Muscle and Function: The Quadratus Lumborum
The Quadratus Lumborum (QL) is a deep core muscle located on both sides of the spine that connects the iliac crest to the 12th rib and lumbar spine. Its primary functions are to unilaterally flex the spine laterally and working together to extend the vertebral column. It also helps to anteriorly-tilt the pelvis.
This muscle is important (aren’t they all?) not so much for where it is or what it does, but rather what it ends up doing and the problems that occur when that happens. The QL is primarily an “assisting” muscle, meaning that of the listed functions, there are other muscles that perform the movement better.
For example, the erector spinae are the primary lumbar extensors in our bodies. When the erectors are compromised (i.e. weakened) because of a traumatic incident or excessive sitting, the QL has to help out. To provide stability, the QL are pretty much contracted for a long period of time (hypertonicity). Hypertonicity, over time, will cause muscles to spasm, eventually weaken and possibly form adhesions. All of this leads to low back pain! In this instance, the low back pain is caused by the QL, but the original culprit was a weakened erector group.
The same thing can happen when the hip abductors (gluteus medius and gluteus minimus) are weak. The abductors move the leg away from the midline of the body and stabilize the hips when walking. When the QL takes over for weakened abductors, the results are the “Frankenstein walk” and low back pain.
Keeping the QL strong (best exercise: side planks) is imperative. But what this really shows is that (1) you need to strength train on a regular basis and (2) your strength training program must address every muscle group to prevent imbalances.

About the author
Dwayne Wimmer founded Vertex Fitness Personal Training Studio in 2001, excited to bring a new concept about personal training to the people of Philadelphia’s Main Line in Pennsylvania. Driven by knowledge and results both, while a strength coach at Villanova University, he worked closely with world class athletes such as Brian Westbrook, formerly of the Philadelphia Eagles, on strength training and conditioning for optimal performance. Dwayne’s client base extends much further than world class athletes. Along with athletes, he works with adolescents to seniors, and he’s a highly acclaimed and sought out personal trainer who has received numerous awards, such as Best of the Main Line Personal Training Studio and Best Main Line Personal Trainer.
A graduate of Missouri Western State University, Dwayne has a Bachelor of Science degree in Physical Education, with an emphasis in Coaching. Aside from personal training, he’s spent time as a physical education teacher, strength and conditioning coach, and a football coach, but has found his passion and home in the fitness industry, inspiring and reaching out to others. As a strong believer in continuing to learn, Dwayne has also taken classes at East Stroudsburg University toward a Masters Degree in Sports Management.
He can add author to his list of accomplishments, having created a chapter in the upcoming book The Soul of Success with Jack Canfield, renowned for the Chicken Soup series.
To get to the point where he is now, Dwayne has always been thankful for the support of his father, a man who always believed in his mission and saw the need for what it was that Dwayne envisioned. During his free time, Dwayne is an avid motorcyclist who enjoys viewing the amazing landscapes and finding good restaurants to enjoy that are off the beaten path. He also takes advantage of opportunities to travel and experience many other cities while attending fitness seminars and giving presentations about the industry he is so passionate about. As a way to give back to the community that has been a part of his entire life, Dwayne has created Vertex Fitness PUMPED (People United Making Progress through Education and Donations), which provides support to area non-profits through a community-wide outreach effort. At this time, they help three non-profits per year in the Philadelphia area.
For more information from Dwayne, you may contact him at (610) 525-6604, dwayne@vertexfit.com