Quadratus Lumborum
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Introduction[edit | edit source]
The Quadratus Lumborum (QL) is the deepest back muscle and originates from the iliac crest and inserts on the transverse process of lumbar one through five and the lower part of the twelfth rib. Innervation of the QL is via the twelfth thoracic nerve and the spinal rami of the lumbar nerves.
The QL muscle is flattened and has a quadrangular shape; along with the multifidus and erector spinae muscles, the QL helps to create an antagonist force compared to the muscles of the abdomen.
The QL muscle is an integral part of the thoracolumbar fascia, a myofascial system that covers the posterior area of the human body, involving part of the lower and upper limbs.
Anatomy[edit | edit source]
Origin[edit | edit source]
Iliolumbar ligament and internal lip of Posterior iliac Crest.[1][2]
Insertion[edit | edit source]
Medial half of lower border of 12th rib and tips of transverse processes of lumbar vertebrae.[1][2]
Nerve Supply[edit | edit source]
- Subcostal nerve (T12)[1]
- Iliohypogastric and Ilioinguinal nerve (both from L1)[1]
- Branches from the ventral rami (L2 and L3)[1]
Function[edit | edit source]
The anatomy texts describe the quadratus lumborum muscle as an extensor of the lumbar spine, a stabilizer of the lumbar area, capable of tilting laterally and capable of acting as an inspiratory accessory muscle.
However findings show
- During extension, the QL exerts a force of 10 N, compared to 100 N and 150 N of the erector spinae muscles and the multifidus. It seems unlikely that it can extend the lumbar area on a sagittal plane with such a small force (10 N).
- The QL during a lateral tilt of the trunk it participates with less than 10% of the force required for a coronal inclination.
It seems likely that QL could act as a crossroad of the forces exerted by the neighboring muscles, influencing the vectors of the different tensions produced, thanks to its :strategic position; disorganised scheme of its fibers; and its function in the myofascial system.
Classic actions given below.
Actions[edit | edit source]
- Quadratus Lumborum fixes the 12th rib to stabilize diaphragm attachments during inspiration[3]
- Lateral flexes the vertebral column[3]
- Extends lumbar vertebrae[3]
- It forms with the contralateral Tensor fascia lata and Gluteus medius a lateral myofascial sling which aims to maintain frontal plane stability of the pelvis.[4][5][6]
Physiotherapy Implications[edit | edit source]
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The muscle group is considered a postural muscle group. QL is also part of the Core muscle. The core is the group of trunk and hip muscles that surround the spine, abdominal viscera and hip. Core muscles are essential for proper load balance within the spine, pelvis, and kinetic chain. They spare the spine from excessive load and are essential for lad transfer between the upper and lower body.
Quadratus lumborum is a continuation of transverse abdominal muscle. The transverse abdominal muscle is part of the anterior fascial system of the body. The transversalis fascia penetrates the abdominal musculature. It's one of the muscles that tends to be tight and overactive[7] In this situation it negatively influence the resting tension of the QL, altering the distribution of the lumbar area loads.
QL can cause low back pain with the emergence of a heterotopic ossification or myositis ossificans. The latter may result from direct trauma and inadequate healing.
It is difficult for a single muscle to cause pain, except with direct trauma. All the muscles interconnect as a function of the fascial system, and in a contractile area with altered function, it will lead to functional difficulty in all the surrounding muscular regions.
Trigger points can involve the QL. This condition could also mimic a painful syndrome of the lumbar area. Trigger Point Referral Pattern
Effects of tight/overloaded QL: Pain, pelvic lateral tilt limiting reaching and restricting breathing, if the QL is tight on both sides, lumbar lordosis increasing compression on spine.
For more see Quadratus Lumborum Syndrome
Dysfunction of the lumbar structures whether degenerative, neuropathy, and/or inflammatory, may contribute to poor muscle firing and weak stabilization by the QL.[8]
Lumbar spine pathologies like bulging discs, and facet joint hypertrophy from chronic inflammation may effect nerve conduction and response to the QL and Iliopsoas resulting in poor muscle stabilisation and mechanical stress from chronic contracture.[8]
Moaratty-Koehler Syndrome (MKS) is another condition related to QL dysfunction.
References[edit | edit source]
References will automatically be added here, see adding references tutorial.
- ↑ 1.0 1.1 1.2 1.3 1.4 Anatomy expert. 3D - Quadratus lumborum. Available from: http://www.anatomyexpert.com/app/structure/5307/ (accessed from 19 April 2019)
- ↑ 2.0 2.1 Keith L. , Anne M. R . Clinically Oriented Anatomy 7th edition. philidephia : Lippincott Williams & Wilkins.2017
- ↑ 3.0 3.1 3.2 Radiopaedia. Quadratus lumborum. Available from: http://radiopaedia.org/articles/quadratus-lumborum (accessed 15 August 2015)
- ↑ Morgan J. Modern Principles of Core Training. Lulu.com, 2010
- ↑ McCall P. Cutting Edge: Training the Fascial Network (Part 2). Sign.;888:825-3636.
- ↑ Wallden, M. (2014). The middle crossed syndrome – New insights into core function. Journal of Bodywork and Movement Therapies, 18(4), 616–620. doi:10.1016/j.jbmt.2014.09.002
- ↑ Page .P, Frank C, Lardner R. Assessment and Treatment of Muscle Imbalance: The Janda Approach .Champaign . Human Kinetics. 2010.
- ↑ 8.0 8.1 Acupuncture Integrated. Low Back and Lower Body Myofascial Pain Syndromes. Available from: http://www.acupunctureintegrated.com/articles/low-back-and-lower-body-myofascial-pain-syndromes [accessed 19 April 2019].
