Deep Muscles of the Spine

Vocabulary-style flashcards covering the origins, insertions, and actions of the deep muscles of the spine based on the lecture transcript.

DPR

Dorsal primary rami.

VPR

Ventral primary rami.

Lumbar multifidus

Muscles originating on $L1-5$ spinous processes and laminae; they function to extend and stabilize the lumbar spine and neutralize flexion moments during trunk rotation.

Multifidus (cervical and thoracic)

Muscles originating on cervical and thoracic spinous processes that perform extension and contralateral rotation.

Quadratus Lumborum

A muscle originating from rib $12$ and $L1-L4$ transverse processes that fixes the last rib during inspiration, hikes the hip, and forms guy wire support to stabilize the lumbar spine in the frontal plane.

Iliocostalis thoracis

Muscle originating at the angle of the lower $6$ ribs and inserting at the angles of the upper $6$ ribs and the transverse process of $C7$.

Iliocostalis cervicis

Muscle originating at the angles of ribs $3-6$ and inserting at the transverse processes of $C4-C6$.

Longissimus cervicis

Muscle originating at the upper $4$ or $5$ thoracic transverse processes and inserting at the posterior tubercles of the transverse processes of $C2-C6$.

Longissimus capitis

Muscle originating at the lower $3$ or $4$ cervical articular processes and inserting at the mastoid process.

Spinalis (thoracic, cervicis, capitis)

Muscles providing extension and lateral flexion of the spine/head; it is noted as being well developed in the thoracic region ONLY.

Iliocostalis Lumborum

Muscle originating on $L1-L4$ transverse processes and the angles of ribs $5-12$; it performs back extension, side bending, and creates posterior shear forces to counteract anterior shear forces.

Longissimus Thoracis

Muscle originating on $L1-L5$ accessory processes and $T1-T12$ transverse processes/ribs $4-12$; it performs back extension and side bending, and creates posterior shear forces.

Lumbar intermuscular aponeurosis

Structure formed by the $L1-L4$ caudal tendons of the longissimus thoracis.