Stress Injuries to the Tibia: A Video Interview

Sincere thanks to Matt Swift, DPT from Change Sports Physical Therapy Institute for creating this video on Stress Injuries to the Tibia with focus on symptoms, treatment, and prevention. 

Detective Work: 5 Culprits Causing Young Athlete's Bone Stress Injuries

As a sports medicine specialist, here 5 important factors that should be included in every evaluation of a bone stress injury:

1. Timing

• Early in a new activity (especially within the first 3 weeks), stepping up to a higher level (first weeks of high school or travel team), or increasing amount or intensity of workouts (double days or more difficult routines) all can lead to acute overload and bone stress injuries.
• Cumulative stresses from months of training are another frequent contributor to bone stress injury and can also reduce overall immunity. Tend to be very cautious with any local bone pain that comes up right after a major accomplishment (end of long season, finished lead role in major performance) and especially when a performer reports "I'm at the top of my game."
• Too much load, too fast of increasing load, or too long of sustained load 

2. Technique

• Inappropriate technique or attempts to modify mechanics can lead to bone overload. Examples include:
  • Longer stride with slower stride rate: evidence shows that a shorter stride and faster stride cadence may reduce overload on bones of the foot and lower leg in runners
  • Poor activation of gluteal muscles in the lower back/buttock region can place rotational forces on the thigh and shin regions
  • Gymnasts with poor stabilizing strength of upper back and shoulders may place undue forces and increase cumulative stress on the forearm bones
• Any under-rehabilitated past injury of any type can change technique and place abnormal forces on a particular bone or region of the body, increasing risk for stress injury. 
• Comprehensive review of technique and biomechanics, often involving coach insight, can be extremely helpful in addressing these issues.

3. Appropriate Energy Intake

• Insufficient caloric intake to meet training demands can lead to a decreased ability to repair/build bone structure. The International Olympic Committee published a recent paper outlining the concept of Relative Energy Deficiency in Sport that pertains to all athletes. 
• For female athletes, reviewing the elements of the Female Athlete Triad (includes absent/infrequent menstrual periods, disordered eating habits, and weaker bone structure) is absolutely essential to identify common and correctable causative factors for bone stress injury.
• A focused diet history combined with targeted physical and laboratory evaluation can be performed by a sports medicine specialist to provide greater insight.

4. Not enough rest

• Bone needs time to remodel after physical activity, thus insufficient rest can lead to a higher risk of stress injury. Acute (showcase events, tournaments, intense auditions) or chronic (playing on multiple teams, playing a single sport more than 8-9 months a year) cumulative stress is not ideal for allowing sufficient recovery time.
• The American Academy of Pediatrics Council on Sports Medicine and Fitness recommends taking at minimum one day off per week for acute recovery and limiting participation in a particular sport to no more than 8-9 months per year to allow longer-term recuperation.

5. Growth spurts

• A growing athlete often suffers from a lack of central upper back/shoulder and lower back/pelvic strength which causes the now longer arms and legs to have less control and coordination. Even with emerging increases in muscle strength, the immature developing bones are at an increased risk for injury.
• The entire body needs additional calories to foster growth, which might create a relative deficiency in caloric delivery to working bone and muscle, further increasing overload stress opportunities.

This blog post does not intend to diagnose or provide any management tips for a particular stress injury, or any other injury or illness. If you suspect a stress injury, please immediately contact a sports medicine specialist for appropriate evaluation and treatment recommendations. 

Overload injuries to bone are aptly called stress injuries as their often untimely presentation and unpredictable healing times can provoke high levels of emotional stress for patients and medical providers. While the actual diagnosis can require some detailed investigation, trying to identify root causes of stress injuries is a necessary detective game that can ultimately reduce the risk of future stress injuries and assess the overall bone health of the athlete.

Stress Fracture of the outer lining of tibia (shin bone) in a young dancer

A Simple Way to Understand the Types of Bone Stress Injuries in Athletes

Stress injuries to bones of athletes are often caused by relative overload, and in describing the spectrum of possible bone stress or overload injuries to patients, I often use the analogy of bending my pen while bored in class one day.

• If I just start trying to bend my pen, the pen doesn't bend much. This represents normal bone.
• As I continue to play with my pen, it does start to bend more. This represents a stress reaction where the bone is softer and less able to resist continued load. A stress reaction will create swelling (bone edema) on a Magnetic Resonance Imaging (MRI) study, but no true fracture line will be visible either on the MRI or plain x-ray study.
• If I'm really bored in class, or it's a longer class period, my continued attempts to bend the now even more weakened pen eventually may cause it to completely break on one side. This represents a stress fracture which is a progression of a stress reaction where a fracture line is seen on one cortex (outer lining of the bone) on either MRI or plain x-ray.
• Even more attempts to bend my pen may result in breaking it in half. This represents a complete fracture which is a progression of a stress fracture where the fracture line is now visible on both cortices (outer linings of the bone) on either MRI or plain x-ray.

Stress Fracture of Left Femoral Neck: This MRI picture shows a fracture line involving only one cortex (outer lining) of the femur (thigh bone) with bone swelling (edema) also present.

Look forward to an upcoming post on important things to consider after the diagnosis of a bone stress injury has been made.