Quadratus lumborum, means “the square muscle in the low back.” It connects the lumbar vertebrae to the ribs and iliac crest trapping T12 and the sacrum its attachments.
Quadratus Lumborum has 3 sections; iliolumbar, lumbocostal and lateral. They perform different functions, have different trigger point patterns and are best addressed as different muscles.
Quadratus lumborum varies dramatically in dissection studies. The size, as well as the shape of each belly, have statistically significant variations. The muscle appears the be thinner medially with a thicker lateral belly in most cases. The quadratus shown in most illustrations, like this one, depict a healthy decompression of the low back. In mature adults, the lumbar vertebrae and lumbocostal space are usually compressed.
Electromyographical show that it is active in several functions; lateral flexion of the trunk, elevation of the hip, extension of the lumbar spine, forced exhalation, trunk rotation, brisk walking.
It is worth noting that the iliolumbar ligament develops from the immature fibers of the quadratus lumborum during the adolescent years and atrophies when the sacroiliac joint fuses in the 4th or 5th decade.
The iliolumbar section connects the crest of the ilium to L1-L4 trapping the sacrum and L5 between them. It is located posteriorly to the other sections.
The lumbocostal section connects the transverse processes of all the lumbar vertebrae to the medial half of the 12th rib, trapping T12 in between. It is the most anterior section.
The lateral section connects the central portion of the 12th rib to the iliac crest trapping the sacrum and T12-L5 between them.
The Framework of Therapy Course
This post leads you through a 75-minute presentation on building a winning bodywork session. It has many examples from the therapy room. It also takes you through the session framework and treatment plan for the classic seizing hamstring.
Please watch and fill out an evaluation. Your feedback is needed. We plan to start offering courses on Integrative Bodywork and Craniosacral in the spring!
Support Integrative Works to
and produce great content.
You can subscribe to our community on Patreon. You will get links to free content and access to exclusive content not seen on this site. In addition, we will be posting anatomy illustrations, treatment notes, and sections from our manuals not found on this site. Thank you so much for being so supportive.
Tony Preston has a practice in Atlanta, Georgia, where he sees clients. He has written materials and instructed classes since the mid-90s. This includes anatomy, trigger points, cranial, and neuromuscular.
Question? Comment? Typo?
*This site is undergoing significant changes. We are reformatting and expanding the posts to make them easier to read. The result will also be more accessible and include more patterns with better self-care. Meanwhile, there may be formatting, content presentation, and readability inconsistencies. Until we get older posts updated, please excuse our mess.