Risks of Specialized Training and Growth for Injury in Young Athletes: A Prospective Cohort Study

Monday, October 28, 2013: 3:30 PM
Florida Ballroom A (Hyatt Regency Orlando, formerly the Peabody)
Neeru Jayanthi, MD1, Cynthia LaBella, MD, FAAP2, Lara Dugas, PhD1, Erin R. Feller, BA1 and Brittany Patrick, MPH3, (1)Loyola Stritch School of Medicine, Maywood, IL, (2)Northwestern University's Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, (3)Orthopaedics, Lurie Children's Hospital, Chicago, IL

Purpose: To determine whether the degree of sports specialization, weekly training volumes, and growth rates are independent risk factors for injury in young athletes.


Methods and Study Design:  This multi-center prospective cohort study followed injured young athletes recruited from sports medicine clinics and uninjured athletes recruited during their sports physical at primary care clinics.  At baseline, all athletes were 8-18 years old and completed a survey reporting training volumes, degree of sports specialization, Tanner stage, and had height and weight measured.  This same data was collected from each participant at 6 month intervals for up to 3 years (2010-2012).

Results: There were 1206 participants (50.7% male) who evaluated at baseline while longitudinal follow up data collection is ongoing at time of submission.  There were 837 injured participants with a total of 859 unique injuries with 360 uninjured participants that served as controls.  Injured athletes were older than uninjured athletes (14.0 +/- 2.2 vs. 12.9 y/o +/-2.6, p<0.001), reported a higher average hours/week playing organized sports (11.3 +/- 6.9 vs. 9.4 +/-8.2 ;  p<0.001), and higher average hours/week in total (gym, free play, organized) sports activity (19.7 +/-9.8 vs 17.6 +/-10.3; , p<0.001).  Using a six point specialization score designed for this study, injured athletes had a significantly higher degree of specialization than uninjured athletes (3.3 +/- 1.6  vs. 2.7 +/- 1.6; OR 1.27, p<0.001), even after adjusting for hrs/week in total sports activity and age (p<0.001).  Injured athletes had similar annual calculated growth rate at baseline (4.75 vs 4.75 cm/yr).  Young athletes who participated in more total hours then age (p=0.004) and who participated in > 2 times organized sports then free play (p=0.004) were more likely to be injured.  Young athletes at risk for serious overuse injury also participate in more total hours then age and are more specialized. 

Conclusions: Injured young athletes are older and spend more total sports hours/week and in  hours/week of organized sports.  There is an independent risk of injury in athletes that are more specialized, even when accounting for hours/week of sports participation and age.  There is also a risk of injury and serious overuse when participating in more sports hours/week then age and all types of injury if participates in more then twice organized sports then free play hours.   There does not appear to be a relationship between growth rate and increased risk of injury in the baseline data.

Clinical Relevance: Determining the degree of sports specialization and weekly training volumes  may help pediatricians identify young athletes at higher risk for all type and serious overuse injury. 

Acknowledgements: 2 Consecutive American Medical Society for Sports Medicine Foundation Grant