title: The immediate effects of open kinetic chain knee extensor exercise at different loads on knee anterior laxity in the uninjured.
abstract: BACKGROUND
  There is evidence that anterior laxity may be affected by knee extensor open kinetic chain (OKC) exercise with responses being load-dependent. The aim of this study is to evaluate the immediate and short-term changes in passive knee anterior laxity following a single session of OKC knee extensor exercise.
  
  
  METHODS
  Thirty two participants were randomly allocated to perform either high load (20 sets of 2 repetitions) or low load (2 sets of 20 repetitions) knee extensor OKC exercise with knee anterior laxity assessed before exercise, immediately after exercise and 45 and 90min after exercise with a KT-2000 arthrometer using a 133N force.
  
  
  RESULTS
  A significant effect of time was observed on knee laxity (p<0.001). However, a significant interaction of time and group was not found (p=0.54) and so the results presented here are for the combined (low and high load) group mean±standard deviation knee anterior laxity (mm) in the exercised leg: 7.2±2.2 (baseline), 8.2±2.3 (immediate post exercise, 14% change from baseline), 8.1±2.3 (45min post exercise, 12% change from baseline), and 7.7±2.2/0.29 (6.9) (90min post exercise, 7% change from baseline).
  
  
  CONCLUSIONS
  OKC knee extensor exercise at high loads and low loads causes an immediate increase in knee laxity that begins to decrease within 90min.
authors.affiliation: British School of Osteopathy, 275 Borough High Street, London, SE1 1JE, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Nicholettos
authors.forename: Massimo G
authors.initials: MG
authors.lastname: Barcellona
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Morrissey
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016118:Anterior Cruciate Ligament / Q000502:physiology*; D053587:Arthrometry, Articular / Q000379:methods; D001696:Biomechanical Phenomena; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D055070:Resistance Training / Q000379:methods*