Muscles of the Trunk

ORIGIN: upper manubrium of sternum & upper border of medial clavical INSERTION: Mastoid process ACTION: unilateral (rotates head and face to opposite side with lateral flexion) & Bilateral (flex neck) NERVE: Accessory nerve (CN XI) and Branches of C2 -C3

ORIGIN: transverse process of cervical vertebrae INSERTION: First and second ribs ACTION: Bilaterally: assists in neck flexion Unilaterally: neck lateral bending NERVE: lower cervical nerve

ORIGIN: spinous processes C7 – T3 INSERTION: mastoid process; lateral occipital bone ACTION: Bilaterally: extend head and neck & Unilaterally: rotate and laterally bend head to same side NERVE: middle and lower cervical nerves

ORIGIN: spinous processes T3-T6 INSERTION: Transverse processes C1-C3 ACTION: bilaterally – extend neck/ unlaterally – rotate and laterally bend the neck to same side NERVE: middle and lower cervical nerves

ORIGIN: spinous processes, transverse processes, and ribs from the occiput to the sacrum and ilium INSERTION: spinous processes, transverse processes, and ribs from the occiput to the sacrum and ilium ACTION: bilaterally – extend/ unilaterally – laterally flex NERVE: spinal nerves

ORIGIN: Pubis INSERTION: xiphoid process and costal cartilages of ribs 5-7 ACTION: trunk flexion; compression of abdomen NERVE: 7th-12th intercostal nerves

ORIGIN: Ribs 5-12 INSERTION: iliac crest ACTION: bilaterally-trunk flexion and compression of abdomen/ unilaterally – lateral bending, rotation to opposite side NERVE: T7-T12 branches

ORIGIN: Iliac crest INSERTION: 10th-12th ribs ACTION: bilaterally- trunk flexion, compression of abdomen; unilaterally- lateral bending, rotation to same side NERVE: branches T7-T12

ORIGIN: thoracolumbar fascia; iliac crest, inguinal ligament, last 6 ribs INSERTION: abdominal aponeurosis and linea alba ACTION: compression of abdomen NERVE: branches of T1-T12

ORIGIN: Ribs 1-8 INSERTION: Vertebral border of scapula, anterior surface ACTION: scapular abduction and upward rotation NERVE: Long thoracic (C5-C7)

ORIGIN: C1-C4 transverse processes INSERTION: Scapula (vertebral border near superior angle) ACTION: scapular elevation NERVE: C3-C4

ORIGIN: Occipital bone, C1-C7 spinous processes INSERTION: outer third of clavicle and acromion process ACTION: scapular elevation and upward rotation NERVE: accessory

ORIGIN: C7-T3 spinous processes INSERTION: spine of scapula, medial end ACTION: scapular adduction (retraction) NERVE: accessory

ORIGIN: C7-T5 spinous processes INSERTION: vertebral border of the scapula ACTION: scapular adduction, elevation, and downward rotation NERVE: dorsal scapular

ORIGIN: T1-T5 vertebrae (spinous processes); supraspinous ligament T6-T12 vertebrae (spinous processes) INSERTION: base of scapular spine ACTION: scapular depression and upward rotation NERVE: accessory