title: Jumping performance differences among elite professional handball players with or without previous ACL reconstruction.
abstract: OBJECTIVE
  Handball is one of the most challenging sports for the knee joint. Persistent strength and jumping capacity alterations may be observed among athletes who have suffered anterior cruciate ligament (ACL) injury. The aim of this study was to examine unilateral and bilateral jumping ability differences between previously ACL-reconstructed rehabilitated elite handball athletes and sex, age and uninjured sport activity level-pairs of control players.
  
  
  METHODS
  It was a Cross-sectional study with one factor: previous ACL injury. We recruited 22 male (6 ACL-reconstructed and 16 uninjured control players) and 21 female (6 ACL-reconstructed and 15 uninjured control players) elite handball players who were evaluated 6.2±3.4 years after surgical ACL reconstruction. A battery of jump tests, including both bilateral and unilateral maneuvers, was performed. Two-tailed unpaired (intergroup comparison) and paired (intragroup comparison) t-tests were performed for mean comparisons. The P-value cut-off for significance was set at <0.05.
  
  
  RESULTS
  The previously ACL-reconstructed female athletes showed a lower bilateral drop jump contact time (0.429±179.9 vs. 0.349±151 s, P<0.05) and less distance reached (3.820±0.54 vs. 4.428±0.44 m, P<0.05) in the unilateral triple hop for distance (UTHD) on their reconstructed leg compared with the dominant legs of the uninjured control athletes. No significant differences were observed for any other recorded variable. Among the male athletes, no significant differences between groups were found for the studied jumping variables.
  
  
  CONCLUSIONS
  Previously ACL-reconstructed elite female handball athletes demonstrated both lower vertical bilateral drop jump (VBDJ) contact times and lower UTHD scores for the injured leg several years after injury. These deficits could contribute to an increase in ACL re-injury risk.
authors.affiliation: Research, Studies and Sport Medicine Center Government of Navarre, Navarre, Spain - mikel.izquierdo@gmail.com.
authors.forename: I
authors.initials: I
authors.lastname: Setuain
authors.forename: N
authors.initials: N
authors.lastname: Millor
authors.forename: J
authors.initials: J
authors.lastname: Alfaro
authors.forename: E
authors.initials: E
authors.lastname: Gorostiaga
authors.forename: M
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D000328:Adult; D000367:Age Factors; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D001265:Athletic Injuries / Q000503:physiopathology / Q000601:surgery*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D059385:Plyometric Exercise; D012737:Sex Factors