The muscles and tissues surrounding the tibia, or commonly referred to as your "shin bone" or just merely "shin", are often the culprit in a variety of running injuries. Think medial tibial stress syndrome ("shin splints"), exertional compartment syndrome, Achilles tendinopathy and calf strains - the list goes on.

When loading up the shin bone, it is essential to determine your optimal load for increasing bone density - more bone being formed than broken down. If you apply too little a load, you won't get that increase in density and too great a load, the amount of bone being broken down is greater than the amount of bone being form. When the tibia itself has undergone too much repetitive stress, we begin to observe a bone stress response. This can lead to a stress fracture - a crack in the bone. The Fredericson classification system below gives a visual indication of the bones response under MRI. 

While stress fractures are not common in the non-exercising population, they are thought to represent 0.7-20% of sports medicine clinic presentations.

Across both sexes, those who have sudden increases in training load are at risk; however, females are at greater risk when comparing male and female athletes. It has been suggested that menstrual disturbances, caloric restriction, lower bone density, muscle weakness, and leg length differences are important risk factors.

Runners typically complain of a sudden focal pain on their shin bone that is nasty to touch. This pain also appears early in impact-related exercise and is worse during the landing phase of running.

While they generally affect one leg at a time ("unilateral") and most commonly involves the tibia, you cannot rule out other bones or symptoms in both legs ("bilateral").

Think you might have a stress fracture? Go and see a sports physician, physiotherapist, or podiatrist ensure you stay one step ahead of your treatment.