Stress fracture advice for runners
Everything you need to know about stress fractures
A stress fracture is a crack in a bone that results from repetitive sub maximal physical loading. Running requires repetitive movements, so stress fractures are unfortunately a common occurrence.
What causes stress fractures?
As muscles become fatigued, their ability to absorb impact forces diminishes. This causes a redistribution of impact forces resulting in increased stress at focal points in the bone. If stress is applied at this point repetitively a tiny crack opens up in the bone and this is what we call a stress fracture.
There are a number of predisposing causes to a stress fracture; lets break them down into extrinsic and intrinsic factors.
Predisposing factors – Extrinsic
Like most injuries, over-training and a lack of recovery play a significant part in the cause of a stress fracture. The amount you train, the duration, and the intensity of your sessions, will all play a factor. If these factors are too excessive, injuries will likely occur.
On top of this, inadequate recovery between sessions will significantly increase your chances of picking up an injury like a stress fracture. This can explain why beginner runners, or those coming back to running after a long layoff, can be commonly affected.
If your regular technique has changed, even slightly, then the impact forces put through your body can lead to a fracture. Changes to technique could be caused by something as small as a blister, but can lead to an area of your foot that is not used to, or able to, handle the load.
The surface on which you run on can affect the load and force through your body, and can also affect your technique. Doing too much running on hard surfaces can increase your chances of getting a stress fracture, particularly if the quantity, duration, and intensity of your sessions are too excessive.
If you are not running on a flat surface, then the camber of the surface can lead to a change in the mechanics of your running gait. This can affect the load on the body and could be responsible for a number of injuries, including stress fractures.
Inappropriate or worn-out footwear can also lead to stress fractures. If your trainers haven’t been fitted correctly for you by a specialist, then you may be wearing something that is unsupportive or is trying to correct something that doesn’t need correcting.
If you haven’t changed your footwear in a while, and your mileage is high, then there’s a good chance that they could be getting worn out. This will prevent them from doing the job they were intended for, can lead to a change in load through your body, and ultimately lead to injury.
Poor or inadequate nutrition can play a big part in injury and injury prevention. Good bone health is important, and it’s fair to say that poor bone density and osteoporosis can increase chances of stress fractures.
Calcium consumption is the major player in bone health. If not enough calcium is consumed within a regular diet then the body will take calcium from the stores within bones to meet its needs. This can heighten the risk of stress fractures occurring.
Predisposing factors – Intrinsic
There are a number of intrinsic biomechanical factors that will influence the likelihood of stress fractures occurring.
Muscles have a number of important functions, such as providing our skeletons with the ability to move. They also act as a shock absorber, and can reduce impact forces.
Strong muscles reduce the forces transmitted to the bones by dampening the impact. Strong muscles also help keep bones and joints aligned so that less force is transferred to the bones.
Muscle endurance is particularly important in runners. The calf muscles, quadriceps, and glutes all need to have good levels of endurance to cope with the demands of repetitive locomotion. When they fatigue, compensation will occur, and injuries can crop up.
If joints or bones are misaligned it can cause the length of a muscle, or muscles, attached to it to change thus impacting its performance and ability to be strong.
Our bodies are complicated structures, and misalignment can occur anywhere in the body. A good starting point with runners is looking at the hips, knees, and ankles. Leg length discrepancy is also something that needs looking at and addressing.
If a structure is misaligned it will put pressure on different areas within the body. This can lead to a domino effect of dysfunction, resulting in compensation, and injury occurrence.
Lack of flexibility
Poor flexibility can affect the strength of muscles, running efficiency, and is a contributor to dysfunction and potential injury. Tight calf muscles, for example, will affect the efficiency of your foot’s ability to cushion the impact forces when landing. Over a period of time, this will lead to problems.
Sex, size and body composition
The repetitive nature of running, and the force applied to the foot as it hits the ground, is about two to three times the force of the individual's body weight. Over a period of time, and distance, this will exponentially increases the stress on a runner's foot.
It is important to look at your body shape, and be honest about your muscle and fat mass. It may require looking at, and addressing, your nutritional intake.
Females seem to experience stress fractures more commonly than men. Eating disorders (bulimia or anorexia), amenorrhea (infrequent menstrual cycle), and osteoporosis are the three main contributors to this. These all lead to a decrease in bone mass, and result in an increased chance of getting a stress fracture.
Where do stress fractures occur?
Stress fractures may occur in virtually any bone in the body, but the most common sites of stress fractures are the second and third metatarsals of the foot. Stress fractures are also common in the heel (calcaneus), the outer bone of the lower leg (fibula), and the navicular (a bone on the top of the midfoot).
What are the symptoms of stress fractures?
Pain that develops gradually, increases during the run, and decreases with rest.
A spot on the bone that is extremely tender to press.
It hurts if you hop on that leg.
How are stress fractures diagnosed?
X-rays are commonly used, although sometimes stress fractures can’t be seen on regular X-rays or will not show up for several weeks after the pain starts. Occasionally, a CT scan or MRI will be used.
How are stress fractures treated?
The treatment generally requires avoidance of the activity that has caused the injury. The majority of stress fractures heal within six weeks of beginning relative rest.
If running is resumed too quickly, larger, harder-to-heal stress fractures can develop. Re-injury also could lead to chronic problems where the stress fracture might never heal properly.
In addition to rest, shoe inserts or braces may be used to help these injuries heal.
Stress Fracture Prevention
Build your mileage gradually.
Give your muscles, bones, and joints a break from repetitive running by cross training. Non-weight bearing activities such as cycling or swimming will help. Also, add some strength training and flexibility exercises to your weekly training.
Maintain a healthy diet. Calcium and Vitamin D rich foods should be included in your daily meals.
Be aware of your footwear. Do not run in old, worn out, or poorly fitted trainers.
If pain or swelling occurs, immediately stop the activity and rest for a few days. If continued pain persists, seek out a health care professional.
It is important to remember that if you recognise the symptoms early and treat them appropriately, you can avoid a longer lay off from running.
Get regular maintenance work from a professional, such as a chiropractor, so they can ensure the alignment of your joints and bones are optimal for you, and your muscles are working efficiently
Take home message
If something feels like a bone pain, don’t try and be brave and push through it. Stop immediately, even if it’s mid run. Seek the advice of a health care professional that can assess the injury.