Hip pain when running? You may need to strengthen your iliacus muscle

Ilias muscle soreness and exercise tips

Credit: Getty

Strong Women


Hip pain when running? You may need to strengthen your iliacus muscle

By Meg Walters

11 months ago

4 min read

Do your hips seize up every time you go for a jog? Here’s how strengthening a tiny muscle called the iliacus could make all the difference.


Running certainly isn’t for the faint of heart. While the post-workout endorphins make it worth it, there’s no denying that it can leave you with throbbing calves and aching hamstrings. One of the most common running complaints, though, is pain and tightness in the hips.

Mild hip soreness is normal after a long run (because you’ve just been using the muscle to power your legs). But if you start to experience frequent pain in the hips and pelvis that makes putting one foot in front of the other feel like an impossible task, you may be dealing with irritation or weakness of the iliacus.

What is the iliacus?

“The iliacus?” you might be thinking. “Never heard of it.” 

You probably have, but maybe not by that name. The iliacus is a key part of the larger and better-known hip flexor (the other main muscle being the psoas). Together, the iliacus and the psoas make up the hip muscle group that connects the spine with the inner hip. Essentially, it is these two muscles that kick into gear when you lift your leg.  

As PT Lucy Arnold puts it: “The iliacus is a muscle covering the surface of the pelvic bone, ranging through the hip and groin area.”

“Set within the hip region, the iliacus muscle contributes a lot to general function,” adds physiotherapist Miriam Daurat from Our Health Hub. “It’s involved in walking and supporting posture to working with the psoas major muscle to create powerful hip and trunk flexion. These movements allow us to bend down to tie laces and pick things up – as well as perform exercises like sit-ups and crunches.”

Woman in exercise clothes — iliacus muscle

Credit: Getty

Can your iliacus cause hip pain while running? 

According to a 2011 survey, roughly 10% of runners experience hip pain at least once a year. The difficulty is that it’s hard to pinpoint which muscle in the hip area is causing your pain. 

So how do you know if it’s the iliacus that is contributing to poor hip mobility and running pain?

“Symptoms of an irritated iliacus can include stiffness while running, decreased mobility and flexibility in hip flexors at the front of the thigh, as well as muscle tenderness,” Arnold says.  

Daurat explains that exercise can easily cause irritation in the iliacus. “Particularly in running, these small muscles can be overused to the point of injury,” she says. “The acceleration and deceleration in running, coupled with the forces travelling through the hips and legs, cause the tendon that attaches the iliopsoas to the femur to become irritated and inflamed.”

It’s not just the running that causes pain, either. The ilacus has to contend with a whole day sat down, too. “Regular time spent sitting for prolonged periods can cause the muscle to shorten,” says Daurat. “Reduced flexibility and weakness in the iliacus can result in hip stiffness and pain associated with muscle tightness.” A shortened iliacus can also result from skipping out on stretching after strength training or, you guessed it, running.

Woman doing a lunge to

Credit: Getty

How to strengthen (and lengthen) your iliacus

It’s important to keep the muscle both strong and supple – especially if you’re working on completing a running goal. Over time, tightness in the iliacus can lead to an ‘anterior pelvic tilt’, Daurat says. That’s when the pelvis is tilted forwards, creating an arch in the back. “Imagine the pelvis as a bucket of water – an anterior pelvic tilt would be as if the bucket was angled to tip water out of the front,” she says. 

If tightness in the iliacus causes this tilt, you may begin to experience back pain in the long term too. Here are some tips to help strengthen and lengthen your iliacus and banish hip tightness for good:

Get up and move

“Making a point to break up episodes of prolonged sitting can go a long way to decrease the likelihood of muscles becoming shortened and irritating during a run,” suggests Daurat. “After 30 minutes of sitting it is important to stand up and move around for a few minutes.”

Stretch after a run

Stretch, stretch, stretch. Before and after a run, try incorporating stretches like lunges and bridges into your routine. “While it is important to make sure the iliacus and other muscles are strong, it is vitally important to promote good flexibility to reduce the risk of injury and pain,” Daurat says.

“Many simple stretches can be done in the comfort of your home, including hanging leg and knee to chest stretches,” says Arnold. “But,” she adds, “always consult a professional before doing any intensive stretching to prevent further injury.”


Images: Getty

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