Muscle Strains Part 1: The Quadratus Lumborum (QL)
Certain muscles in the body are prone to strains. A strain can be extremely painful and can seem like a bigger deal than it is depending on the severity. Even a type 1 microtraumatic strain can leave you feeling like you cannot move. One particular muscle in your lower back, the quadratus lumborum or QL for short, can make you think you need an MRI. All too often, I hear of someone deadlifting too much with bad technique, and next thing they know, they can’t move. Off they head to get an image and low and behold, they have bulged discs. Hopefully they are sent to physical therapy first before there are any drastic interventions. I have seen some patients that go right to surgery to clean out the disc with no change in symptoms, because all the while, it was just a strained QL.
So how does a strain occur? They are caused by a strong eccentric contraction of a muscle,. Eccentrics are the negative phase of a movement. So picture doing a heavy barbell curl, and slowly lowering to the start position. This is the negative phase, or eccentric phase.
Eccentrics are a great way to rehab and build muscles, but we run into injury when they are forcefully and rapidly undergoing an eccentric contraction. Muscles have the ability to move joints, but they also have the ability to hold joints together, protectively. The myotatic reflex senses rapid elongation of the muscle and responds by contracting the muscle to keep the joint together. If the load applied to the muscle outweighs the capacity of the muscle, a strain occurs. In other words, a weak muscle is more susceptible to strain. This is why the 40 year old couch potato who decides to suddenly start playing basketball on the weekends without prior strengthening, ruptures an Achilles tendon when landing after a jump (eccentric phase of the calf).
Let’s return to the QL. It’s about the size of a filet of fish and attaches from the crest of the pelvis, to the lumbar vertebrae, and to the last rib. It’s function is to hike the hip, or if your feet are planted, it side bends your spine. So that exercise where you grab a dumbbell and side bend to one side is working your QL, not your obliques (it’s not going to get rid of the love handles). If you contract both QLs at the same time, it causes the spine to move into extension, so in other words they are on when you are standing erect. Postural muscles such as the QL that are working all day are susceptible to tightness (and therefore strain) because of the fact that they are on all day. You can contribute to this tightness by holding the muscle in sidebending or extension. Sleeping on your stomach will cause spinal extension and tighten the QL. Sleeping on one side will cause one-sided tightness. Keeping a George Constanza sized wallet in one of your back pockets while driving will definitely tighten one side.
There are sports that bias the QL such as golf (see the follow through), and hurdling. Any sport where you are in a position where you are crouched, such as hockey, will cause the QL to overwork because they have to work against gravity to keep you from falling forward. It is hard to avoid QL overuse.
Perhaps one of the largest contributors to a tight QL is weak gluteus musculature. In the frontal plane, gluteus medius lifts the leg on the pelvis. If it is weak, the QL can kick in and hike the hip in effort to lift the leg. It has a similar relationship with gluteus maximus in the saggital plane and can compensate for gluteus maximus weakness by arching or extending the spine.
Let’s add this all up. We have an already overworked muscle which compensates for weak hip musculature. Perhaps there is tightness superimposed from some sort of daily habit like a wallet in the back pocket, and maybe a bad sleeping position. Then you get hit while playing hockey and your back rapidly moves into extension or sidebending, or worse yet, both. The muscle responds protectively by violently contracting. It’s the perfect storm. It does its job of keeping you together, but you are left with pain. This is basically the same mechanism of a whiplash injury.
If you have numbness and tingling or pain shooting down your leg, perhaps you should see a physician to determine if you herniated a disc. If not, see a physical therapist for an evaluation. Chances are, it’s a QL strain. Physical therapy is effective in decreasing the pain, and when the time is right, teaching you how to stretch and relax the muscle.