Stress Fractures In Teenage Female Runners

Icing the shin

The Singapore National School's competitions are usually held between March and late May every year since 2009. And it's that time of the year again where we see many patients in our clinics with shin splints. Mostly adolescent and teenage girls and the occasional boy.

Why are girls more susceptible to shin splints and stress fractures? Well, some new data shows that if teenage female athletes don't eat enough to support their training, there will be complications regarding their subsequent training and health.

The study tracked 323 female athletes at Stanford University in 16 different sports including cross country running. Bone scans and questionnaires were used to assess the runners based on the components of the "female athlete triad" consisting of "low energy availability, with or without disordered eating, menstrual dysfunction and low bone mineral density. "

Risk status were calculated based on an article published in the British Journal of Sports Medicine  in 2014. Have a look at Figure 4 in the article if you're keen to know more about the calculations.

Looking only at the cross country runners (47 runners) data, half the runners were classified as low risk, and three of those later developed stress fractures.

Sixteen of the runners had moderate risk and 50 percent of these developed stress fractures within a year. These girls were about four times as likely to get injured compared to the low risk group.

Seven runners were in the high risk group and five of them developed stress fractures. They were nearly six times as likely as the low risk group to get injured.

Well, if you're thinking like me, not so good news for the girls if you're a runner and in the moderate to high risk group.

The researchers suggested the following guidelines for female athletes in the moderate to high risk group. The athletes need to ensure they're getting enough calories to support their training along with calcium and Vitamin D. Their menstrual function, bone health and nutrition needs to be monitored on an ongoing basis.

Higher risk athletes may have to consider using low impact cross training more often in their weekly routine. Good sleep and recovery are important too.

Stress fractures occurred mostly in the foot for the low risk athletes, probably as a consequence of biomechanics and jumping sports (due to higher forces).

In the higher risk categories, many of the stress fractures were in the sacrum, pelvis and femoral neck (where the bones tend to be softer). These areas may be due to weakened bone rather than biomechanical forces.

So all the doctors, physiotherapists, physical education teachers, coaches, heads of departments and administrators in charge of female teenage athletes reading this post, please take note.

Reference

Tenforde AS, Carlson Jl et al (2017). Association Of The Female Athlete Triad Risk Assessment Stratification To The Development Of Bone Stress Injuries In Collegiate Athletes. AJSM. 45(2): 302-310. DOI: 10.1177/0363546516676262.