title: The epidemiology of boys' youth lacrosse injuries in the 2015 season.
abstract: BACKGROUND
  Participation in boys' youth lacrosse has dramatically increased in recent years. Yet, research on the incidence of youth lacrosse injuries is limited. This study describes the epidemiology of boys' youth lacrosse injuries.
  
  
  RESULTS
  Aggregate injury and exposure data was collected from 550 boys' youth lacrosse players (aged 9-15 years) from eight leagues in four states. Injury frequencies and rates with 95 % confidence intervals (CI) were calculated. Rate ratios (RR) accounting for clustering within league compared game and practice injury rates. During the 2015 season, 155 injuries were reported for a rate of 12.98/1000AE (95 % CI:10.93-15.02). Most injuries occurred during games (60.0 %), resulted in time loss <24 h (83.9 %), and were in the U13/U15 divisions (69.0 %). Most injuries were to the lower extremity (45.2 %), and diagnosed as contusions (51.6 %). Ten concussions (6.5 %) were reported, with seven occurring in the U13/U15 divisions. All injuries resulting in time loss ≥24 h in the U9/U11 divisions were concussions. Most injuries were due to equipment contact, particularly stick contact (35.5 %) and ball contact (14.2 %). Injury rates were higher in games than practices overall (RR = 2.90; 95 % CI:1.81-4.89), and for concussions only (RR = 4.51; 95 % CI:1.89-11.03). Between the U9/U11 and U13/U15 divisions, the overall-injury rate was higher in U9/U11 (RR = 1.23; 95 % CI:1.05-1.44).
  
  
  CONCLUSIONS
  Our boys' youth lacrosse injury rate was higher than those previously reported, but may be more precise given the larger sample. The large proportion of equipment contact injuries demonstrate the need to adopt currently available coaching instruction and age-appropriate US Lacrosse rules that could better protect youth players.
authors.affiliation: Datalys Center for Sports Injury Research and Prevention, 401 W. Michigan St., Suite 500, Indianapolis, IN, 46202, USA. zkerr@datalyscenter.org.
authors.forename: Zachary Y
authors.initials: ZY
authors.lastname: Kerr
authors.affiliation: George Mason University, Sports Medicine Assessment, Research & Testing (SMART) Laboratory, 10900 University Blvd. MS 4E5, Manassas, VA, 20110, USA.
authors.forename: Shane V
authors.initials: SV
authors.lastname: Caswell
authors.affiliation: MedStar Sports Medicine Research Center, 201 E. University Parkway, 764 Bauernschmidt Bldg, Baltimore, MD, 21218, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Lincoln
authors.affiliation: Datalys Center for Sports Injury Research and Prevention, 401 W. Michigan St., Suite 500, Indianapolis, IN, 46202, USA.
authors.forename: Aristarque
authors.initials: A
authors.lastname: Djoko
authors.affiliation: Datalys Center for Sports Injury Research and Prevention, 401 W. Michigan St., Suite 500, Indianapolis, IN, 46202, USA.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Dompier
keywords: Epidemiology; Youth sports