Causes Of Low Back Pain: Does Weight Matter?

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Often I am asked whether being overweight is one of the causes of low back pain.

Maureen Dwight

As a health professional it’s easy to say yes when confronted by a protruding belly or a heavy set body however the connection with low back pain is not as direct as we might expect.

When it comes to low back pain, recommendations for weight loss are almost as common as being told to strengthen your core,[1] however there is insufficient science to support this perspective. Having gone through a severe episode of sciatica most people are ready to commit to almost anything to not have this happen again.

Although I would endorse weight loss for a variety of reasons, if your goal is addressing the causes of low back pain my perspective is that it doesn’t really matter what you weigh.  What is key is having the strength to carry it. In my practice I have clients weighing 95 lb.who are suffering with back pain.  I also have clients weighing 300 lb. who are fully recovered.  The question I find more telling is whether you have gained weight recently and/or started on an intense new fitness program.  Answering yes to one or both of these questions provides me with more insight into the cause of your low back pain than simply calculating your body mass index[2].

Weight gain, sedentary lifestyle and intense exercise are causes of low back pain

A common history bringing you into my practice begins with a resolution to finally lose the 20+ lb. put on over the last 2-3 years.  Dieting is difficult, so often fitness becomes the method of choice.  Running, boot camp or cross fit seem to offer the most promise to kick start the loss.  Even if you have not exercised recently, many commit to 5-7 days per week.

The first few workouts go okay and then one day you wake up sore.  Your low back is aching.  From there it is downhill.  Within a few days the pain intensifies.  It starts to shoot down your leg.  Suffering from full blown sciatica erases any possibility of exercise and starts the perfect storm.  You begin to gain weight as not only can you not exercise, you now can barely walk.  Comfort food adds to the problem and instead of being 20 lb. overweight you are on you way to 30+.

Based on a study by Dr. Cholewicki[3], we know that even a modest increase in weight, particularly when gained quickly is sufficient to predict low back pain in athletes.  In this research study he followed Varsity level athletes, proving that every 1 kg. increase in weight, gained over a 3 year period increased the risk for low back pain by 3%.   Although I might quibble with his definition that 2.2 lb. gained within 3 years is rapid, I cannot disagree with the outcome. Recent weight gain compounded by an excessively intensive exercise program are key causes of low back pain.

Rapid Weight Gain is one of the Causes of Low Back Pain

Why a rapid increase in weight is more problematic than just being overweight can be best explained by how we build strength in the first place.

As children our body adjusts to weight gain by building both the muscle and the coordination[4] to heft this additional bulk around. As adults, changes in our body weight also needs to be paralleled with increases in both of these factors.

Based on Cholewicki’s study, even in highly trained athletes it takes time to make the needed adjustments to accommodate changes in body mass. Preventing injury requires enough strength for our body weight and the demands of our lifestyle

The second factor, excessive intensity of the fitness program, can compound the issue.  The longer we spend developing our careers, raising our kids and ignoring our bodies, the greater our deconditioning[5] and loss of muscle strength.  When you couple deconditioning with an additional 20 lbs. of body weight, engaging in a high-intensity fitness program can feel like 30 to 40 lb. to these mid-life weakened muscles.

Getting out of the vicious cycle

Once this vicious cycle of weight gain and inactivity sets in I find it takes a lot more effort to get on track than preventing issues in the first place.

Selecting a more modest exercise program combined with good eating habits would likely have given you the success you were looking for but now we need to start much slower.  The presence of sciatica and back pain predicts that the initial imbalances in your strength to weight ratio are now worse.  Instead of only battling weight gain and deconditioning, you now have post-injury compensatory patterning.  All three factors must be taken into account when planning your therapy program.

At this stage in your recovery I recommend seeing an experienced spine therapist who recognizes that pinched nerves complicate your return to exercise. Once there is involvement of the nerves (sciatica), these types of injury predict that some muscles will be weaker than others.   A failure to recognize and specifically target these imbalances is one of the key factors I find limiting your recovery.  It can often be the primary cause of pain whenever you try to get more active.  These compensatory patterns[6] need to be addressed before a general exercise program or returning to the activities you love becomes possible.

Compensatory patterns must be addressed before returning to a more active lifestyle

In our clinic we have learned to anticipate these patterns and address the changes as soon as they start to emerge. This is ideal, however even when that early opportunity has been missed, the chance for improvement is still good as most people can learn to restore these movement patterns even years after the initial injury.

The next topic:  How balance strategies cause low back pain. 

[1] https://orthophysio.com/news/physiotherapy/low-back-pain-and-core-strength/

[2] Height to weight ratio – BMI calculator app:  http://bmicalculator.cc/?gclid=CjwKEAjw8bO3BRDp0bP_vL-7_lASJACL_d6wfhlHKIor4Mtgm3rgaOB0xJwZphBhYKVzmPmPObWpSBoCrI3w_wcB

[3] http://www.ncbi.nlm.nih.gov/pubmed/?term=cholewicki+delayed+muscle+reflex

[4] This relationship is explored in the previous article on low back pain and core

[5] Loss of fitness

[6] Compensatory patterns and nerve involvement will be the subject of an upcoming blog.

This service pro­vides gen­eral infor­ma­tion and dis­cus­sion about therapy, health and related sub­jects. It is not meant to replace advice and/or treatment from your health care professional.