Since then, our profession has been conducting research to help determine why spinal manipulation or adjustments work so well.
Many conditions have been studied, as well as the physiological responses to the adjustment including blood chemistry changes including hormone levels, blood pressure changes, circulation changes, and many other parameters of health.
But the question remains: how important are spinal curves in the overall health picture of the patient? Can alterations in the “normal” curve lead to future trouble or, be the cause of a current condition?
A recent study reported the results after conducting a “systematic critical literature review” where all research published on this subject was reviewed for quality and content.
They gathered 54 studies published between 1942 and 2008, which included over 20,000 patients and reported the association between the sagittal curve (curves when looking at a person from the side) and various health conditions.
There were many different types of studies and methods used to evaluate the sagittal curves of the lumbar (low back) (38 studies), thoracic (mid back) (34 studies) and cervical (neck) (6 studies) spine.
These methods included plain x-ray (25 studies), MRI (1 study), photographs (3 studies) visual analysis or, by the eye (5 studies) and those using a variety of instruments (21 studies).
A strong association was reported in five studies with an increased angle in the midback/thoracic spine (kyphosis – sometimes referred to as “humpback”) with lung disorders causing breathing problems.
Poor physical function and pelvic organ prolapse were also strongly associated with kyphosis.
A moderate association was found when the low back curve (lordosis) was reduced, which was associated with an increase in low back pain.
Similarly, future osteoporotic midback/thoracic compression fractures were moderately associated with kyphosis or “humpback” deformity.
Kyphosis was also moderately associated with heavy household activity, uterine prolapsed and death in three other studies.
No association was found in many studies.
The conclusion of the article reports most of the studies did not fulfill the basic requirements for this type of study or had design flaws.
They encouraged researchers to use new/better approaches to study this association between spinal curves and health and disease.