Low back pain is the number one condition treated by chiropractors with lumbar disc injuries leading the differential diagnosis categories for each low back pain patient. Let's first discuss the lumbar spine and it's anatomical details.
The lumbar spine is referred to by the non-medically minded as the low back or the small of your back. The lumbar spine is composed of five vertebrae that when properly aligned form a lordosis or inward curvature. Between each of these vertebrae lie a disc or more properly named an intervertebral disc (IVD). The IVD is made up of two components: the annulus fibrosis and the nucleus pulposus, better described as a jelly doughnut. The jelly in the middle of the doughnut represents the nucleus pulposis which is held in place by the actual doughnut or the annulus fibrosis. The nerves that supply the buttock and entire lower extremity do exit the lumbar spine and are often effected by disc injuries.
There are multiple types of disc injuries: discitis, disc herniation, disc bulges, disc fragmentation/sequestration, disc degeneration, etc. What I'm going to focus on in this blog are the disc bulges and herniations. Symptomatology for these two conditions can be identical in the form of radiating or traveling pain from the lumbar spine to either the buttock, the posterior thigh, the posterior knee, the plantar or bottom of the foot or as far as to the big toe. The causation of this pain pattern is determined by the level of IVD bulge or herniation and it's effect on the correlated nerve exiting at that level (see diagram, nerves are in yellow). Disc injuries can also be asymptomatic or cause little to no pain at all.
Mechanisms of injury can include but are certainly NOT limited to: poor lifting posture, sudden rotational moves, over-use injuries, poor lumbar spine biomechanics/support or can be as simple as bending over and picking up the newspaper. Diagnosis for these problems are often quick and are made through orthopedic testing, radiographs (although the IVD cannot be visualized on xray, the space where the disc lies is), and MRI. MRI is usually the "gold-standard" diagnostic imaging preferred for disc injuries as visualization of the lumbar spine osseous structures (the bones) PLUS the IVDs AND the nerves are all possible.
Treatment options are vast from conservative options ie. chiropractic care via spinal adjustments and therapeutic modalities to radical surgical procedures that can involve removing the disc and fusing the two adjacent vertebral bodies together or an insertion of a disc prosthesis.
For research and more information on what chiropractic can do for disc herniations and injuries see the following research: