In addition to hairline fractures and complete fractures, there are also microfractures which are even tinier cracks or breaks in the bone.
Stress fractures occur most commonly in the weight-bearing bones of the foot where there is the highest amount of stress. These are typically the second and third metatarsal bones, but may occur elsewhere as well. Symptoms include pain and swelling in the affected area.
Metatarsal stress fractures are common and are often a result of repetitive stress or overuse, especially during activities such as running and jumping. This makes dancers and runners especially vulnerable to them.
Metatarsal stress fractures usually occur when there is a sudden increase in activity. This can be in terms of frequency – such as starting daily training immediately after a long rest period – or duration, like for instance, running a marathon without proper training beforehand.
Intensity may also play a part, such as when you suddenly start doing intense workouts without gradually ramping up to it. Bones that have been weakened by conditions such as osteoporosis or rheumatoid arthritis can also develop stress fractures over time.
While these microfractures can heal themselves with rest and adequate nutrition, it isn’t a good idea to simply keep powering through them. Depending on the cause of the microfractures, you may require further treatment.
For example, undiagnosed osteoporosis is one common cause of frequent metatarsal stress fractures, as well as an irregular foot shape which puts excessive pressure on the metatarsals.
In each case, a podiatrist will have to advise you on what course of action to take next in order to help prevent further injuries.