Stress Fractures in Runners
Blog by Mike Stewart Physiotherapist
Stress fractures can be a common injury in athletes especially runners. A stress fracture is a micro fracture in the bone as a result of repetitive loading. There is a fine balance between fatigue damage and the remodelling response of bone. Marked increases in activity may lead to greater fatigue damage than the body can remodel and repair leading to a stress fracture. They can occur in virtually any bone in the body but in runners are most commonly seen in the tibia, metatarsals, fibula, navicular, femur and pelvis.
Ultra-runners usually run trails and as a result are less at risk of stress fractures than road runners. Trails reduce the load on the shins but there is a resultant increased load on the foot, making metatarsal stress fractures more common in this group.
Predisposing Fracture Include:
• Increasing frequency and intensity of training loads
• Inadequate recovery times
• Hard or cambered training surfaces
• Inappropriate footwear
• Previous history of stress fracture
• Excessive hip adduction
• Leg length discrepancy
• Poor foot and lower limb biomechanics
• Prevalence is greater in female athletes, especially where there is an energy imbalance between calories expended and calories taken. This can in lead to changes in the menstrual cycle and a resultant impaired bone health.
Insidious onset of localized pain or tenderness at the fracture site
Pain that occurs and intensifies with exercise
Pain in the early stages diminishes during rest
Gradually increasing pain to the stage where the pain does not settle with rest (later stage)
Stress fractures are primarily diagnosed by the history and clinical signs. X-ray is usually the first line of investigation but a number of stress fractures will not be evident on x-ray image. In these cases your Doctor may refer you for an MRI, CT or Bone Scan to confirm or exclude the presence of a stress fracture.
Management of a stress fracture involves cessation of the precipitating activity. With correct management most simple stress fractures heal within 6-8 weeks of relative rest.
There are some exceptions with complications, including delayed union and non-union occurring. This group is known as the high risk stress fractures and usually require more specific treatment. High risk stress fractures are seen at the femoral neck, talus, navicular, metatarsal base, sesamoids, 5th metatarsal base and anterior tibial cortex. These fractures take considerably longer to heal and in some cases may require Orthopaedic intervention.
There are a number of options for maintaining some level of fitness while awaiting the fracture to heal, dependent on its location.
Aqua jogging, swimming, cross training and stationary biking may be options to maintain a level of cardiovascular fitness without affecting the healing process .Remember to focus on what activity you can do and not what you can’t do during this period of healing.
Prior to any return to activity, your Doctor or Physiotherapist will have reviewed your pre injury training schedule, biomechanics and muscle balance to help to identify any faults that predisposed you to developing the stress fracture in the first place .
Once you have the green light from your Health Professional to resume training you will need to have a structured programme with progressive loading and adequate rest days.
Start walking, mix and match surfaces, gradually increase distance, introduce hill work then add in jog/walk options before starting running. During this time ensure you monitor your stress fracture site for any increasing tenderness which may indicate you are pushing it too hard. Keep your goals realistic and accept that it may take a number of weeks to safely return to your pre injury mileage.
Take home message is listen to your body and seek Professional advice early when things start to go wrong.