There are several sources of low back pain. 

To understand the symptoms of low back pain, we must be aware of all the anatomical structures and how they contribute to the movement of the spine.  These sources can be grouped into our “mechanical” sources of low back pain (LBP). 
There are other sources of LBP that tend to be secondary to another condition that we will also briefly discuss.  We will refer to this second group as “non-mechanical” sources. 

Mechanical Sources of Low Back Pain

When we consider the mechanical sources of LBP, we are essentially identifying all the anatomical structures of the spine and matching the symptoms or mode of onset to the possible structures involved. 

  

As you can see, there are several structures in the spine that could potentially become injured.  The picture on the left shows the 4 segments of the lumbar spine as they would appear stacked in the spine. 

The picture on the right is a view of a cervical vertebrae looking from the top down with the bottom of the picture as the front of the body.  In this picture, you can see a partial disc and the bone underneath that it sits on, as well as the spinal cord with the nerve roots emerging from the cord.  Take note of all the blood vessels that are found in this area. 

Pain Assessment

During assessment, which is done to reproduce the patients’ pain, we can identify and even rule out sources of pain.  For example, when we have the patient turn to the side and bend backwards, we will stress the joints of the spine. 

What we are doing with this motion is bringing the two segments of the joint together into compression.  The joints are very sensitive, and this motion will elicit pain when this is the location of the injury. 

When there is a disc injury, there will be some degree of inflammation.  As you can see from the above diagram on the right, there is not a whole lot of extra space to accommodate inflammation or swelling. 

The yellow nerves above are very sensitive to pressure changes.  As inflammation accumulates with even a minor disc injury, the patient will experience the sensation of pain.  The amount of compression on the nerve will be depicted in the symptoms the patient presents  with ranging from local pain to numbness, tingling and/or weakness in either the arm, leg or thorax depending on the level of the spine involved. 

When healthcare practitioners are considering the source of the pain, we are considering the potential for any of the above structures (bone, ligaments, joints, disc, nerve roots, spinal cord, or vascular structures) as being the source. 

What is not shown in either of these pictures are all the muscles that attach to various parts of the bone.  The muscle can be a very large component of the patient’s pain. 

Determining the Source of Injury

Now, once we have determine the structures involved and they are mechanical, there can be many ways that these structures could have been injured.  Obviously, one particular instance of lifting or twisting can be the mode (or method) of injury.  But sometimes, there is not just one particular instance that produces the injury, but a prolonged, sustained bad posture may result in your back structures failing during their mechanical work resulting in an injury.  When this is the case, your assessment will address these structural changes to help develop a plan to avoid injury in the future.  

Non-Mechanical Sources of Low Back Pain

We must also consider the potential for non-mechanical sources of pain.  After taking a thorough history, the healthcare practitioner will have a good understanding as to whether or not the source of the pain is mechanical or not. 

Sources of non-mechanical spinal pain typically include pathologies in either spinal tissue or organs elsewhere in the body that refer to regions of the low back.  For example, a kidney infection can present as low back pain.  Gastrointestinal, uterine, bladder, prostate, lymphatic and pancreas disorders can also be non-mechanical sources to name a few. 

Treatment

The majority of LBP has a mechanical source.  Treatment may vary again based on the exact structure that is involved, i.e. disc injury vs joint injury.  If you are experiencing LBP, please see a healthcare practitioner who can differentiate the source of pain and provide you with the appropriate treatment. 

Please take advantage of our online booking and book your low back assessment with Dr. Marnie Mabee D’Andrea.