The Sacrum
The Foundation Stone
By: Dr Bruce Vaughan, DC

Knowledge is power.
Sir Francis Bacon

One of the most abused and overlooked bones in the human body is the SACRUM; that heart shaped bone that we sit on. For the last half of the 20th century medical specialists had been saying that there is no movement between the SACRUM and the two ILIA that make up the PELVIS. Their argument was based on the massive interosseous ligaments that bind the SACRO-ILIAC (S/I) articulations.

Both the Chiropractic and Osteopathic professions have recognized that there was movement, albeit subtle, and that pain can result when that movement is impaired. Various researchers have been able to monitor and document movement in the S/I joint, but there was some confusion as each researcher reported a different axis of movement.

There really should be no confusion as the S/I has many functions and requires a different type of movement for each and thereby a different axis of movement — the movement between different parts of the pelvis whilst walking are different from the motion required when sitting, standing or bending forwards or backwards.

The particular shape of the surfaces of the SACRUM appears, at first glance, to be rather crude, but they are in fact a miracle of engineering design. The S/I joint has two main functions. First, to give weight-bearing support to the torso above and transfer that to the legs below whilst allowing for subtle movements — I emphasize subtle movements because the amount of movement is almost immeasurable, requiring very precise instruments to exhibit.  The second important function has to do with the movement of the fluid within the spine and cranium called the Cerebrospinal fluid (CSF).

Since it plays such a vital role in nearly all postural and movement dynamics, impairment within the S/I joint can result in pain that can be extreme. It can also be responsible for pains throughout the spine and into the legs (knees and ankles have to adapt to the change).

The well-being and stability of the S/I joint can be easily assessed by a qualified chiropractor and correction made. Once corrected, care has to be taken for the first few weeks to allow for healing. People who have had a long standing S/I problem should check with their chiropractor from time to time to make sure that it is still strong. A check up once or twice a year would be sufficient.     

Dr Bruce Vaughan and Dr Jeff Shurr are practicing chiropractors at Drs B.S. Vaughan & Associates located in Central. (HK’s longest practicing chiropractor centre)