Spring may mean baseball and softball to many athletes and fans. Yet, the spring sport with the highest level of participation is track.
Unlike baseball and softball players who start playing at age 6 or younger, though, track participants at the junior high and high school levels are typically far newer to their sport. Unaccustomed to the training required then, novice runners are often victimized by overuse injuries, particularly to bone.
It would be easy to accept stress fractures as an unavoidable risk that comes with running track and, in the fall season, cross country. Other sports at risk include football, soccer, basketball and volleyball. However, a study published online in January in the medical journal Sports Health identified several modifiable factors that contribute to bony stress injury (BSI) in adolescent athletes.
The National High School Stress Fracture Registry consisted of 60 athletic trainers in 11 states who recorded stress fractures over a two-year period and completed a multiple-question survey for all 346 BSIs, asking about gender, medical history, diet, mental health, training regimen, sleep, equipment and facilities.
While stress fractures are possible in any bone, the vast majority in this study occurred in the leg or foot. Females are apparently at greater risk, suffering two-thirds of the studied fractures.
Meanwhile, similar data were collected from a healthy control group of high school athletes.
The differences between the two groups were telling.
Those with the stress fractures had an average body mass index (BMI) that was significantly lower than those in the control group.
While lower BMI might seem desirable for some athletes, runners especially, those who fail to consume necessary levels of nutrients, including calcium, jeopardize bone health. That is probably why those with stress fractures consumed significantly fewer dairy products per day than the healthy controls.
It takes more than calcium to make bones healthy. Everyone knows that weight training builds muscle, but it strengthens bones, too. Those with the stress fractures lifted weights once per week while the healthy group lifted more than twice weekly. More notably, fully 58% of the stress fracture group did not weight train at all.
A previous history of otherwise undiagnosed shin pain was found far more frequently among the BSI group.
Perhaps a more surprising risk factor was sleep. Those with stress fractures averaged 7.2 hours of sleep per night while the healthy group averaged 7.95 hours.
Even psychological stress was identified as a risk factor, with the stress fracture group reporting significantly higher levels.
Age and level of competition may also have played a role. The study authors found that while both groups had similar rates of participation at the varsity level, the BSI group was nearly a half year younger. The authors then suggested that perhaps those in the injured group had advanced too quickly. To support that suggestion, they cited a separate study that demonstrated advancing from high school to college was a risk factor for BSI due to increased intensity of training and competition.
Consequently, the study authors concluded, “Because of developmental differences in strength, size, ability, coordination, and bone strength between adolescents and adults, training variables suggested for adult athletes such as specialization, extended duration of practice, number of successive days of practice, and acceptable rest may not be appropriate for the adolescent population. Based on the findings from NHSSFR and the comparison of reported data with a healthy control group, significant targets for preventative strategies include the reduction of psychosocial stress, weight training, dairy intake, and appropriate sleep and rest.”
Also, when an athlete complains of shin pain, that complaint should not be ignored but instead prompt an evaluation by an athletic trainer and/or sports medicine physician.