Low back pain can arise from a variety of structures in the lower back. When symptoms include pain, tingling, numbness, and/or burning that radiates into the buttock, thigh, calf, or foot, a potential cause may be injury to one or more intervertebral disks. These disks function to stabilize the lumbar spine, absorb forces, and facilitate its range of motion.

The lower back is comprised of five lumbar vertebrae separated by intervertebral disks positioned in the anterior portion of the spinal column. The nucleus pulposus is a gel-like structure in the center of the disk that provides much of the strength and flexibility of the spine. In young, healthy disks, the nucleus pulposus is composed of 66–86% water, with the remainder consisting mostly of type II collagen and proteoglycans. The annulus fibrosis, surrounding this core, is made up of concentric layers (lamellae) of fibrous connective tissue, each oriented at about 60 degrees to the adjacent layer. This crisscross radial-ply design provides significant strength and helps prevent leakage of the nucleus pulposus, much like the reinforcement of a radial car tire. Finally, each disk is anchored to the vertebrae above and below by cartilaginous endplates.

Common disk injuries include disk bulge (the annulus remains intact but the disk extends beyond its normal boundaries), disk herniation (the nucleus pulposus pushes through the annulus), disk tear (the annulus itself tears), disk endplate injury (the nucleus pulposus intrudes into the vertebral endplate), disk degeneration (progressive breakdown leading to loss of disk height). Less common conditions include infection or neoplastic (tumor) invasion of the disk space. Importantly, disk injuries are not always symptomatic, which is why guidelines often recommend against advanced imaging for uncomplicated low back pain, as an observed disk herniation may not necessarily explain the patient’s symptoms.

Several studies have shown that it is nearly impossible to herniate a truly healthy disk. Rather, when an apparent injury follows a perceived trauma such as lifting with poor posture, it usually represents the culmination of a longer degenerative process in which the disk ultimately places pressure on a nerve root. Long-term risk factors for disk degeneration include obesity, family history of disk disease, and physically demanding occupations or leisure activities.

The good news is that many disk injuries can be managed non-surgically in a chiropractic setting using a multimodal approach. This may include spinal manipulation and other manual therapies, therapeutic exercise, physiotherapy modalities, and adjunctive anti-inflammatory strategies such as cryotherapy, dietary modification, and supplementation. In the short term, treatment focuses on restoring normal motion around the disk and reducing nerve root irritation. Over the longer term, the goal is to stabilize the spine and correct biomechanical issues that may place excess stress on the disk. If symptoms do not respond adequately, referral to a specialist for more invasive interventions, including surgical options, may be warranted.