This state of affairs is currently under change, largely as a result of strong clinical trial evidence that spinal manipulation has specific effects on pain perception and joint kinematics. Although spinal manipulation clearly seems to influence patient outcomes, the biological mechanisms by which this occurs remain obscure. This presentation will focus on current research on the subluxation concept to include physiological definitions, clinical definitions, results from laboratory research, and results from the clinical world. Pain originating from these two functional segments also differs, as does the pathomechanics of the resultant pain. The atlas only significantly rotates upon the axis with slight flexion-extension.
Restriction is exerted by ligamentous structures.
There are no discs between the occiput and axis-atlas as occurs in the lower segments, and there are no foramena and posterior zygoapophysial joints. The search for anatomic pathology by increasingly sophisticated imaging techniques has failed to explain symptoms in more than a small percentage of patients with back pain. This has resulted in an increased interest in measuring various physiologic and biomechanical functions in the hope that abnormalities may be detected, which are associated with back pain and which may be amenable to treatment. However, it is now evident that most anatomical variations and many types of pathology, including degenerative disc disease and disc herniation, exist without detectable symptoms or loss of function. It is becoming obvious that it is the presence of functional changes that make pathology clinically significant and not necessarily pathology which causes abnormal function.