Vertebral Subluxation Complex (VSC)
This is a concept that can be made to be as complex or as simple as needed. In essence, 
VSC is a condition that exists when one or more vertebra fail to move and function in coordination to its adjacent vertebra that results in a depressed neurological function of the Central Nervous System.
Often this condition is explained as, “bone out of place”. Unfortunately, this is very misleading. Where as this can sometimes happen, it is very rare for a bone to literally be out of place. More often this condition is associated with a fixation of joint segments limiting or preventing the joint from freely moving in a coordinated manner with the rest of the spine. This condition can cause the spinal nerves to be stretched, twisted, or compressed; all of which cause significant depression of nerve function.