Low back pain causes: Lumbar paraspinal muscles

Back pain, Low back pain, Muscle information, Understanding pain / Wednesday, October 21st, 2009

This is a series on low back pain. If you missed the summary of causes, go back to Part 1.

Running all the way down your back are two sets of muscles, together called the erector spinae. They keep the spine erect. With the prevalence of postural issues at all age levels, these muscles are common causes of low back pain. The longissimus is nearest to the spine and the iliocostalis farther out on the ribs. They merge in the lumbar spine with the longissimus muscle fibers ending there (tendinous fibers continue to the sacrum) and the iliocostalis muscle fibers terminating on the sacrum with their tendons. They can work together in a unit or separately on parts of the spine a little like a snake.

Their action when working together is to straighten the spine and extend it backward. When working only on one side they do side bending (lateral flexion) and some rotation. They function as stabilizers, resisting gravity as you bend forward and sideward. (This is called a lengthening contraction.) At 90 degrees of forward flexion they are in maximum activity and the ligaments have been active since 45 degrees. For those of you in pain, note that coughing and straining with constipation causes vigorous activity of the erectors. Interestingly, when you are standing perfectly straight on your feet, your back completely relaxes! Another plug for good posture.

erectortrpsThe Trigger Points from the erector spinae that refer to the low back come from the lower segments. Pain is referred mostly into the buttock all the way from the top of the hip bone to the bottom crease.

Dysfunction in these postural muscles can cause joint dysfunction at the level where they are tight. Pressure in the joint fires off the nerves which produces pain. Functional (not structural) curves in the spine can cause contraction of the muscles on the convex side.

Conversely, scoliosis from genetic sources or from structural asymmetries is a huge factor in producing pain by contracting the back muscles unevenly. A longer leg or bigger hip bone usually contracts the muscles on that side.

Chronic muscle contraction (tension or tightness) can lead to the formation of Trigger Points. Active and latent Trigger Points can create satellite and secondary Trigger Points in their referral zones. See the progression … pain that feels like it’s spreading. Rather, it’s like a relay race. One TrP passes signals to another zone which in turn passes the signals on to the next zone. In healing these conditions, one of them called Myofascial Pain Syndrome, the last in the relay line is the easiest to correct. The first or originator of the pain will be most resistant to healing and take the longest time.

As a Neuromuscular Therapist working in Metro West Boston, I treat these muscles every day. The gluteus maximus and medius are related, directly across the hip bone from the erector spinae and directly connected by the lumbosacral fascia. That’s the next post.

5 Replies to “Low back pain causes: Lumbar paraspinal muscles”

  1. Six months after beginning a running regimen, I began having a pain in my right hip. I thought it might be greater trocanter bursitis, but after seeing a physician was told it was my paraspinous muscle. After months of doing exercises and having a decrease in pain I decided to try running again. One session resulted in significant pain for days afterwards. The pain progressed to the point where my entire lower back was experiencing discomfort. I have a spot deep in my right gluteal that is painful to pressure as well. I have begun seeing a massage therapist with a background in physical therapy and am hoping to eventually get back to my running. Is that even possible? I am 47. What else should I be doing?

    1. Hi Cathy, The paraspinals are a group of muscles, both superficial and deep, that are on either side of your spine. There are several. In your case, it sounds as if the impact of running may be compressing the L5/S1 joint at the base of your spine where you’ll find a thick pad of multifidi muscle. If that is tight it can compress the joint more and cause some pain. Or, the muscles may be cramping and causing local pain. Or, any of a few muscles may have developed Trigger Points that get active when you run. Deep muscle treatments, especially a Trigger Point therapy like Neuromuscular Therapy will help the most, along with a good home program of stretching combined with core strengthening at least twice a week with Pilates or an exercise ball. At some point, I would suggest finding another good cardio exercise to alternate with your running. Eventually aging takes it’s toll and we have to find ways of modifying or changing our favorite physical activities.
      Another thing is about that pain deep in your butt. That’s the piriformis muscle and could be at the heart of your problem. If you enter “piriformis” in the search box in the right side bar, I know I’ve written a few times about it. See if that gives you more insight.
      Lastly, check out the iliopsoas muscle in the search box. It’s a hip flexor, attaches to your lower spine and has Trigger Points that refer into the low back. it’s usually really significant in low back problems and has not been well known among medical people until recently.

  2. I’ve been dealing with reoccuring low back strain for some time. It goes and comes back most of the time from no strain or even weight lifting. I play golf and it doesn’t seem to effect it. I am grateful for this info and seems to contain items that are the cause of my back problems and will look into more exercises for these muscles.

  3. sir ,i want to know the best treatment of chronic left lumbar para-spinal trigger band.
    pain is continuously increasing since last 2.5 years.
    thank you .

    1. Sounds like you are out of balance from a structural asymmetry, old injury, or repetitive motion. Other than manual treatment of the muscles, your best maintenance would be Pilates and stretching to correct the imbalance and strengthen your core muscles. Do a search for Limbering the Low Back in my blog for a good morning routine to get your lumbar muscles ready to hold you up for the day.

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