How To Know If You Have A Bone Stress Injury (Stress Fracture).

Bone stress injuries (BSIs) are common among active individuals, especially runners and athletes, but their causes and diagnosis can be complex. While many assume that BSIs result simply from excessive running or high-impact activities, the reality is that these injuries are multi-faceted, resulting from cumulative load and various risk factors. In this blog post, we’ll explore what BSIs are, how they’re diagnosed, and the factors that contribute to their occurrence.

What is a Bone Stress Injury?

A bone stress injury is a spectrum of conditions that range from mild bone irritation to complete fractures. These injuries develop when the bone’s capacity to adapt to physical stress is exceeded. Unlike acute fractures from a single incident, BSIs develop gradually due to repeated strain on the bone.

How Bones Adapt.

Bone is a dynamic tissue that remodels itself in response to stress. When we exercise, the bone tissue experiences micro-damage, which triggers the body to repair and strengthen the bone. This process is known as bone remodelling and involves two key activities:

1. Osteoblasts (bone-building cells) create new bone tissue.

2. Osteoclasts (bone-breaking cells) remove bone tissue.

If the stress applied to the bone is too intense or frequent, the bone’s repair process cannot keep up, and this results in a bone stress injury. This failure of adaptation is more likely to happen under certain conditions, such as sudden increases in training loads, low energy availability, or compromised hormonal health.

How To Diagnosis A Bone Stress Injury.

Diagnosing BSIs requires more than just attributing pain to excessive training. Factors such as loading patterns, nutrition, footwear, and training intensity all play a role. When diagnosing BSIs, we look for specific patterns and conduct thorough assessments to identify contributing factors. Changes in training load, intensity, or type of activity can increase the risk of BSI. For instance, athletes switching from cushioned footwear to minimal shoes or incorporating speed work may place added stress on their bones.

BSI diagnosis is not as simple as identifying a load increase. For instance, BSIs are sometimes seen in individuals without significant changes in training. This points to a multi-factorial nature involving muscle forces, structural foot alignment, and even genetics.

Diagnosing BSIs involves careful examination and the consideration of various indicators:

1. History and Symptoms

The patient’s history is crucial, especially any prior BSIs. Symptoms often include pain that worsens with running or even walking, although some cases report warming up reduces pain, making diagnosis less straightforward.

2. Hop Test

Specifically for the foot, the hop test can be very effective. In the clinic, clients are asked to hop, which activates the calf and tests the load on bones such as the metatarsals. Increased pain during this test may indicate a BSI.

Hop testing can aid in the diagnosis of a bone stress injury. Podiatrist Albury. 

3. Palpation

Palpation helps identify specific zones of tenderness, such as the metatarsals or tibia. For example, pain along the top aspect of a metatarsal is a common area for pain with a BSI. Other areas such as the Navicular, we assess the ‘N Spot’ - an area that can correlate to a BSI. Palpation isn’t everything, it helps formulate key presentations when looking too diagnose.

4. Imaging

MRI and / or CT imaging is what allows BSIs to be confirmed, and graded appropriately. This is helpful as it can dictate the required offloading time, and if a further referral is required pending the severity of the injury.

Risk Factors for Bone Stress Injuries

Certain factors increase the likelihood of developing a BSI, including:

1. Low Energy Availability

When the body lacks sufficient energy from food to support both its basic functions and high activity levels, it prioritises essential survival functions over non-essential ones, like bone health. This energy shortfall can compromise bone strength and increase the risk of injury. Low energy availability can cause hormonal changes, particularly in females, where irregularities in the menstrual cycle are a common indicator. For males, signs can include reduced facial hair growth or reduced libido.

2. Hormonal Changes

Hormones play a vital role in maintaining bone density. Disruptions due to low energy availability or high training loads can reduce bone strength, increasing susceptibility to BSI. In females, menstrual irregularities can be an early warning sign of compromised bone health.

3. Genetic and Structural Factors

Genetics and bone structure also contribute to BSI risk. For example, some individuals may naturally have longer metatarsals, leading to higher forces on these bones. Previous injuries and family history also play a role, as does early specialisation in sports, which can place repetitive stress on specific bones from a young age.

Conclusion

Bone stress injuries can be challenging to diagnose due to the many factors that contribute to their development. By considering training load, energy availability, and unique anatomical factors, podiatrists can better assess and manage BSIs, helping athletes and active individuals return safely to their activities.

If you think you may have a BSI, reach out below!