Stress fractures in the foot: warning signs for runners

Stress fractures are the runner’s injury that starts as a nuisance and ends a season if it’s ignored. The good news is that they’re predictable, and mostly preventable.

How a stress fracture happens

Bone is living tissue that constantly repairs tiny amounts of damage from everyday loading. Training makes it stronger, as long as it has time to adapt. When the number and size of loading cycles outpace that repair, microscopic damage accumulates until the bone cracks.^[1,3]

Stress fractures in runners always come back to an “error” in workload: too much, too soon, too fast.^[3]

Common sites in the foot and ankle

• Metatarsals, the long bones of the forefoot, especially the second and third.
• Heel bone (calcaneus): heel pain that hurts when you squeeze the sides of the heel.
• Navicular: a vague ache on top of the midfoot. This one is easy to miss and slow to heal.
• Fifth metatarsal near its base, on the outer edge of the foot, which can heal poorly.
• Lower leg: the tibia and fibula.^[1]

Warning signs

• Pain that starts during a run and eases with rest, then starts sooner each time.
• Pain that lingers after runs, then at rest, then at night.
• A specific spot on the bone that hurts to press.
• Swelling on the top of the foot or around the ankle.^[2]

If you have these, stop running and get checked. Running through a stress fracture can turn a crack into a complete break.

Who’s at risk

• A recent jump in mileage, speed work or hills, or a new running surface.
• New shoes, worn-out shoes or a change to minimal shoes.
• Not eating enough for the training you’re doing, and in women, missed periods, a sign of low energy availability.
• Low bone density, low vitamin D, or a past stress fracture.
• Foot structure, such as a high arch.^[1,3]

Diagnosis and treatment

X-rays often look normal for the first few weeks, until healing bone appears. When the history suggests a stress fracture and the X-ray is normal, an MRI confirms it.^[2] We take X-rays at the practice and arrange MRI when needed.

Most stress fractures of the foot heal with rest from impact, a walking boot or stiff shoe for a period, and a gradual return to running. Some higher-risk sites, including the navicular and the base of the fifth metatarsal, may need non-weight-bearing or surgery.^[1] Just as important is fixing the cause: training plan, shoes, nutrition, and bone health.

Getting back to running

Return is gradual and pain-free: walking first, then a walk-run program, building volume before speed. Increasing running cadence slightly (more, shorter steps) reduces the load on bone and can be part of preventing a recurrence.^[3] See fractures and trauma and sports medicine.

When to see a podiatrist