title: Landing biomechanics in participants with different static lower extremity alignment profiles.
abstract: BACKGROUND
  Whereas static lower extremity alignment (LEA) has been identified as a risk factor for anterior cruciate ligament injury, little is known about its influence on joint motion and moments commonly associated with anterior cruciate ligament injury.
  
  
  OBJECTIVE
  To cluster participants according to combinations of LEA variables and compare these clusters in hip- and knee-joint kinematics and kinetics during the landing phase of a drop-jump task.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  A total of 141 participants (50 men: age = 22.2 ± 2.8 years, height = 177.9 ± 9.3 cm, weight = 80.9 ± 13.3 kg; 91 women: age = 21.2 ± 2.6 years, height = 163.9 ± 6.6 cm, weight = 61.1 ± 8.7 kg).
  
  
  METHODS
  Static LEA included pelvic angle, femoral anteversion, quadriceps angle, tibiofemoral angle, genu recurvatum, tibial torsion, and navicular drop. Cluster analysis grouped participants according to their static LEA profiles, and these groups were compared on their hip- and knee-joint kinematics and external moments during the landing phase of a double-legged drop jump.
  
  
  RESULTS
  Three distinct clusters (C1-C3) were identified based on their static LEAs. Participants in clusters characterized with static internally rotated hip and valgus knee posture (C1) and externally rotated knee and valgus knee posture (C3) alignments demonstrated greater knee-valgus motion and smaller hip-flexion moments than the cluster with more neutral static alignment (C2). Participants in C1 also experienced greater hip internal-rotation and knee external-rotation moments than those in C2 and C3.
  
  
  CONCLUSIONS
  Static LEA clusters that are positioned anatomically with a more rotated and valgus knee posture experienced greater dynamic valgus along with hip and knee moments during landing. Whereas static LEA contributes to differences in hip and knee rotational moments, sex may influence the differences in frontal-plane knee kinematics and sagittal-plane hip moments.
authors: Department of Athletic Training, High Point University, NC;
authors: Anh-Dung
authors: AD
authors: Nguyen
authors: Sandra J
authors: SJ
authors: Shultz
authors: Randy J
authors: RJ
authors: Schmitz
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D007719:Knee Joint / Q000502:physiology*; D035002:Lower Extremity / Q000502:physiology / Q000503:physiopathology; D008297:Male; D011187:Posture / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012307:Risk Factors; D012399:Rotation; D012737:Sex Factors
keywords: anatomical alignment; anterior cruciate ligament injury risk factors; lower extremity posture