title: Relationship of anterior knee laxity to knee translations during drop landings: a bi-plane fluoroscopy study.
abstract: OBJECTIVE
  Passive anterior knee laxity has been linked to non-contact ACL injury risk. High deceleration movements have been implicated in the non-contact ACL injury mechanism, and evidence suggests that greater anterior tibial translations (ATT) may occur in healthy knees that are lax compared to a tight knee. The purpose of this study was to determine the relationship between anterior knee laxity scores and ATT during drop landings using biplane fluoroscopy.
  
  
  METHODS
  Sixteen healthy adults (10 women; 6 men) performed stiff drop landings (40 cm) while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak and excursions for rotations and translations were calculated and regression analysis used to determine the 6DoF kinematic relationships with KT1000 scores with peak ATT occurring during the landing.
  
  
  RESULTS
  KT1000 values were (+) correlated with peak ATT values for group (r = 0.89; P < 0.0001) and both genders (males, r = 0.97; P = 0.0003; females, r = 0.93; P = < 0.0001). Regression analysis yielded a significant linear fit for the group (r (2) = 0.80; Y (ATT-group) = - 0.516 + 1.2 × X (KT1000-group)) and for each gender (females: r(2) = 0.86; Y (ATT-females) = 0.074 + 1.2 × X (KT1000-females) and males: r (2) = 0.94; Y (ATT-males) = - 0.79 + 1.2 × X (KT1000-males)).
  
  
  CONCLUSIONS
  A strong relationship was observed between passive anterior knee laxity measured via KT1000 and peak ATT experienced during dynamic activity in otherwise healthy persons performing a stiff drop-landing motion.
authors.affiliation: School of Kinesiology and Recreation, Illinois State University, Normal, IL, USA. mtorry@ilstu.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Torry
authors.forename: C
authors.initials: C
authors.lastname: Myers
authors.forename: W W
authors.initials: WW
authors.lastname: Pennington
authors.forename: K B
authors.initials: KB
authors.lastname: Shelburne
authors.forename: J P
authors.initials: JP
authors.lastname: Krong
authors.forename: J E
authors.initials: JE
authors.lastname: Giphart
authors.forename: J R
authors.initials: JR
authors.lastname: Steadman
authors.forename: Savio L-Y
authors.initials: SL
authors.lastname: Woo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007718:Knee Injuries / Q000503:physiopathology; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008953:Models, Anatomic; D009068:Movement; D010779:Photofluorography / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012494:Sampling Studies; D013977:Tibia / Q000502:physiology*; D016474:Weight-Bearing; D055815:Young Adult