title: Jump-landing mechanics after anterior cruciate ligament reconstruction: a landing error scoring system study.
abstract: BACKGROUND
  The Landing Error Scoring System (LESS) is a clinical evaluation of jump-landing mechanics and may provide useful information in assisting with return-to-sport decisions in patients after anterior cruciate ligament reconstruction (ACLR). However, it is currently unknown how patients with ACLR perform on the LESS compared with healthy controls.
  
  
  OBJECTIVE
  To determine if the total LESS score differed between individuals with ACLR and healthy controls and to determine the types of errors that differ between groups.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  A total of 27 individuals with unilateral ACLR (age = 19.8 ± 1.8 years, height = 170 ± 5.5 cm, mass = 68.8 ± 11.9 kg) and 27 controls (age = 20.5 ± 1.7 years, height = 169 ± 8.4 cm, mass = 66.6 ± 9.0 kg) with no history of ACLR.
  
  
  METHODS
  Each participant completed 3 trials of a standardized jump-landing task.
  
  
  METHODS
  Each jump landing was assessed for specific postures using standardized LESS criteria by a blinded evaluator. Individual LESS items were summed to create a total LESS score. The dominant limb was assessed in the control group, and the reconstructed limb was assessed in the ACLR group.
  
  
  RESULTS
  The ACLR group had higher LESS scores compared with controls (ACLR: 6.7 ± 2.1 errors, control: 5.6 ± 1.5 errors, P = .04). Additionally, the ACLR group was more likely to err when landing with lateral trunk flexion (Fisher exact test, P = .002).
  
  
  CONCLUSIONS
  Individuals with ACLR had worse landing mechanics as measured by the LESS. Lateral trunk deviation may be related to quadriceps avoidance in the reconstructed limb or poor trunk neuromuscular control. The LESS is useful for evaluating landing errors in patients with ACLR and may help to identify areas of focus during rehabilitation and before return to sport.
authors.affiliation: Departments of Kinesiology and Orthopedics and Rehabilitation, University of Wisconsin, Madison.
authors.forename: David Robert
authors.initials: DR
authors.lastname: Bell
authors.forename: Mason D
authors.initials: MD
authors.lastname: Smith
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Pennuto
authors.forename: Mikel R
authors.initials: MR
authors.lastname: Stiffler
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Olson
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D001265:Athletic Injuries / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011184:Postoperative Period; D020127:Recovery of Function / Q000502:physiology*; D013177:Sports / Q000502:physiology*; D055815:Young Adult
keywords: core neuromuscular control; jump landing; musculoskeletal injuries; trunk