Lower limb stress fractures are very common among runners due to the repetitive stress. The symptoms of a stress fracture are pretty clear: localised pain (aching or burning) somewhere on a bone. The pain will increase if you touch the specific area and will get worse when you run.
All tissues in our body adapt to the repetitive stress generated by running. Muscles and tendons need less time to modifies their mechanical properties. Bones, on the contrary, need months to adapt and strengthen. Therefore, high loads on your bones can create fractures.
What does science have to say?
Of course researchers have studied stress fractures. Here are some key facts:
- Vertical loading rate was found to be significantly higher in runners with stress fractures (1)
- Barefoot runners with a mixed landing pattern may sustain higher loading rates, compared with those who completely avoided heelstrike pattern (2)
How to avoid it?
It is pretty clear in the literature that stress fractures are correlated with high stress in the region where the fracture occurred. Higher forces and loading rates are primary risk factors for stress fractures. If you are a rear foot striker, stress will be applied primarily in your heel, tibia and knee. It you strike with your mid foot or front foot, a much higher stress will be applied in your metatarsal heads (i.e. your front foot bones).
Impact forces and loading rates can increase greatly if you fatigue. Your technique is therefore crucial to avoid stress fractures. Measuring and monitoring both impact forces and loading rates are crucial to avoiding fractures.
FeetMe Sport, is the ultimate running wearable and measures all key parameters related with stress fractures. As your personal running coach, FeetMe Sport tracks your risk of injury.