5 Hidden Causes of Chronic Low Back Pain in Active Adults

Here's a frustrating situation I see constantly at Leverage Fitness Solutions: someone who is genuinely active — they exercise regularly, they're not overweight, they take care of themselves — and they still have chronic back pain. They've been told to strengthen their core. They've done it. They've been told to stretch. They've done it. They've been told to lose weight. They didn't need to.

And their back still hurts.

If this is you, the problem isn't that you're not trying hard enough. The problem is that the standard advice for back pain is built around sedentary, deconditioned adults — and it misses the specific causes that affect active people. Here are the five hidden causes we find most often in active adults who come to us in Sandy, Millcreek, and across the Salt Lake Valley.

1. Lateral Instability — The Stability Gap Nobody Talks About

Most back pain programs focus on anterior core strength — planks, dead bugs, hollow holds. These are valuable. But they address only one plane of stability. Your spine also needs to resist lateral forces — the sideways loads that occur with every step you take, every golf swing, every time you carry something in one hand.

The lateral stabilizers — the quadratus lumborum, the lateral obliques, the hip abductors — are dramatically undertrained in most fitness programs. And when they're weak, the spine compensates with every asymmetrical movement you make.

Here's the test: can you hold a side plank for 90 seconds on each side? If not, you have a lateral stability deficit — regardless of how strong your front plank is. This is one of the most common findings in active adults with persistent back pain, and it's almost never addressed in standard back pain programs.

The fix: the side plank (done with the correct 10-second hold protocol), loaded carries, and the Pallof series. These are in the Healthy Back Handbook's Resilient Spine Protocol.

2. Extensor Weakness — The Forgotten Half of Your Core

When people think about core training, they think about the front — the abs, the anterior core. But the posterior core — the spinal extensors, the multifidus, the erector spinae — is equally important for spinal stability, and it's the half that most training programs neglect.

Dr. Stuart McGill's research identifies extensor endurance as one of the strongest predictors of long-term spine health. Specifically, the ability to hold a back extension for 3 minutes is associated with dramatically reduced back pain risk. Most active adults, even those who train regularly, can hold a back extension for 30–60 seconds at most.

The reason this matters: the extensor muscles are the primary shock absorbers for the lumbar spine during loaded activities — lifting, carrying, hiking, golf. When they fatigue, the passive structures (discs, ligaments, facet joints) take over. That's when injuries happen.

The fix: progressive back extension holds, starting from where you are and building toward the 3-minute benchmark. The Healthy Back Handbook's Stage 3 protocol takes you through this systematically.

3. Thoracic Restriction — The Back Pain Cause That Isn't in Your Back

This one surprises people. Your thoracic spine — the mid-back — is supposed to be the primary site of rotation and extension in your torso. When it's restricted (which it almost always is in adults who've spent years at a desk, in a car, or hunched over a phone), the lumbar spine has to compensate.

Think about a golf swing, a tennis serve, or even turning to check your blind spot while driving. All of these require thoracic rotation. If your thoracic spine can't rotate, your lumbar spine does — and the lumbar spine is not designed for that kind of rotational load. This is a primary driver of back pain in golfers, tennis players, and anyone who does rotational activities.

Here's the thing: you can have a perfectly mobile lumbar spine and still have significant back pain if your thoracic spine is locked up. And no amount of lumbar stretching will fix a thoracic mobility problem.

The fix: thoracic rotation and extension mobility work — foam roller thoracic extensions, seated thoracic rotations, open book stretches. These are included in the Healthy Back Handbook's mobility protocol.

4. Hip Mobility Asymmetry — When One Side Doesn't Match the Other

Most active adults have some degree of hip mobility asymmetry — one hip moves better than the other. This is especially common in people with a dominant sport (golf, tennis, pickleball) or a history of lower limb injury. And it's one of the most overlooked causes of chronic back pain.

Here's why: when one hip can't move through its full range of motion, the lumbar spine compensates to complete the movement. Over thousands of repetitions — every step, every squat, every lunge — this asymmetrical loading accumulates. The side of the lumbar spine that's compensating for the restricted hip gets overloaded. That's usually where the pain is.

The fix is not to stretch the tight hip — it's to restore symmetrical hip mobility and then retrain the movement patterns that have been compensating for the asymmetry. This requires assessment to identify which hip is restricted and in which direction, which is why a personalized approach is more effective than a generic hip stretching routine.

5. Training in Flexion — When Your Workout Is Causing Your Pain

This is the one that's hardest for active adults to hear, because it means their training might be contributing to their problem.

As I mentioned earlier, approximately 90% of low back pain involves flexion intolerance — pain that comes from loading the spine in a bent-forward position. And a significant portion of popular fitness activities load the spine in exactly this direction: crunches, sit-ups, toe touches, rounded-back deadlifts, certain yoga poses, rowing, cycling in an aggressive position.

If you're doing these activities regularly and you have flexion-intolerant back pain, you're repeatedly loading your spine in the direction that's causing your problem. The fact that you're fit and active doesn't protect you — it just means you're doing it more consistently.

This doesn't mean you have to give up your favorite activities. It means you need to address the flexion intolerance first — through the McKenzie press-up protocol and the Big 3 stabilization work — and then modify your training to reduce flexion loading while you rebuild your stability foundation.

To understand the specific exercises that address these five causes in the right sequence, read our comparison of McKenzie and core strengthening approaches. And to understand why the cycle of flare-ups keeps repeating even when you're active, read about the real reason low back pain keeps coming back. Our training programs are specifically designed for active adults who want to address these root causes, not just manage symptoms.

Frequently Asked Questions

How do I know which of these five causes applies to me?

The most reliable way is a movement assessment with a trainer who understands spine biomechanics. We can identify your specific stability deficits, mobility restrictions, and movement pattern issues in a single session. That said, the Healthy Back Handbook's assessment protocol will give you a good starting point for identifying your directional preference and your Big 3 baseline.

I've been doing yoga for years and I'm very flexible. Can I still have these problems?

Yes — and yoga practitioners are actually overrepresented in the group with lateral instability and extensor weakness. Yoga builds flexibility and anterior core strength, but it often neglects the lateral stabilizers and posterior chain. Hypermobile yoga practitioners frequently have back pain caused by instability rather than tightness — and more stretching makes it worse, not better.

I run 30+ miles per week. Could running be contributing to my back pain?

Possibly. Running is a high-repetition, asymmetrical activity that requires significant lateral stability and hip mobility symmetry. If you have deficits in either area (causes 1 and 4 above), running will repeatedly load those deficits. This doesn't mean you need to stop running — it means you need to address the deficits so your spine can handle the demands of your training volume.

I'm in Sandy / Millcreek — how do I get started?

Our studio is at 7833 S Highland Drive in Cottonwood Heights — about 10–15 minutes from Sandy and Millcreek. Start with the free Healthy Back Handbook to get a sense of our approach, then contact us to book your free Longevity Blueprint Calibration.