title: Landing Error Scoring System Differences Between Single-Sport and Multi-Sport Female High School-Aged Athletes.
abstract: BACKGROUND
  Single-sport specialization (SSS) is becoming more prevalent in youth athletes. Deficits in functional movement have been shown to predispose athletes to injury. It is unclear whether a link exists between SSS and the development of functional movement deficits that predispose SSS athletes to an increased risk of knee injury.
  
  
  OBJECTIVE
  To determine whether functional movement deficits exist in SSS athletes compared with multi-sport (M-S) athletes.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Soccer practice fields.
  
  
  METHODS
  A total of 40 (21 SSS [age = 15.05 ± 1.2 years], 19 M-S [age = 15.32 ± 1.2 years]) female high school athlete volunteers were recruited through local soccer clubs. All SSS athletes played soccer.
  
  
  METHODS
  Participants were grouped into 2 categories: SSS and M-S. All participants completed 3 trials of the standard Landing Error Scoring System (LESS) jump-landing task. They performed a double-legged jump from a 30-cm platform, landing on a rubber mat at a distance of half their body height. Upon landing, participants immediately performed a maximal vertical jump.
  
  
  METHODS
  Values were assigned to each trial using the LESS scoring criteria. We averaged the 3 scored trials and then used a Mann-Whitney U test to test for differences between groups. Participant scores from the jump-landing assessment for each group were also placed into the 4 defined LESS categories for group comparison using a Pearson χ(2) test. The α level was set a priori at .05.
  
  
  RESULTS
  Mean scores were 6.84 ± 1.81 for the SSS group and 6.07 ± 1.93 for the M-S group. We observed no differences between groups (z = -1.44, P = .15). A Pearson χ(2) analysis revealed that the proportions of athletes classified as having excellent, good, moderate, or poor LESS scores were not different between the SSS and M-S groups ([Formula: see text] = 1.999, P = .57).
  
  
  CONCLUSIONS
  Participation in soccer alone compared with multiple sports did not affect LESS scores in adolescent female soccer players. However, the LESS scores indicated that most female adolescent athletes may be at an increased risk for knee injury, regardless of the number of sports played.
authors.affiliation: Department of Exercise and Sport Science, University of Utah, Salt Lake City.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Beese
authors.affiliation: Department of Family and Preventive Medicine, University of Utah, Salt Lake City.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Joy
authors.affiliation: Department of Athletics, Southern Oregon University, Ashland.
authors.forename: Craig L
authors.initials: CL
authors.lastname: Switzler
authors.affiliation: Department of Exercise and Sport Science, University of Utah, Salt Lake City.
authors.forename: Charlie A
authors.initials: CA
authors.lastname: Hicks-Little
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000503:physiopathology; D001696:Biomechanical Phenomena / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology*; D009068:Movement / Q000502:physiology; D012916:Soccer / Q000293:injuries / Q000502:physiology; D013177:Sports / Q000502:physiology*; D055815:Young Adult
keywords: injuries; knee; movement assessment