Femoral Neck Stress Fracture in Marathon Runners: The Injury You Can’t Run Through

Marathon training demands thousands of repetitive impacts through the hip. Most runners expect sore muscles, tight hips, and the occasional niggle — but one injury hides in plain sight and can turn catastrophic if ignored:

The femoral neck stress fracture.

It is rare, but it is one of the most dangerous running injuries because it often masquerades as a simple hip flexor or groin strain — until the bone breaks.

Understanding how it presents can save a season, a career, or even a hip replacement.

What Is a Femoral Neck Stress Fracture?

The femoral neck is the narrow bridge of bone connecting the ball of the hip joint to the shaft of the femur.

With every running stride it absorbs:

• Bodyweight

• Ground reaction forces

• Powerful muscle pull from the hip flexors, glutes, and adductors

When training volume rises faster than bone can adapt, microscopic cracks develop. If loading continues, those cracks coalesce into a stress fracture.

Unlike shin or foot stress fractures, a femoral neck fracture sits inside the hip joint — which is why it is medically serious.

Why Marathon Runners Are at Risk

Marathon training creates a perfect storm:

• Rapid mileage increases

• Fatigue-altered running mechanics

• Long runs on tired legs

• Inadequate recovery

• Low energy availability

• Poor bone density

Each step adds load to the femoral neck. When recovery is insufficient, bone remodelling falls behind damage accumulation.

Eventually, the bone begins to fail.

How It Usually Presents

This injury is rarely dramatic at first. It almost always begins subtly.

1. Deep Groin or Front-of-Hip Pain

Most runners report:

• A dull ache deep in the groin

• Or pain in the front of the hip

• Sometimes felt in the thigh

It is not superficial. It feels deep and hard to pinpoint.

2. Pain That Worsens With Running

Early on:

• Pain may warm up

• Disappear mid-run

• Return afterward

As the fracture progresses:

• Pain appears earlier in the run

• Persists longer

• Becomes harder to ignore

Eventually it hurts even when walking.

3. Pain With Impact and Weight-Bearing

Red flags include pain with:

• Running

• Hopping

• Climbing stairs

• Standing on the affected leg

Many runners notice they limp after workouts, even if they can still push through during the run.

4. Pain at Night or at Rest

As the injury worsens, pain may:

• Throb at night

• Ache when lying on the side

• Be present even without movement

This is a critical warning sign.

Why It Is So Often Missed

Femoral neck stress fractures are commonly misdiagnosed as:

• Hip flexor strains

• Adductor strains

• Labral injuries

• Sports hernias

• Low back referral

Stretching and massage may even temporarily reduce symptoms — but the bone continues to crack underneath.

Runners are particularly dangerous patients because they are:

• Highly pain tolerant

• Conditioned to train through discomfort

• Motivated by race deadlines

Unfortunately, this injury does not tolerate heroics.

What Happens If You Keep Running

If the stress fracture progresses:

• The femoral neck can snap completely

• The hip can become unstable

• Emergency surgery is required

In severe cases this can mean:

• Screws

• A plate

• Or even a hip replacement

This is why early diagnosis matters so much.

When to Suspect It

A marathon runner should treat hip or groin pain as urgent if:

• It came on gradually with training

• It worsens with impact

• It causes limping

• It hurts at night

• It does not respond to rest, stretching, or manual therapy

An MRI is required — X-rays are often normal early on.