title: Effect of fatigue on landing performance assessed with the landing error scoring system (less) in patients after ACL reconstruction. A pilot study.
abstract: BACKGROUND
  Fatigue has been shown to affect performance of hop tests in patients after anterior cruciate ligament reconstruction (ACLR) compared to uninjured controls (CTRL). This may render the hop test less sensitive in detecting landing errors. The primary purpose of this study was to investigate the effect of lower extremity fatigue on landing performance assessed with the Landing Error Scoring System (LESS) in patients after ACLR compared to a CTRL group. It is plausible that fatigue would have an effect on confidence and risk appraisal in the ACLR group. The secondary purpose was to determine the relationship between psychological responses and LESS scores after fatigue.
  
  
  METHODS
  Twelve patients following ACLR (6 males, 6 females) who were tested at 10 ± 2.4 months after surgery participated in the current study and were compared to 10 subjects in the control group (5 males, 5 females). Subjects performed a jump-landing task and the landing was assessed using the Landing Error Scoring System (LESS) both before and after fatigue. Digital video camcorders recorded frontal and sagittal plane views of the subject performing the task. The LESS was scored using video replay. Psychological responses in the ACLR group were assessed with the ACL-RSI questionnaire.
  
  
  RESULTS
  Patients after ACLR had a median LESS of 6.5 which reflects a poor result (LESS >6) in the pre-fatigue condition compared to controls who had a LESS of 2.5 which is considered excellent (≤4). In the post-fatigue condition, median LESS in patients after ACLR increased to 7.0 whereas in the control group the LESS increased to 6.0 both of which reflect a poor result. The median increase in LESS was larger in the control (2.0) group compared to patients after ACLR (1.0) but the difference was not significant (p=0.165).
  
  
  CONCLUSIONS
  Patients after ACLR have higher LESS scores at baseline compared to a control group. Fatigue resulted in an increase in scores on the LESS in both groups.
  
  
  METHODS
  3b.
authors.affiliation: University of Groningen, University Medical Center Groningen. Center for Human Movement Sciences. Groningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Gokeler
authors.affiliation: FLYTTA Sports Physical Therapy. Groningen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Eppinga
authors.affiliation: University of Groningen, University Medical Center Groningen. Center for Rehabilitation. Groningen, The Netherlands.
authors.forename: P U
authors.initials: PU
authors.lastname: Dijkstra
authors.affiliation: University of Groningen, University Medical Center Groningen. Center for Human Movement Sciences. Groningen, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Welling
authors.affiliation: Department of Exercise and Sport Science. University of North Carolina. Chapel Hill, NC, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Padua
authors.affiliation: University of Groningen, University Medical Center Groningen. Center for Human Movement Sciences. Groningen, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Otten
authors.forename: A
authors.initials: A
authors.lastname: Benjaminse
keywords: Anterior cruciate ligament; fatigue; jump landing; psychology; return to sport