Why Does My Lower Back Hurt When Running?

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When I set out for a long run, I expect a few things to hurt — my feet, my ankles, my legs. By now, I'm prepared for that though. I have my stretches to support my ankles, my supportive sneakers like UA HOVR™ Phantom RN Running Shoes ($140) to help minimize the impact of each step, and my lower-body exercises to strengthen my entire posterior chain.

But one part of my body I didn't expect to ache (but routinely does while on my double-digit run adventures) is my lower back. To help me understand what gives — and more importantly, if I should be concerned — I spoke to Dr. Theresa Marko, doctor of physical therapy and board-certified clinical specialist in Orthopaedics in New York City who has more than 20 years of experience.

So why does the low back hurt?

"Basically it fundamentally comes down to fatigue," explained Dr. Marko, who noted there are two types of muscle fibers, slow-twitch and fast-twitch. "The fast-twitch muscles are the more superficial muscles and have a lot of energy stored in them. When you first start off on a run, it puts fast-twitch muscle fibers in high gear. They sprint off and allow you to go."

However, Dr. Marko explained these kinds of muscle fibers only have a certain shelf life, and they start to lose their energy stores once they fatigue. As you're running longer and longer, fast-twitch muscle fibers run out of their energy stores and aren't operating at full capacity.

"So without those muscle fibers at full function, you are now going to have joint deviations and dysfunctions," said Dr. Marko. From there, it's almost a trickle effect of common aches and pains, including quadricep and kneecap issues. "If the quadriceps are fatiguing, it is no longer going to do a great job of helping that kneecap to track properly in the groove in which it sits," Dr. Marko said. "Another really common thing that happens is the sides of our hips fatigue, so the gluteus medius muscle. This muscle is so important for providing pelvic and lumbar stability. When it fatigues, we will now be overworking our lumbar superficial muscles and get back pain there."

So basically, my back pain is simply a result of the fatigue I'm feeling in my lower body.

Is the pain related to anything?

The short answer is yes: lower back pain is tied to a few different causes. For starters, the lack of pelvic stability can be one, said Dr. Marko. Another supercommon related cause is inflexibility of the hips. "If your hip flexors are tight, then your hip cannot go into hip extension, which needs to happen when you run," she said. "If your hip will not go into hip extension, then your spine will. This excessive extension on your lumbar spine and pelvis causes shearing and a constant banging." Another thing tight hip flexors do, according to Dr. Marko, is cause your lower back to arch because the hip flexor has shortened and pulls you into an anterior pelvic tilt.

In addition, she explained factors like core stability, pelvic stability, knee tracking, flexibility of hip flexors, hamstrings, and calf, and ankle mobility may all be connected for some. A physical therapist may also analyze a runner's step pattern and the shoes they wear.

Is it OK to power through aches and pains?

As a marathoner, I've always believed that I should power through to achieve my goal, but the answer may not be that simple.

Dr. Marko suggests to first slow down to a moderate jog for things to relax a little bit. If that doesn't work and severe pain, tingling, or numbness starts, Dr. Marko adds that a few stretches that work the booty, hip flexors, and hamstrings may be beneficial. Finally, trying the classic move of laying on your back, hugging your knees to chest while rocking left and right may do the trick.

"If these things don't improve your back symptoms, then it's time to go see a physical therapist," Dr. Marko added.