title: The Landing Error Scoring System (LESS) Is a valid and reliable clinical assessment tool of jump-landing biomechanics: The JUMP-ACL study.
abstract: BACKGROUND
  Anterior cruciate ligament injuries are common in athletes and have serious sequelae. A valid clinical tool that reliably identifies individuals at an increased risk for ACL injury would be highly useful for screening sports teams, because individuals identified as "high-risk" could then be provided with intensive prevention programs.
  
  
  OBJECTIVE
  A clinical screening tool (the Landing Error Scoring System, or LESS) will reliably identify subjects with potentially high-risk biomechanics.
  
  
  METHODS
  Cohort study (Diagnosis); Level of evidence, 2.
  
  
  METHODS
  A jump-landing-rebound task was used. Off-the-shelf camcorders recorded frontal and sagittal plane views of the subject performing the task. The LESS was scored from replay of this video. Three-dimensional lower extremity kinematics and kinetics were also collected and used as the gold standard against which the validity of the LESS was assessed. Three trials of the jump-landing task were collected for 2691 subjects. Kinematic and kinetic measures were compared across LESS score quartiles using 1-way analysis of variance; LESS quartiles were compared across genders using the chi-square test. The LESS scores from a subset of 50 subjects were rescored to determine intrarater and interrater reliability.
  
  
  RESULTS
  Subjects with high LESS scores (poor jump-landing technique) displayed significantly different lower extremity kinematics and kinetics compared with subjects with low LESS scores (excellent jump-landing technique). Women had higher (worse) LESS scores than men. Intrarater and interrater reliability of the LESS ranged from good to excellent.
  
  
  CONCLUSIONS
  The LESS is a valid and reliable tool for identifying potentially high-risk movement patterns during a jump-landing task.
authors.affiliation: Sports Medicine Research Laboratory, Chapel Hill, North Carolina, USA. dpadua@email.unc.edu
authors.forename: Darin A
authors.initials: DA
authors.lastname: Padua
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Marshall
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Boling
authors.forename: Charles A
authors.initials: CA
authors.lastname: Thigpen
authors.forename: William E
authors.initials: WE
authors.lastname: Garrett
authors.forename: Anthony I
authors.initials: AI
authors.lastname: Beutler
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000453:epidemiology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008403:Mass Screening; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment; D012727:Sex Characteristics; D014481:United States / Q000453:epidemiology