New Data Reinforce Dangers of Sports Specialization

The numbers don’t lie.

New data is pointing to higher rates of injury from organized sports. Indeed, when compared to unorganized play the conclusion is clear. Get back to the old-fashioned playground to reduce injury rates.

An estimated 27 million U.S. youths between the ages of 6 and 18 participate in team sports and 60 million participate in some form of organized athletics. And many of these youth athletes are picking a main sport to focus on, despite data showing that sport specialization is an independent risk factor for injury.

The American Academy of Orthopaedic Surgeons (AAOS) and the American Orthopaedic Society for Sports Medicine (AOSSM) recently presented new study findings that explain the risks associated with youth sports specialization during a recent media webcast, “Fall Forecast: Settling the Youth Sports Safety Score” that took place at AAOS in its Orthopaedic Learning Center.

“Overuse injuries in children can have a lifetime effect on their game and quality of life,” event moderator Charles Bush-Joseph, MD, immediate past president of AOSSM, professor at Rush University Medical Center and associate director of the Rush Orthopaedic Sports Medicine Fellowship Program said during the broadcast.

“As more athletes under the age of 12 focus on just one sport and year-round training, coaches, parents and athletes need to encourage youth to think about participating in [a] variety of activities to prevent injuries. While sports participation has many benefits, including the development of strong bones and muscles, children who do specialize are often more likely to develop overuse injuries because of their repetitive movements, are stressed and may even consider quitting a sport and losing the benefits.”

Sex-Based Differences

The first new study findings presented during the webcast came from “Sex Based Differences in Common Sports Injuries” which was published in the July issue of the Journal of the American Academy of Orthopaedic Surgeons.

Elizabeth Matzkin, M.D., AAOS board member-at-large, chief of Women’s Sports Medicine and director of the Sports Medicine Fellowship at Brigham and Women’s Hospital, assistant professor of Orthopaedic Surgery at Harvard Medical School and Cordelia Carter, M.D., director of the NYU-Langone Health Women’s Sports Center and program director, Pediatric Sports Medicine at Hassenfeld Children’s Hospitals, lead authors of the review article, discussed the different risk factors for sport-related injuries male and female athletes experience particularly at the youth level.

Their article specifically looked at stress fracture, anterior cruciate ligament (ACL) tear, shoulder instability, concussion and femoroacetabular (hip) impingement. They found that females have a higher risk of stress fracture, secondary to a relative energy deficiency in sport compared to their male counterparts. Although the absolute number of ACL injuries per year is higher in male youth athletes, females have a two to eight times increased risk when playing similar sports.

In addition, females are less likely to return to sports after ACL injury. Research has also shown that in sports such as soccer, basketball and lacrosse, female athletes also have a higher incidence of concussion than their male counterparts.

According to Carter, “Anatomic and physiological characteristics such as skeletal structure, muscle mass, ligament flexibility and hormone levels differ between the sexes and may contribute to variations in injury risk.”

For example, she said, one possible reason for higher concussion rates among female athletes is less muscle mass in the neck which could offer less protection from head snaps and concussions. Symptom complaints are often different based on sex as well.

She said, “The best way to avoid or treat a sports-related injury in a male may be different for a female. Understanding the sex-based differences can help orthopaedic surgeons be better equipped to care for patients with these injuries and improve their treatment outcomes.”

Matzkin also highlighted the concerns over the Female Athlete Triad (FAT)/Relative Energy Deficit in Sport (RED-S). The Female Athlete Triad is a syndrome resulting from the combination of eating disorders (or low energy availability), amenorrhoea/oligomenorrhea and decreased bone mineral density (osteoporosis and osteopenia).

She explained that about 20 years after Title IX, which really opened the doors for female athletes, a group of physicians started to notice this triad of symptoms in female athletes that come in to be treated for stress fractures.

According to statistics she shared, about 36% of high school female athletes have low energy availability and 54% have menstrual dysfunction. Low energy availability is highest in ballet dancers and endurance athletes.

Matzkin added that 90% of our bone mineral density (BMD) is accrued by the age of 20 so these years are crucial when it comes to bone growth. A normal female gains 2% bone mass per year while an amenorrheic female loses 2% bone mass per year. And if they don’t have adequate BMD accrued, they will struggle with osteoporosis and stress fractures later in life.

The concern, Matzkin said, is that these stress fractures can be prevented so we need to ask our female athletes about nutrition and their menstruation, if they are of age, and we need to educate our parents, our athletes and our athletic trainers, coaches and everyone involved in our female athlete’s care.

Recently there has been a call to rename it to Relative Energy Deficit in Sport to include the effects of low energy availability and decreased bone mineral density on male athletes as well.

The Money Problem

More money, more problems? The second set of new data that was revealed during the webcast suggests a crucial role socioeconomic factors may play in overuse injuries.

The study, “Socioeconomic Factors for Sports Specialization and Injury in Young Athletes” was published in the July issue of Sports Health: A Multidisciplinary Approach.

Lead author, Neeru Jayanthi, M,D,, associate professor, Orthopedics and Family Medicine, Emory University School of Medicine, director, Emory Sports Medicine Research and Education, director, Emory’s Tennis Medicine Program and colleagues enrolled injured athletes aged 7 to 18 from two hospital-based sports medicine clinics in the Chicago area and compared them with uninjured athletes undergoing sports physicals between 2010 and 2013.

Overall, nearly 1,200 athletes were evaluated using training and injury surveys and electronic medical records to determine injury type.

According to the data they collected, 96% of the athletes had satisfactory socioeconomic (SES) data. Compared with low-SES athletes, high-SES athletes reported more hours per week spent playing organized sports (11.2 ± 6.0 vs 10.0 ± 6.5; p = 0.02), trained more months per year in their main sport (9.7 ± 3.1 vs. 7.6 ± 3.7; p < 0.01), were more often highly specialized (38.9% vs. 16.6%; p < 0.01), and had increased participation in individual sports (64.8% vs 40.0%; p < 0.01).

In addition, they found that the proportion of athletes with a greater than 2:1 ratio of weekly hours in organized sports to free play increased with SES and the odds of reporting a serious overuse injury increased with SES (OR, 1.5; p < 0.01).

Jayanthi said, “High socioeconomic status (SES) athletes reported more serious overuse injuries than low SES athletes, potentially due to higher rates of sports specialization, more weekly hours in organized sports, less frequent opportunities for free play, and greater participation in individual sports.”

“We think it is possible that injury risk happens not just from how much you play, but rather how you spend that time. Unorganized free play may potentially be protective of overuse injury. We believe that this allows an environment where the child can be self-directed.”

According to Jayanthi, prior research defined specialization to be intense year-round and more than eight months training in a single, main sport at the exclusion of others; and the risk that comes from that level of specialization participation.

Prior studies, he said, also suggest that adolescent females may be at highest risk for overuse injuries, especially in individual sports like tennis and dance.

The OneSport Injury Campaign

The AAOS and AOSSM hope their joint OneSport Injury youth sports specialization campaign, an outdoor public service campaign featuring a female soccer player and a male baseball player with the headline, “The OneSport Injury: Doctors Can Treat Them. Parents and Coaches Can Prevent Them” will help them share important data like this with more youth athletes and the people who take care of them.

“Immature bones, insufficient rest after injury, and poor training and conditioning can contribute to overuse injuries, Matzkin said during the webcast. “We know that overuse injuries account for half of all sports injuries in middle school and high school. Although we can treat most youth injuries, they can have consequences later in life, so it is vital to reduce or prevent incidence now and avoid the onset of chronic conditions. Equally important is nutrition as it is vital to proper bone health.”

Matzkin told OTW that orthopedic physicians and surgeons don’t always have time to have these types of discussion during patient appointments, so it is important to have resources to point them to.

She added, “We want kids to play sports but it becomes a fine line between beneficial and detrimental. We need to encourage kids that they don’t have to pick just one sport. Not only are they at higher risk of injury, they will also lose the long-term benefits of sports when they burn out or can’t go back because of injury.”

The AAOs and AOSSM encourage you to direct your youth athletes and their families to https://orthoinfo.aaos.org/en/staying-healthy/onesportinjury/.