Low Back Pain. Leg Length Difference and Pelvic Rotations – It’s Snake Oil!
Leg length difference associated with low back pain is an exceedingly common osteopathic and chiropractic diagnosis. If you have a shorter leg on one side the pelvis will be rotated forward on that side. This is simple biomechanics. It’s like saying if you deflate the tyres on one side of a car the car will be rotated down by a few cm on that side. That is true, however, it does not make sense to link this biomechanical pattern with low back pain, in fact you would probably be more correct to say that leg length difference is normal and leg length equality is unusual.
Claiming leg length inequality is the root cause of a low back pain diagnosis is Snake Oil. There are millions of normal people and even high and elite level athletes with leg length differences and no back or hip pain but still many patients come to me after having seen other osteopaths or chiropractors and tell me their back pain is caused by their leg length inequality.
I often wonder then, if we are going to insist on claiming the asymmetry of a leg length is relevant perhaps, we should look at all the asymmetries in the body. For example, most of us accept we have a leg that is significantly stronger than the other, but rarely do we consider that a problem. Or we all have a heavy liver which occupies a good chunk of the right side of our thoracic cavity compared to the left where the lung has an extra lobe (ie it’s basically full of air.) But, in all my years in practice nobody has ever seriously asked me about the biomechanical asymmetries associated with weight imbalance in the thorax.
Sure, I will concede that a simple heel raise placed in the shoe to equalise the leg lengths can give a quick, cheap reduction of low back pain in many instances. But this is a false win, not a long-term solution. It should only be done where short-term pain relief is required whilst the more serious work of making the body stronger and more resilient is done. Ask the question: Why is my low back so sensitive that I cannot tolerate a normal leg length difference like almost everybody else has? Once the body is more resilient it will cope with a normal leg length asymmetry, no problem at all.
PS Nobody has ever clicked a rotated pelvis caused, by a leg length difference (or any other cause), back into place on an osteopathic or chiropractic table. I’m not saying you can’t get symptom relief without clicking, because you can but, it’s not because a joint has been realigned. This is a whole different smoke and mirrors show that I will talk about on another day.
In the meantime, if you have low back pain and a leg length difference of less than 4cm the long-term answer to your pain is not correcting the asymmetry with a heel raise or a couple of clicks.