Stress fractures are a big problem in the distance world.  If a runner gets hurt, odds are good that it will be either IT Band Syndrome, plantar fasciosis, or a stress fracture of some kind.

A stress fracture is a partial fracture of a bone due to repetitive microtrauma.  Moreover, stress fractures occur when the frequency of microtrauma (stimulus) exceeds the rate of bone remodeling (adaptation).  Traditionally, stress fractures are divided into two distinct categories: fatigue or insufficiency fractures.  Fatigue fractures result from abnormal levels of stress applied to a healthy bone whereas insufficiency stress fractures result from stress upon an abnormal bone (osteopenia, etc).  While each has certain unique factors relating to its ontogeny, the  movement considerations are generally similar.  While both men and women are at risk, female athletes are at a 1.5-3.5x greater risk of stress fracture, possibly as a result of hormonal differences and decreased muscle CSA, among other things (Burnett, 1990; Markey, 1987).

In looking at the prevention of stress fractures, we must first understand what contributes to bone strength, damage, and remodeling.

A number of factors to be considered can be broken down into intrinsic and extrinsic factors that are either modifiable or non-modifiable.

Intrinsic factors include malalignment, dysfunctional gait patterns (hypopronation, hyperpronation), small tibia diameter, foot type (cavus, planus), muscle imbalance and fatigue, biochemical factors (nutrition, hormone flow), and neuromuscular control.  Extrinsic factors are generally considered to be training errors, environmental factors (running surface), and equipment errors (shoes, orthoses, etc).  Of all factors mentioned above, many are greatly modifiable.  In fact, many authors go as far as to say that fatigue fractures, and, to a large extent, insufficiency fractures are preventable if the right steps are taken (McBryde, 1975; Bennell, 1997; Dugan, 2007).

What are the necessary steps?

Modify what is modifiable and mitigate the unmodifiable.  This first step starts with identifying limitations in movement efficiency, motor control, and determining malalignments.  Additionally, identifying dysfunctional gait patterns, foot attitudes, and modifying biochemical risk factors with the help of a nutrition professional and intelligent programming of general strength exercises can go a long way.  For the coaches out there, you need to monitor loading levels, particularly big changes, understand the environment of both where runs occur and the environment in which the foot lives (footwear, orthoses).  Some arguments exist that support the idea that moving unshod may be a fine solution as stride length is generally reduced in the absence of cushioning, and reduced stride length by 10% reduces incidence of stress fracture occurrence even if it requires more loading cycles per unit distance (Edwards, 2009)

While you will be unable to modify things like tibial diameter relative to body size, taking care of what can be changed will go a long way at mitigating risk and keeping athletes healthy.  Remember the words of Bill Bowerman, “an injured athlete is worthless.”  I’d also add that a coach who leads athletes to injury without an effort to identify and mitigate risks is worthless.

In the coming days I’ll share a few ideas concerning the performance coach’s role in preventing and assisting in return to competition with respect to stress fractures.

Have an excellent day!

Best regards,

Carson Boddicker

Boddicker Performance