title: Differences in the movement pattern of a forward lunge in two types of anterior cruciate ligament deficient patients: copers and non-copers.
abstract: OBJECTIVE
  To determine whether differences in the knee joint movement pattern of a forward lunge could be quantified in healthy subjects and in anterior cruciate ligament deficient subjects who were able to return to the same activity level as before their injury (copers) and in those who were not (non-copers).
  
  
  METHODS
  The movement patterns of the injured leg of the coper and non-coper anterior cruciate ligament deficient subjects and the right leg of the control subjects were compared statistically.
  
  
  BACKGROUND
  The forward lunge seems to be a less stressful test than the commonly used one-legged hop test, which makes it a possible tool for evaluating and comparing the functional performance of non-copers and copers.
  
  
  METHODS
  The movement pattern of a forward lunge was analysed by using a two-dimensional inverse dynamics method. The electromyographic activity of the quadriceps and hamstring muscles were recorded.
  
  
  RESULTS
  The non-copers moved more slowly and loaded the knee joint less than the copers and controls. The copers moved more slowly during the knee flexion phase but as fast as the controls during the knee extension. The EMG results suggest that the copers stabilized their knee joint by increasing the co-contraction of the hamstrings during the extension phase.
  
  
  CONCLUSIONS
  Differences between the three groups' movement patterns could be quantified. The forward lunge test seems appropriate to discriminate between the knee function in coper and non-coper anterior cruciate ligament deficient subjects.
  
  
  CONCLUSIONS
  Information about the performance of movements, which significantly load the knee joint in coper and non-coper anterior cruciate ligament deficient patients may contribute to a better understanding of dynamic knee joint stabilization, which is relevant in relation to the development of rehabilitation strategies.
authors.affiliation: Institute of Medical Anatomy & Institute of Medical Physiology, Section C, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark. t.alkjaer@mai.ku.dk
authors.forename: Tine
authors.initials: T
authors.lastname: Alkjaer
authors.forename: Erik B
authors.initials: EB
authors.lastname: Simonsen
authors.forename: S Peter
authors.initials: SP
authors.lastname: Peter Magnusson
authors.forename: Henrik
authors.initials: H
authors.lastname: Aagaard
authors.forename: Poul
authors.initials: P
authors.lastname: Dyhre-Poulsen
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000704:Analysis of Variance; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D004576:Electromyography; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D009068:Movement / Q000502:physiology*