title: Altered Peak Knee Valgus during Jump-Landing among Various Directions in Basketball and Volleyball Athletes.
abstract: OBJECTIVE
  Excessive knee valgus during landing tasks is a contributing factor to knee injuries. Most studies have examined lower extremity biomechanics during the forward direction of a jump-landing task. Athletes perform many movements in the air and land in multi-directions. Therefore, the purpose of this study was to assess the peak knee valgus angle (PKVA) during one leg jump-landing in various directions.
  
  
  METHODS
  Eighteen male basketball and volleyball athletes participated in the study. Participants performed one leg jump-landing tests from a 30 cm height platform in four directions. Knee valgus motion was measured using Vicon™ motion system. The data were analyzed with repeated measures ANOVA.
  
  
  RESULTS
  Direction significantly (P<0.001) influenced the PKVA during landing. Significantly higher PKVA was observed for the lateral (8.8°±4.7°) direction as compared to forward (5.8°±4.6°) direction (P<0.05). The PKVA in 30° diagonal (7.5°±4.6°) and 60° diagonal (7.7°±5.7°) directions was higher than in the forward direction (P<0.05).
  
  
  CONCLUSIONS
  One leg jump-landing in lateral and diagonal directions results in a higher PKVA compared to landing in a forward direction and could lead to a higher risk of knee injury.
authors.affiliation: Faculty of Physical Therapy, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Komsak
authors.initials: K
authors.lastname: Sinsurin
authors.affiliation: Faculty of Physical Therapy, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Roongtiwa
authors.initials: R
authors.lastname: Vachalathiti
authors.affiliation: Faculty of Physical Therapy, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Wattana
authors.initials: W
authors.lastname: Jalayondeja
authors.affiliation: College of Sports Science and Technology, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Weerawat
authors.initials: W
authors.lastname: Limroongreungrat
keywords: Basketball and Volleyball; Jump-Landing; Knee Valgus Angle; Risk of Knee Injury