Common Injury Sites
Although bone stress injuries and fractures are not as frequent as other injuries seen in our Melbourne sports chiropractic practice, they are prevalent in active individuals and athletes. Stress fractures and bone stress injuries are more common in the lower extremity and include the bones in the feet (metatarsals and navicular), the leg bones (tibia and fibula), the thigh bone (femur), sacrum (pelvis), pars (lumbar spine). They can also occur in other less common areas like the humerus and wrist in tennis players and baseball pitchers.
Stress Versus Insufficiency Bone Fractures
When bone starts to fail there are two primary reasons for it. In the first instance normal healthy bone begins to fail under abnormal stress loading which is called a “stress fracture”. In the second instance there is abnormal bone which fails under normal stress loading called an “insufficiency fracture”. Insufficiency fractures occur when there is something systemically wrong within the body, resulting in abnormal bone health.
Bone Remodeling
Understanding bone health and how bones remodel is key to understanding why bone stress injuries and fractures occur. Two important cells in bone remodelling are osteoclasts and osteoblasts. Osteoclasts are like the demolition team who come in and break down old bone which is called “bone resorption”. Osteoblasts are the builders who come in a lay down new bone once the osteoclasts have removed the old bone which is called “bone formation”. This process is called “bone turnover” and in exercise is it vitally important, as bone turnover allows new bone to form and adapt to the stress loads that exercise is placing on the bone, helping the bone to adapt and become stronger. The entire process takes approximately 3-4 weeks under ideal conditions.
In the case of bone stress injuries and fractures the ideal conditions for bone turnover are compromised which can include alterations in bone nutrition; low vit d, low energy availability; rapidly increased training load; impaired endocrine function. Changes in these conditions ultimately leads to an imbalance between osteoclast and osteoblast activity, resulting in bone tissue break down occurring at a faster rate than new bone tissue can be laid down.
Bone Tissue Breakdown
To understand how this bone tissue breakdown process impacts bone health we need to think of bone health as a continuum. At one end of that continuum there is healthy bone and at the other end there is a fractured bone. Bone health can slide backwards and forwards along this continuum depending on those variables which impact bone health as mentioned above.
Let’s use an example to illustrate how bone moves down this continuum. For simplicity we will assume nutrition and endocrine function are normal. We will use a runner who is new to running with no prior running experience. Let’s assume they have a half marathon they are training for in 8 weeks. Because they have only a short period of time before the race, they start running 5 days a week. As they start running the osteoclasts begin breakdowning old bone so that new bone can be laid down to strengthen the bone as it adapts to the new impact loads going through the bone as a result of running. The more running, the more osteoclast activity occurs however, the osteoblast activity takes time to lay down new bone so an imbalance in the process begins to occur.
Initially this leads to microtrauma in the bone which will present clinically as a focal (specific) area of tenderness over the bone, mostly noticeable on impact activities like running, jumping, hopping etc This is called “bone marrow edema”. The runner notes this as ‘training pains’ as they are new to running. As they continue to run 5 days a week, bone tissue breakdown continues, while new bone formation is unable to keep pace due to the rapid increase in loading and lack of rest days. The microtrauma persists and the bone continues to slide down the continuum through the 4 stages of bone marrow edema finally resulting in macrotrauma to the bone tissue, creating a fracture site.
Clinically, this can present similar to an acute fracture where an instant acute pain is felt, or there can be continuously worsening acute pain which becomes present with simple activities like walking or weight bearing. Both force the individual to stop exercising and usually seek treatment.
Bone Stresss Injuries and Fracture Treatment
The way sports chiropractor Dr. Shannon at The Shannon Clinic – Melbourne Chiropractic and Sports Care treats bone stress injuries and stress fractures is through a complete and thorough work up which routinely includes other clinicians. The key questions that need to be established are “why has this injury occurred?” and “is this a bone health related injury or a training load injury?”. Our workups often include:
- Looking at whether there is a prior history of bone injuries, as a prior stress fracture is a predictor of a future stress fracture injury.
- Assessing bone health – DEXA, MRI, Vit D (serum 25) and Calcium blood tests
- Assessing nutritional intake – energy availability
- Assessing endocrine function
- Assessing training load and volume
- Assessing for biomechanical imbalances/weaknesses
- Assessing for technique deficits
Fracture Healing Process
Once we have pertained the cause of the bone injury and have determined it is a training load injury and not a bone-related injury, we then move into treatment and education. Treatment to optimise bone health (nutritional and supplement support), strategies to allow the bone healing process to catch up, strengthening programs, education on training load management to mitigate the risk of reinjury, technique modification if required.
To book an appointment to have your bone pain assessed below and you will be in safe hands. Our sports chiropractic clinic is situated on Collins Street in the Melbourne CBD, opposite the City Square and Melbourne Town Hall.
