation • Posterior surface of ninth through twelfth ribs .