PT Classroom - Quadratus Lumborum and its Relationship to Low Back Pain  ׀ by Nicholas Brzozowski, SPT


The quadratus lumborum (QL) muscle is considered among practitioners who have learned to recognize its trigger points by examination to be the most frequent muscular cause of low back pain (LBP), but also one of the most commonly overlooked (6). Anatomically, the QL is considered a muscle of the posterior abdominal wall and acts as an extrinsic stabilizer of the trunk, with attachments inferiorly to the ilolumbar ligament and iliac crest and superiorly to the twelfth rib and the tops of the transverse processes of L1-L4 (4). Contracting bilaterally, the QL extends the lumbar spine (4). Contracting unilaterally, the QL acts as a lateral flexor of the lumbar region with minimal contribution to axial rotation (4). In addition, the QL fixes the 12th rib during movements of the thoracic cage during forced expiration also holds the twelfth rib inferiorly in inspiration, thereby allowing the thoracic cage to expand fully (2).

Functionally the QL positions the spine relative to the pelvis, and aids in maintaining an upright posture while coordinating with the erector spinae muscle group to create fine lateral movements and extension (2). Upon standing, the two QLs, in conjunction with the gluteus medius, position the upper body over the lower body (2), and the QL assists in the load sharing for spinal stability in the flexed trunk posture (1). While walking, the QL and gluteus medius aid in pelvic stabilization as the body weight shifts from one foot to the other (2); in addition, the QL lifts the iliac crest towards the thoracic cage as weight shifts to the other foot, which allows the leg to swing forward without the foot touching the ground, which is why the QL is often clinically referred to as a “hip hiker” (2, 4).

QL and its relationship to back pain
While there are many possible causes of back pain and discomfort, including a herniated or degenerated disc, nerve entrapment, muscle strain, etc., trigger points in the QL are commonly overlooked (6). Acutely, patients often report a persistent, deep, aching pain at rest, and can be excruciating in any body position, especially in the unsupported upright position and in sitting or standing that increases weight bearing or requires stabilization of the lumbar spine (6). Travell and Simons suggest that active trigger points in the QL can refer pain along the iliac crest and sometimes to the adjacent lower quadrant of the abdomen and into the groin, the greater trochanter and outer aspect of the upper thigh, the lower buttock, and strongly to the area of the SI joint (6). An original study by Iglesias-Gonzalez et al. (2013) found that active trigger points in the QL, iliocostalis lumborum, and gluteus medius muscles were the most prevalent in patients with chronic nonspecific LBP compared to a control group of healthy individuals, and a greater number of active trigger points was associated with higher intensity of each participant’s pain episode as well as worse sleep quality (3).

Over time, weakness in the lower fibers of the erector spinae muscles can cause the QL muscles to chronically contract bilaterally, and with impeding muscle fatigue, can result in an adaptive postural shift placing increased tension on the QL (2). This chronic contraction of the QL can cause the fascial sheath to transmit a strain through the rest of the back, even up into the neck and shoulder regions, and develop muscle spasm which forcefully contracts when it becomes hyper-excitable. (2).

Another problem with a tight QL is a condition that can develop during the swing phase in gait, previously mentioned as “hip hiking” (2). With this condition, a weak gluteus medius and/or minimus can force the QL and tensor fasciae latae to act as compensatory prime movers of hip abduction, thus resulting in excessive lateral compression of the lumbar segments of the spine (2). In a meta-analysis by Sadler et al. (2017), restriction in lateral flexion and hamstring ROM, as well as reduced lumbar lordosis were associated with an increased risk of developing LBP over a 12 month period (5). Due to the QL having very favorable leverage as a lateral flexor of the lumbar region (4), it is particularly interesting that a restriction in lateral trunk flexion might be a predictor of LBP. There were three studies that assessed lateral flexion specifically and involved 1,364 total participants (5). These studies revealed a significant association between reduced lateral flexion ROM, measured by the distance that participants could slide their hand down their ipsilateral thigh, and the development of LBP (OR=0.41, 95% CI 0.24-0.73, p=0.002) with a low and non-significant amount of heterogeneity present (I2 =15.9%, p=0.304) (5). Alternatively, this can be expressed as an OR of 2.44 (1/0.41) which means that those participants with limited lateral flexion ROM have a 144% greater likelihood of developing LBP (5).

While LBP can present in a variety of different manners and involve a several different structures, it is important not to overlook the role that the QL can play in both acute and chronic LBP cases. Of course, a comprehensive approach to back pain is always recommended, but some common strategies to treat an involved QL include assessing and correcting postural imbalances and compensations such as a functional lumbar scoliosis or lower limb length inequality, stretching and strengthening exercises to stabilize the pelvis, and soft tissue mobilizing techniques including friction massage, myofascial release, acupressure, and trigger point dry needling to target restricted connective tissue (2, 6).


Last revised: August 28, 2017
by Nicholas Brzozowski, SPT

) Colloca CJ, & Hinrichs RN. The biomechanical and clinical significance of the lumbar erector spinae flexion-relaxation phenomenon: a review of literature. Journal of Manipulative and Physiological Therapeutics. 2005. doi:10.1016/j.jmpt.2005.08.005
2) De Permentir P. Quadratus lumborum: anatomy, physiology and involvement in back pain. Journal of the Australian Traditional Medicine. 2015;21(4):241-242.
3) Iglesias-Gonzalez JJ, Munoz-Garcia MT, Rogrigues-de-Souza DP, Alburquerque-Sendin F, & Fernandez-de-las-Penas C. Myofascial trigger points, pain, disability, and sleep quality in patients with chronic nonspecific low back pain. Pain Medicine. 2013; 14:1964-1970.
4) Neumann D. Knee. In: Neumann D. Kinesiology of the musculoskeletal system: foundations for rehabilitation. 2nd ed. St. Louis, MO: Mosby; 2010
5) Sadler SG, Spink MJ, Ho A, De Jonge XJ, & Chuter VH. Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies. BMC Musculoskeletal Disorders. 2017;18:179. doi:10.1186/s12891-017-1534-0.
6) Travell JG & Simons DG. In: Myofascial pain and dysfunction the trigger point manual: the lower extremities. Vol 2. Philadelphia, PA: Lippincott Williams & Wilkins, 1993.

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