So, What is the Lower Back Designed to Do?

By: Andrew Gorecki

So what is the lower back designed to do and why do so many people suffer with lower back pain?  Let’s talk first about how the lumbar spine is designed with the hopes that this will help answer the question of why so many people suffer.  First we must understand that every joint in the body has a limit to its movement.  We must also understand that the lumbar spine is designed to move in three planes of motion. So looking first at rotation from right to left we know that the lumbar spine biomechanically only has 5 degrees of rotation to the right and left.  Side to side motion the lumbar spine only has 30 degrees to the right and left.  Finally forward and backward bending the lumbar spine has roughly 60 degrees of motion available.

So when you think about it our normal daily movements include all of these motions and usually in larger degrees than the lumbar spine is designed to move. That means that other parts of the body must contribute to the movements of rotation, side to side, and forward and backward bending.  This is why I spend so much time speaking about how the feet, hips and upper back contribute to lower back issues.  Let’s spend a few minutes talking about the hips.  The hip joint is a large ball and socket joint that is also designed to move in three planes of motion with much more motion available than the lumbar spine . With rotation specifically the hip joint is designed to rotated 80 degrees.  Now image a golfer who is taking his swings.  If we were to take away motion in the hips the golfer would then have to have motion coming from other parts of the body to compensate for the lack of hip motion.  The first place that’s going to occur is in the lumbar spine. But remember earlier we said the lumbar spine is only designed to rotate 5 degrees.  So it only has 5 degrees to give and if it is asked to give too much it will damage itself.

Another example might be in someone who is raking their leaves.  During this motion there is mainly arm motions moving the rake.  This arm motion creates motion that transmits through the upper spine usually in all three planes of motion.  If the upper spine is tight, which is very, very common in our population, than the motion will not occur in the upper spine and it will be transmitted to the lumbar spine which has only so many degrees to give.

There are many more examples where other parts of the body are limited in mobility or stability and this contributes to increase stress in the lumbar spine.  It is important to understand that you must seek out the true dysfunction in order to fix the symptom of lower back pain.  99% of the time it is not the lower backs fault.