As I grow in my Osteopathic journey, and really my life, it is interesting to note how many things are directly in front of us and easily accessible yet seemingly unused. One such case is the very basic anatomy of the spinal cord and the vertebral column. When looking back through posts I have made on this site I have always made specific use of the term vertebral column as I do not consider the spinal cord as synonymous with it and I definitely do not consider the term spinal column accurate or useful. As we go through this short journey I will make it clear why!
The spinal cord, in an adult (!) generally ends at the level of L2 (!). Yes I am bracketing those exclamation marks on purpose – to show common knowledge that is not being employed in a useful way or communicated in a useful way. If the spinal cord ends at L2 how in the blue heck can we have cord segments from L3-CO1??? Simple – the spinal cord segmentation does not match that of the vertebral column…hence the naming conventions get confusing as nerve roots are a topic of heavy discussion. I argue that the discussion should focus on the location of the spinal cord segments followed by the path they take to their terminal branches. I also argue that this was likely common practice for Dr. Still and his students as the level of anatomy they had was far more detailed than ANYONE on the planet has today mostly through specialization of surgeons on body parts or regions.
In reading Dr. Still as well as some other early Osteopaths it is becoming clear to me that the writing styles employed allowed for the loss of some information in translation (from thought to written word as well as from that English to this English and even from that time to this time). Osteopathic centers are not absolutely worth a lot in treatment or diagnosis as they are really just observations made on places that seemed to show dysfunction more often than not with certain conditions…and that is anecdotal evidence that when handed down biases lesion hunting and obscures the picture the patient on the table is really painting. I find it both helpful and lamentable that Dr. Still never specifically stated in writing (at least to my knowledge) to know where the spinal cord segmentation is and how that is different than the location of the vertebrae it sends nerves through. The lament is that that specific omission makes it confusing for some people and impossible for those to lazy not to do the work and learn to get that picture. The helpfulness is in the fact that for those willing to look they will be rewarded greatly and be further down the path to unwinding Osteopathic lesions as well as getting hit by the ram of reason pretty firmly and showing all of us that we have to look with open eyes and not just be guided by our expectations (maybe expectations as set by “Osteopathic centers”). I will say that Dr. Still was no fool and did nothing he did not mean to do – his sentiment was that Osteopathy was made by the intelligent for the intelligent (and if that sentiment did not belong to him then I will edit this and attribute it to someone else).
So back to the example of the sciatic nerve! The sciatic nerve ROOTS are generally accepted as L4-S3. So knowing the nerve roots gives us important information as to where the nerves leave the VERTEBRAL COLUMN to enter the soft portions of the soma. Now we need to dig a bit deeper and think about where the spinal cord segments live inside the vertebral column. The lumbar cord segments live in and around the bodies of T10-T12 while the sacral/coccygeal spinal cord segments live in and around the bodies of L1-L2. On a basic anatomical level that means the initial seat of the sciatic nerve COULD be as high as T10 (more likely T12). As a result of the real nerve root being in the bottom of the thoracic column we now have a real dilemma – the sacrum is now not the holder of the sciatic nerve, the sciatic nerve belongs to the thoraco-lumbar junction as well as the entire lumbar column. It is now no longer acceptable (at least if you read this or recognized this fact on your own) to look at the sacrum as the starting point for examination of sciatica. This piece of information also throws a lot of shade (in a negative way) on claiming that moving individual vertebral joints is likely to affect specific organs or areas as there is more information to consider as to the full path taken. This piece of information DOES GIVE CREDENCE to the idea of the utilization of accurate functional anatomy to aid natural processes though! If I know my business I now know that there is an important reason to make sure normal vertebral mechanics need to be present along the FULL path of the nerves and cord segments for any dysfunction.
Dr. Still did make specific, albeit veiled, reference to knowing the full path of a nerve with relation to the spinal cord segmentation. He made clear that anything controlled by segments within the thoracic spinal segments (or above) that one would treat generally from the OA to T8 (sometimes lower if called for) and that anything controlled from the lumbar segments and lower it would be important to treat from T8 down. Special attention need only be paid to those places found with dysfunction anywhere along the road the practitioner is taking. This has a lot to do with the location of the spinal cord segments and then the direction of the nerve paths from there to the target at the end of the line.
I do want to call special attention to the thoraco-lumbar junction as the central pivot and what that can do to all function below the diaphragm (ie digestion, excretion, and reproduction). The region has been termed the central pivot by Rob Johnston at the CAO for good anatomical reasons which I have probably written about many times before.Dysfunction of the central pivot or a dis-coordination between the shoulder girdle (upper baseline) and the pelvis (the lower baseline – really the line between the two hip joints) will alter on some level the signalling in the region of the central pivot and thus function below the diaphragm. Instead of getting too deep in to that conversation I will simply say spinal cord segmentation really matters!
If you know where the cord segments are then the art of treatment becomes much more colorful!