title: Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects.
abstract: Previous studies mainly focused on muscles at the operated knee after anterior cruciate ligament reconstruction, less on muscles around other joints of the operated and non-operated leg. The aim of this study was to investigate muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects.
  
  
  
  Lower extremity muscle activation onset times of both legs of 20 fully returned to sport anterior cruciate ligament reconstructed subjects and 20 non-injured control subjects were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Analysis of covariance (ANCOVA) was used to evaluate differences between groups and differences between legs within both groups, while controlling for peak center of pressure velocity.
  
  
  
  Significantly delayed muscle activation onset times were found in the anterior cruciate ligament reconstructed group compared to the control group for gluteus maximus, gluteus medius, vastus medialis obliquus, medial hamstrings, lateral hamstrings and gastrocnemius in both eyes open and eyes closed conditions (P<.05). Within the anterior cruciate ligament reconstructed group, no significant different muscle activation onset times were found between the operated and non-operated leg (P>.05).
  
  
  
  Despite completion of rehabilitation and full return to sport, the anterior cruciate ligament reconstructed group showed neuromuscular control deficits that were not limited to the operated knee joint. Clinicians should focus on relearning multi-segmental anticipatory neuromuscular control strategies after anterior cruciate ligament reconstruction.
authors.affiliation: KU Leuven Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium. Electronic address: bart.dingenen@kuleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Dingenen
authors.affiliation: KU Leuven Department of Electrical Engineering, Faculty of Engineering Technology Services, Andreas Vesaliusstraat 13, 3000 Leuven, Belgium; KU Leuven Cardiovascular and Respiratory Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium. Electronic address: luc.janssens@kuleuven.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Janssens
authors.affiliation: Department of Orthopedic Surgery, AZ Herentals Hospital, Nederrij 133, 2200 Herentals, Belgium; Department of Orthopedics, University Hospitals Leuven, Campus Pellenberg, Leuven, Weligerveld 1, 3212 Pellenberg, Belgium. Electronic address: steven@kreutzfeldverein.be.
authors.forename: Steven
authors.initials: S
authors.lastname: Claes
authors.affiliation: Department of Orthopedics, University Hospitals Leuven, Campus Pellenberg, Leuven, Weligerveld 1, 3212 Pellenberg, Belgium. Electronic address: johan.bellemans@skynet.be.
authors.forename: Johan
authors.initials: J
authors.lastname: Bellemans
authors.affiliation: KU Leuven Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium.
authors.forename: Filip F
authors.initials: FF
authors.lastname: Staes
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000843:Ankle Joint / Q000502:physiology; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries / Q000534:rehabilitation / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007593:Joint Instability / Q000601:surgery; D007719:Knee Joint / Q000502:physiology*; D035002:Lower Extremity / Q000601:surgery; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D055815:Young Adult
keywords: Anterior cruciate ligament reconstruction; Injury prevention; Lower extremity; Neuromuscular control; Rehabilitation