Foundations Of Chiropractic (FOC) Exam 2 Practice

Intervertebral discs are the main load-sharing elements of a spinal motion segment, distributing axial compressive loads and allowing controlled motion. The nucleus pulposus behaves like a hydrostatic gel that spreads pressure through the annulus fibrosus, keeping vertebral endplates spaced and reducing peak stresses on bone and facet joints during bending and compression. In a healthy disc, this arrangement helps maintain normal spacing and mechanics across the motion segment. Degeneration undermines this function by reducing water content and proteoglycans, leading to desiccation and disc height loss. With less height and a less able nucleus to distribute load, more force is borne by the facet joints and posterior elements. This increases facet joint loading, promoting facet arthropathy and potential stenosis, and it also alters the segment’s stiffness and range of motion, often contributing to instability and nerve irritation. Discs do participate in load sharing, so saying they do not is incorrect. They are not calcium storage sites, which is a bone-focused role. And SAMPLEdegeneration affects more than nerve conduction; it changes how the spine carries load and moves.