This can occur because the skeleton's ability to adapt to load is exceeded over time, in contrast to "ordinary" fracture injuries, which occur acutely. We also distinguish between two types of stress fracture: one caused by excessive load on normal bone tissue and the other caused by load on already weakened bone tissue, as with reduced bone density or osteoporosis. Stress reactions and stress fractures can occur in several places in our skeleton, but in runners they often develop in the foot.
Our foot is a strong, robust and composite structure that has to withstand heavy load when we run.
When running, our foot is in fact exposed to forces of up to 2.5-3 times our own body weight – at every single landing and every single push-off. Because of the large, repetitive load, the bones of the foot are particularly susceptible to overload in runners.
Risk factors and causes:
The most common cause of stress fracture in runners is often major changes in training habits, and shows itself in the form of:
- Overload: generally a high and rapid increase in training volume and intensity without sufficient recovery (rest, sleep, energy availability).
Combined with overload, there are also a number of other factors that increase the risk of developing stress fractures:
- Nutrition: generally inadequate energy intake, poor nutritional status and low levels of calcium and vitamin D can affect and weaken bone density.
- Biomechanics: anatomical deviations, previous injuries and muscular imbalances that can lead to unfavourable loading.
- Hormones: hormonal differences and lower bone density also give an increased risk of developing stress fracture in women and can, for example, be caused by menstrual disorders.
Common symptoms and signs:
- Pain that develops over time
- Pain when running or similar activity, but which eases with rest
- Pain at a specific point in the foot
In the early phase, the pain will often be present only during running-specific activity, but can later develop into pain during everyday activity as well.
Diagnosis:
The diagnosis is made by clinical examination and imaging. MRI is the first choice and the best tool for identifying and demonstrating stress fracture in most cases. X-ray is less accurate and makes it more difficult to detect stress reactions in the early phase, compared with MRI or CT.
Treatment and rehabilitation – back to running:
With the right treatment, the prognosis for returning to running after a stress fracture is generally good. The healing process and the rehabilitation plan do, however, depend on the extent and location of the injury.
Stress fractures in the foot are therefore categorised as either high-risk or low-risk stress fractures, based on where they occur and the likelihood of complications.
- Low-risk fractures: Injuries in the forefoot (except the 5th metatarsal), the heel bone (calcaneus) and injuries in less heavily loaded areas, as these usually require a shorter healing time and have a lower risk of complications.
- High-risk fractures: Injury in the upper part of the foot (navicular), at the base of the big toe (5th metatarsal) and other areas with poor blood supply, as these usually require a longer healing time and in some cases surgical treatment.
If the injury has occurred and running has been put on hold, it is important to start the right treatment and rehabilitation early to avoid complications, relapses and an even longer break from what you most want – namely to run again.
Treatment and rehabilitation focus on offloading and gradual return to activity and running. To avoid relapses, it is therefore important to get help clarifying the extent of the injury so that a tailored plan can be set up for the content and progression of the rehabilitation phases.
Rehabilitation phases:
Low-risk fractures (the metatarsals and calcaneus):
- Phase 1: Full offloading with minimal load on the foot. Use of a walker boot or a stiff-soled shoe may be necessary.
- Phase 2: Gradually increased weight-bearing and low-impact activities, for example water training, exercise bike, walking on a treadmill
- Phase 3: Gradual and progressive return to running, for example with an Alter-G treadmill to reduce the load or a "walk-jog" progression.
- Phase 4: Return to sporting activity with close follow-up.
High-risk fractures (navicular and 5th metatarsal):
- Phase 1: Full offloading for 6-8 weeks, often completely without weight-bearing. Water training and cycling without load may be considered.
- Phase 2: Gradual return to weight-bearing activity with careful progression.
- Phase 3: Gradual return to sport-specific activity once the symptoms have disappeared.
- Phase 4: Full return to activity with close follow-up to avoid relapse and re-injury.
In summary:
Stress fracture is a condition that should be taken seriously and that needs the right treatment and follow-up to avoid relapse – so that you can get back to running as quickly as possible. By being aware of the risk factors for developing stress reactions and stress fractures, those of you who are active will also find it easier to make choices and take measures in your training routine that will help reduce the risk and prevent the condition.
About the author
Pål Oscar Christensen (b. 1993) is an osteopath and trained at Høyskolen Kristiania in Oslo. He works day to day at Behandlerverket Kolbotn, where he follows up his patients and clients with manual treatment and rehabilitation, as well as training guidance and testing. Pål Oscar is himself an active runner with a particular interest in long-distance running. During his osteopathy training he also wrote his final diploma thesis on running-related injuries in ultrarunning. Kondis members get a 15 per cent discount at Behandlerverket, which offers treatments in osteopathy, chiropractic, physiotherapy and manual therapy.