title: Sport specialization's association with an increased risk of developing anterior knee pain in adolescent female athletes.
abstract: OBJECTIVE
  To determine if sport specialization increases the risk of anterior knee pain in adolescent female athletes.
  
  
  METHODS
  Retrospective cohort epidemiology study.
  
  
  METHODS
  Female basketball, soccer, and volleyball players (N = 546) were recruited from a single county public school district in Kentucky consisting of 5 middle schools and 4 high schools. A total of 357 multisport and 189 single-sport (66 basketball, 57 soccer, and 66 volleyball) athlete subjects were included due to their diagnosis of patellofemoral pain (PFP) on physical exam. Testing consisted of a standardized history and physician-administered physical examination to determine the presence of PFP. This study compared self-reported multisport athletes with sport-specialized athletes participating in only 1 sport. The sports-participation data were normalized by sport season, with each sport accounting for 1 season of exposure. Incidence rate ratios and 95% confidence intervals (CI) were calculated and used to determine significant differences between athletes who specialized in sport in early youth and multisport athletes.
  
  
  RESULTS
  Specialization in a single sport increased the relative risk of PFP incidence 1.5-fold (95% CI 1.0-2.2, P = .038) for cumulative PFP diagnoses. Specific diagnoses such as Sinding Larsen Johansson/ patellar tendinopathy (95% CI 1.5-10.1, P = .005) and Osgood Schlatter disease (95% CI 1.5-10.1, P = .005) demonstrated a 4-fold greater relative risk in single-sport compared with multisport athletes. Incidence of other specific PFP diagnoses such as fat pad, plica, trauma, pes anserine bursitis, and iliotibial-band tendonitis was not different between single-sport and multisport participants (P > .05).
  
  
  CONCLUSIONS
  Early sport specialization in female adolescents is associated with increased risk of anterior knee-pain disorders including PFP, Osgood Schlatter, Sinding Larsen-Johansson compared with multisport athletes.
authors.affiliation: Dept of Pediatric Orthopaedics and Sports Medicine, Phoenix Children's Hospital, Phoenix, AZ.
authors.forename: Randon
authors.initials: R
authors.lastname: Hall
authors.forename: Kim
authors.initials: K
authors.lastname: Barber Foss
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Hewett
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Myer
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000209:etiology*; D001490:Basketball / Q000293:injuries*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007629:Kentucky; D007718:Knee Injuries / Q000209:etiology*; D046788:Patellofemoral Pain Syndrome / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*; D054798:Volleyball / Q000293:injuries*