title: Hamstring-dominant strategy of the bone-patellar tendon-bone graft anterior cruciate ligament-reconstructed leg versus quadriceps-dominant strategy of the contralateral intact leg during high-intensity exercise in male athletes.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of anterior cruciate ligament (ACL) reconstruction on the quadriceps-dominant strategy as a parameter associated with the neuromuscular control of the knee joint.
  
  
  METHODS
  In this study 14 competitive soccer players who had undergone ACL reconstruction with bone-patellar tendon-bone autograft and 14 healthy competitive soccer players performed two 10-minute treadmill runs, 1 at moderate intensity and 1 at high intensity. Electromyographic recordings were acquired by use of a telemetric system at the third, fifth, seventh, and tenth minute of the runs from the vastus lateralis and the biceps femoris bilaterally. The dependent variable examined was the peak electromyographic amplitude during the stance phase. Analyses of variance were used to examine significant main effects and interactions.
  
  
  RESULTS
  Vastus lateralis electromyographic activity during high-intensity running increased for both the control leg and intact leg (F = 4.48, P < .01), whereas it remained unchanged for the reconstructed leg (P > .05). Biceps femoris electromyographic activity during high-intensity running increased for the reconstructed leg only compared with both the control leg (F = 3.03, P < .05) and intact leg (F = 3.36, P < .03).
  
  
  CONCLUSIONS
  There is no presence of the quadriceps-dominant strategy in ACL-reconstructed athletes during moderate-intensity exercise. During high-intensity exercise, the intact contralateral leg develops the quadriceps-dominant strategy whereas the reconstructed leg does not. The reconstructed leg instead increases biceps femoris activity, developing a "hamstring-dominant" strategy, and this "asymmetry" may theoretically be in favor of the reconstructed knee.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: Orthopaedic Sports Medicine Center, Department of Orthopaedic Surgery, University of Ioannina, Ioannina, Greece.
authors.forename: Kostas
authors.initials: K
authors.lastname: Patras
authors.forename: Franceska
authors.initials: F
authors.lastname: Zampeli
authors.forename: Stavros
authors.initials: S
authors.lastname: Ristanis
authors.forename: Elias
authors.initials: E
authors.lastname: Tsepis
authors.forename: Giorgos
authors.initials: G
authors.lastname: Ziogas
authors.forename: Nicholas
authors.initials: N
authors.lastname: Stergiou
authors.forename: Anastasios D
authors.initials: AD
authors.lastname: Georgoulis
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D056352:Athletes; D050376:Bone-Patellar Tendon-Bone Grafting; D004576:Electromyography; D005080:Exercise Test; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D012189:Retrospective Studies; D012916:Soccer / Q000293:injuries* / Q000502:physiology*; D055815:Young Adult