The iliocostalis lumborum is the lumbar portion of the iliocostalis, forming the most lateral column of the erector spinae in the lower back. It runs from the iliac crest to the lower rib angles, serving as a primary lateral stabiliser and extensor of the lumbar spine. Its large cross-sectional area in the lumbar region makes it the dominant erector spinae muscle at this level and a primary target of spinal manual therapy and exercise-based rehabilitation for low back pain.
| Origin | Iliac crest and thoracolumbar fascia |
|---|---|
| Insertion | Angles of ribs 6 through 12 |
| Nerve Supply | Posterior rami of spinal nerves T7 through L3 |
| Blood Supply | Posterior intercostal arteries; Lumbar arteries |
| Actions |
|
|---|
During lifting tasks it contracts powerfully to resist forward flexion of the lumbar spine, acting eccentrically during the lowering phase and concentrically during the return to upright, a loading pattern that explains its vulnerability to acute strain.
Iliocostalis lumborum strains are one of the most common acute low back pain mechanisms, produced by sudden unguarded lifting or trunk rotation. The muscle is assessed during the modified Biering-Sorensen test of prone trunk extension endurance, which has been shown to predict future low back pain episodes. Trigger points in the iliocostalis lumborum refer pain across the low back, into the buttock, and occasionally to the upper thigh.
Palpable as the most lateral band of the erector spinae mass immediately lateral to the longissimus, running parallel to the spinous processes in the lumbar region and becoming hard during resisted trunk extension.
Acute muscle tear from sudden unguarded lifting or rotation producing sharp unilateral low back pain with extension restriction, one of the most common presentations of acute mechanical back pain.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
