Low back pain causes: Repetitive stress


Back pain, Chronic pain, Low back pain, Muscle information, Pain relief, Repetitive strain, Understanding pain / Sunday, October 11th, 2009

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

When we move, our muscles work by contracting and relaxing, shortening then lengthening. Muscles work in opposing pairs. As one muscle contracts, the opposite muscles relax. That’s how we get movement. For instance, if the biceps contract to bend the arm at the elbow, the triceps must lengthen. If they both contract at the same time movement stops. That happens either for stability or because of diseases such as cerebral palsy. Every time a muscle contracts the blood flow is reduced by about 20%. When it relaxes, blood flows normally. Contracting and relaxing pumps blood in and waste out, keeping the muscles healthy and happily working for you.

Another thing that’s important to understand about muscles is that every time they do work they burn metabolic fuel. Every time you burn fuel you get a waste product. The metabolic waste goes into the fluids around the muscles. If the muscles are constantly contracted, the waste can’t get out, so it gets stored in the tissue as acids (like lactic acid). With repetitive use, the waste products build up and the blood can’t deliver enough nutrients and oxygen to the muscles to keep them healthy. Both cause toxic conditions and pain. Over time and with repetitive use the cells of the tissue involved become unhealthy, both because it can’t heal without getting enough blood and because the cells begin to break down in the toxic acidic environment in which they are trying to live.

In order to get rid of the pain and rebuild healthy muscles, it is essential to get blood flowing efficiently through them. Stretching lengthens them and allows more blood through. Stimulation like short applications of ice or heat increases blood and lymph flow in the capillary beds under the skin. Giving the muscles some time off reduces stress. Add some deep belly breathing. Relaxation has it’s place.

A third thing to remember about muscles is that when one muscle or group of muscles is chronically tight, the muscles that oppose them will be weak. That means that other muscles have to compensate and the imbalance produced causes joint problems. When low back muscles are chronically tight from repetitive stress, the abdominal muscles get weak. That imbalance puts a strain on the vertebral joints, tightening the muscles that move them, straining the ligaments that hold them together and compressing the discs and nerves between them. To fix this, strengthen the core, lengthen the back muscles and move the muscles that don’t get used enough (think twisting, side bending and oblique abdominal movements).

At my Neuromuscular Therapy center near Boston, we have Pilates lessons and classes to encourage core strengthening and build muscle balance. You can also reference the Limbering the Low Back exercise sheet we give to low back pain patients to tone the core mucles.

One Reply to “Low back pain causes: Repetitive stress”

  1. Ms. Abbot, congratulations on a simple, well-written series on the causes of back pain. Like anything in life, there’s a lot of gray area (as opposed to black and white) when it comes to the causes of back pain – this is something I’ve learned (sometimes the hard way) over the course of 20 years of caring for my injured back. Your explanation of the complex, often-interconnected factors behind back pain will help those in pain to develop a good basis for understanding often-complex diagnoses – giving them powerful knowledge about what they can do to effectively manage their pain by understanding where it’s coming from. Thank you!

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