Examine This Report about The Lumbar Spine - Joints - Ligaments - TeachMeAnatomy(See the image below.) Lumbar spinal muscles. Extensors The extensor muscles are organized in 3 layers. The biggest group of intrinsic back muscles and main extensor is the erector spinae (or sacrospinalis). In the lower L-spine, the erector spinae looks like a single muscle. At the upper back area, it divides into 3 vertical columns of muscles (iliocostalis, longissimus, spinalis).The iliocostalis is the most lateral, and the spinalis (smallest muscle) is the most median. The longissimus (biggest muscle) inserts on to the skull base, whereas the iliocostalis inserts onto the angles of the ribs and transverse processes of the lower cervical vertebrae. As these muscles rose up the vertebral column, they divide regionally depending on where the muscle attaches superiorly.In the sacrum, it originates from the laminar location simply medial to the posterior sacral foramina, from the tendinous origins on the erector spinae, and the medial surface of the posterior exceptional iliac spine (PSIS). Each fascicle is directed superomedially towards the inferior and median margin of the lamina and nearby spinous process.Nonsurgical management of lumbar spine stenosis: USASP guidelinesVertebrae in the Vertebral ColumnThe 20-Second Trick For Spine Structure & Function: Parts & Segments, Spine ProblemsThe transversospinal muscle group acts both as an L-spine extensor and a rotator. A plethora of little, segmental muscles are the inmost layer of the back extensors. Full Article can be divided into 2 groups, both innervated by the dorsal rami of spine nerves. The levatores costarum are not normally present in the back spine.The interspinales consists of short fasciculi connected in between the spinous processes of contiguous vertebrae. The intertransversarii consist of 2-3 slips of muscles, which pass in between nearby transverse procedures. They are postural stabilizers and increase the performance of bigger muscle group action. Forward flexors Flexors of the L-spine are divided into an iliothoracic (extrinsic) group and a femorospinal (intrinsic) group.The femorospinal group is comprised of the psoas significant and iliacus muscles. The psoas major originates from several areas: the anterior surface and lower border of transverse processes of L1-L5, from the bodies and discs of T12-L5. It inserts on to the lesser trochanter of the femur and is innervated by direct fibers of the back plexus (L1-L3).
