By Dr. Brant Hulsebus, Rockford Chiropractor
One of the most common things I hear in practice is, “I have an L5 disc problem.” Whether it’s from an MRI, an X-ray, or something a doctor mentioned in passing, many patients walk in convinced their lower back pain is all about the L5 disc. But here’s the truth: not every thin or abnormal L5 disc is a cause for alarm — and in many cases, the pain isn’t coming from the L5 at all. Let’s look at L5 disc pain vs SI joint issues.
What Makes the L5 Disc Unique
The L5 is the very last vertebra in your lumbar spine, sitting just above your sacrum (what many call the tailbone). In most people, there’s a disc between the L5 and sacrum — but this is one of the most common places where the disc can look “different.”
As children grow, the sacrum fuses from multiple bones into one. The L5 sometimes fuses with the sacrum, which creates what’s called a rudimentary disc — a very thin disc that never fully develops. On an X-ray, it can look alarming if you don’t know what you’re looking at, but often it’s just the way you grew.
Clues It’s Not a “Bad” Disc
- No sciatica history: The L5 nerve is part of the sciatic nerve. If you’ve never experienced sciatic pain, foot weakness, or numbness, that likely means the nerve isn’t irritated.
- No arthritic changes: A true degenerative disc problem usually shows extra calcium build-up (bony spurs) on X-rays. If that’s missing, it may not be a wear-and-tear issue.
- Normal sacral development clues: If we see other rudimentary discs in the sacrum, it’s a sign this is just how your spine formed.
When Pain Is Really an SI Joint Problem
Another common situation happens when someone is told they have an L5 disc issue. Their pain often points somewhere else entirely. The SI joint — where the sacrum meets the hip bones — sits right next to the L5. It is often the real culprit. I’ve seen patients get injections and nerve ablations for the L5 with no relief. When we adjust the upper lumbar spine or address the SI joint, they finally feel better.
Why X-Rays Matter with L5 disc pain vs SI joint
The only way to truly know what’s happening in your spine is to look. Chiropractic X-rays taken while standing help us see posture, alignment, and whether a disc issue is structural or degenerative. If you already have films, bring them in — we can often review them without retaking new ones.
When to Get a Second Opinion
If your doctor told you that you have an L5 disc problem, but you’ve never had sciatica, don’t see extra calcium on your X-rays, and haven’t experienced symptoms below the knee, consider asking a chiropractor for a second opinion.. You might be chasing the wrong problem.
Bottom Line
The L5 disc gets blamed for a lot of back pain it doesn’t cause. Before you commit to long-term treatment plans, make sure you know whether your pain is truly coming from the L5, the SI joint, or somewhere else. A proper chiropractic exam — including X-rays — can help you get the right care and avoid unnecessary procedures.
Have questions about your L5 disc or SI joint? Contact our Rockford chiropractic office and schedule a consultation. We’ll review your films, perform a detailed exam, and get you on the right track. Learn more about Chiropractic at International Chiropractic Association .