Calcaneal bone stress injuries refers to injuries to the Calcaneal bone, commonly known as the heel bone.
The injuries range from bone stress reactions (aka. “bruised bone”) to bone stress fractures and they can cause considerable heel pain when you put pressure through the heel.
Bone stress injuries arise when the rate of bone break down (which is normal with activity) is happening faster than the body can repair it (which is normal after activity).
This mismatch eventually leads to the bone reacting, which is when the pain begins to be felt. As the reaction worsens and the bone stress increases, the bone cracks and becomes a bone stress fracture.
In the adjacent Xray image, you can see a white-ish line in the upper part of the Calcaneus, extending abut halfway down through the bone. That’s a bone stress fracture line.
Note: Xrays don’t often show bone stress fractures and are not the preferred image to diagnose them.
What are the symptoms of Calcaneal bone stress injuries?
The main symptom of Calcaneal bone stress injuries is heel pain when pressure is applied to the area (like walking on it).
The heel pain can be difficult to localize to one location and may be felt underneath the heel, on the side/s of the heel or back of the heel. Sometimes the pain can even feel like it moves around, shifting from one spot to another during the day.
The pain can hang around for hours after any loading activity like walking or running – as it shifts from Calcaneal bone stress reaction towards a stress fracture, the pain can be worse than usual for days after the activity.
This is one of the other identifying symptoms of Calcaneal bone stress – the aching after activity. This might be a continuous ache even when you don’t have pressure on the heel, or it might be aching overnight while you’re laying down.
Why do you get a Calcaneal bone stress injury?
The bone stress begins gradually as the rate of bone cell breakdown exceeds the rate of bone cell healing. Although bone cell breakdown sounds like a bad thing, it’s actually quite normal.
As you exercise, the bones sustain tiny amounts of breakdown. That stimulates the bones to repair and regenerate, making them stronger with exercise. That’s why it’s recommended that everyone should do some weight-bearing exercise for healthy bones.
But if the breakdown increases and/or the healing rate decreases so that breakdown is greater than repair, you’re on your way to a bone stress injury.
Although the process is typically a gradual one, the pain can hit suddenly in some cases. That doesn’t mean that your breakdown happened quickly, just that it was brewing away at a level that made it sensitive to pressure and you suddenly hit the affected area.
If we look at causes of increased bone cell breakdown:
- applying a load that the bone wasn’t ready for (like starting a new sport)
- more training time (same rate of breakdown but for longer periods)
- poor or fatigued technique (the body is less able to protect itself from impact), and
- increasing bodyweight (this can happen with pregnancy or periods of over-indulging)
The causes of reduced bone cell repair are:
- Poor or inadequate nutrition
- Hormone imbalances or deficiencies
- Low Vitamin D or calcium levels
- Age-related changes in rate of recovery
How to you fix it?
It’s important to not just ignore Calcaneal bone stress issues, or to just quit the activity that’s causing it. Even though that activity has lead to bone stress issues, it’s probably a vital ingredient in your long term health.
The first step is to confirm the diagnosis – that may be done clinically in most cases (ie. in the doctor/Physio’s rooms without the need for further testing).
Then you need to identify the cause of the injury in your case – the lists above can provide some ideas. If it’s nothing obvious (eg. your training volumes have been stable), it’s worth getting blood tests to clear any underlying blood or hormone issues.
From here, you need to start your rehab plan. This should consist of home exercises for strength training (which stimulates bone growth) and some level of cardio exercise if it’s tolerated well. If you can’t walk without pain, think about using a rower or exercise bike instead.
If you need some ideas about the right strength training program for a Calcaneal bone stress injury, check out our strength program for anyone in a boot or unable to take weight through their foot/ankle.
Restarting the causal activity, such as returning to running, can be tricky. Expect a few false starts when you seem to be going well but it flares up. It’s a slow moving condition so getting the right level of training during your recovery isn’t easy.
Myths about Calcaneal bone stress
If anti-inflammatory meds take away virtually all your pain, it’s actually a bad sign! Unlike most musculoskeletal conditions, bone stress symptoms disappear completely with meds like Nurofen or Voltaren so this points to a likely bone stress injury.
While anti-inflammatory meds tend to take away the symptoms temporarily, they reduce the bone’s ability to repair itself, worsening the condition and making stress fracture more likely.
Heel striking during running
Heel striking while running is NOT associated with increased bone loading on the heel. Overstriding and fast downhill running are both risk factors though.
Complete rest isn’t required for the early stages of bone stress injuries.
Reducing the volume of weight bearing activity (eg. running half the distance) is sufficient if you can complete it without increasing the pain.
Switching to non-impact forms of exercise, including strength exercises, using a rower or exercise bike, is worthwhile to maintain strength and fitness while reducing other forms of activity.
What other conditions can cause similar pain?
If it loosens up after some walking, it might be Plantarfasciitis.
If it’s worse in the morning but it’s not Plantarfasciitis, it could be a Subtalar Joint Irritation.
If it happened after walking on rocky ground or in old shoes, and it has only been a few days, it might just be a bruised heel pad.