Top 5 Causes of Low Back Pain

Demystification of complicated low back (lumbar) problems

Bad news—most people will experience low-back pain. If you haven’t experienced it yet, consider yourself lucky, but if you or a loved one have, you are not alone. 60 to 80 percent of individuals will experience a serious episode of low-back pain at some point in their lives. In those moments of pain and immobility, you realize how important your back is. As a spine surgeon, I see all variety of low-back issues. Although I go into detail about these issues in my book, The Spine Encyclopedia, in this post I want to provide a quick road map of the most common causes.

First, we have to understand the structure and function of the lumbar spine. The lumbar spine consists of vertebral bones linked together by facet joints, muscles, ligaments, and discs to form this incredible structure that suspends your torso upright. Obviously, the bones do not change shape as you move, but your facet joints, discs, and ligaments are elastic and provide support while also allowing motion. The most vital function of the lumbar spine is to protect the nerves that course from your spinal cord to your extremities and exit through small tunnels known as neural canals or foramina.  

As you live your life, your spine allows you significant freedom of motion, but degenerative arthritis can set in the facet joints and the intervertebral discs over time. Typically, the disc starts to break apart and shrink, losing its plump, hydrated configuration. When this occurs, the disc loses its thickness, and you lose height. As you try to hold yourself upright, increased load is placed on the facet joints, causing them to grind together and wear out. This process is known as lumbar degenerative disc disease (see number 2 below). When the cartilage of the facet joints wears out, the bones can grind on one another, causing loosening—think of gears wearing down and slipping. Lumbar degeneration is the common culprit for many back problems, so let’s jump right into the top 5 causes of low-back pain. All have complicated medical terms, which we will demystify.

1.     Lumbago: from the Latin Lumbus (hip or loin), lumbago is a general term to describe muscular pain of the low back. The back is a complicated suspension bridge with thousands of struts and muscular attachments. It can be strained easily, resulting in crippling low-back pain. The good news is that most of this pain is temporary, and the body can quickly heal these problems. It is very scary when it happens, but this condition is common and will not require surgery.

2.     Lumbar spondylosis: spondylosis is a catch-all term that refers to degenerative disease of the spine. When your facet joints grind down and become arthritic, that’s spondylosis. When your discs shrivel up and the vertebral bones come into contact, forming bone spurs, that’s also spondylosis. A common descriptor for spondylosis is “degenerative disc/spine disease.” It’s very painful and can cause low-back pain in and of itself, but as the degeneration worsens, bone spurs form and can encroach on the delicate nerves of the spine, resulting in severe back and leg pain. Degenerative spondylosis can also cause a curvature of the spine to develop known as scoliosis, which can also be very painful.

3.     Lumbar spondylolisthesis: the term spondylolisthesis originates from the Greek spondylo (the spine) and olistesis (to slip and fall). The colloquial name for a spondylolisthesis is a slipped disc, where a higher vertebra shifts forward in relation to a lower vertebra. This can cause a kink in the spinal canal and pinch off all the nerves. Spondylolisthesis has several causes. The facet joints/discs normally hold the vertebra together like links on a chain, and when they wear out (spondylosis) the upper vertebrae of the segment can slip forward, a condition known as a degenerative spondylolisthesis. If the facet breaks off, this is known as spondylolysis. Spondylolisthesis can cause severe low-back pain and leg pain (sciatica).

4.     Lumbar stenosis: Stenosis is probably the most common term you will hear at the spine surgeon’s office. The term stenosis comes from the Greek stenos meaning “to narrow” and is used to describe medical conditions where a tube structure becomes obstructed or narrowed. In the spine there are two areas that can become stenotic from degeneration: the spinal canal and the neural canals. The spinal canal carries the spinal cord and nerve roots in the thecal sac. The neural canals are where the nerves exit the spine. If these areas become narrowed or stenotic, they can pinch the nerves, causing back and leg pain.

5.     Lumbar flat back: Your back has a natural curve that helps you maintain a harmonious balanced posture when you are upright. The curvature of the lumbar spine is known as lordosis, which is a U-shaped parabola that occurs because the discs and vertebrae are naturally wedge shaped, like the stones composing a bridge that are built to last centuries. When diseases such as disc degeneration occur, the natural shape of the spine segment can be lost. Your body naturally tries to compensate for this loss by increasing wedging of the other discs so you can maintain an upright position—known as your sagittal alignment. As the remaining discs strain to maintain this abnormal shape, they also become exposed to increased stress that can result in their early demise. No one has the same lumbar lordosis, so spine surgeons have figured out how much lordosis you need based on a measurement in your pelvis, known as the pelvic incidence. As you lose lumbar lordosis with age, you tend to tilt your pelvis backward to compensate and maintain your sagittal alignment by straining the low-back muscles. The muscles become irritated and fatigued in trying to hold you upright. Loss of lumbar lordosis can result in severe chronic low-back pain.

When confronted with these diseases, the spine surgeon can become your best friend, as they can offer a pathway through pain and discomfort, most of the time guiding nonoperative treatment. When reconstructive surgery is considered, spine surgeons aim to re-create the normal alignment and configuration of the spine that has been deformed by slipped discs and degeneration. We aim to unclog the pipe, so to speak, by removing stenosis. Although spine surgery is a last resort that most people will naturally avoid if possible, this final step can significantly improve your back pain and give you your life back.