What are risk factors for a running overuse injury?
As for many injuries, it is hard to identify one unique factor that puts you at risk of an overuse injury.
Remember the 4 main causes of pain with running? Let’s discuss each one.
Atypical foot mechanics: conflictual evidence exists. To this day, it would make sense but we cannot be sure that hyper-pronation, in isolation, puts you more at risk of getting injured.
Strength: when the foot pronates, the ankle unlocks and more muscle work is required to maintain stability. The tibialis posterior, if weak, will affect the control of the ankle joint movement. It also helps to support the arch of the foot. Therefore, a weaker tibialis posterior diminishes ankle stability and forces other muscles – like the soleus, part of your calf group – to work more, causing Achilles tendinopathy and/or overall calf tightness. It also adds stress to the plantar fascia, increasing the odds of plantar fasciitis development.
Anatomical alignment: because of the difference between static – or structural – alignment and dynamic – or functional – alignment, no study could clarify the real impact of flat/arched feet on the incidence of overuse injuries. Too many compensations may occur, especially from muscles, to exactly understand what may happen.
Flexibility: first ray hypomobility seems to be associated with increased rearfoot eversion. Reduced calf flexibility – or increased tightness- seems to be associated with increased energy absorption at the ankle during the first half of the stance. Which means more stress at the ankle.
In conclusion: with only one variable outside of its normal limits, it is unlikely to expect abnormal pronation patterns. But if you combine weak muscles, hypomobile joints, and flat feet, it can start to increase the load on various anatomical structures. And eventually leads to an injury.