title: Evaluation of lower limb kinetics during gait, sprint and hop tests before and after anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  The purpose of this study was to evaluate the functional status prior to and at different times after anterior cruciate ligament reconstruction (ACLR), and to analyze the changes in the kinetic patterns of the involved and uninvolved lower limb during gait, sprint and three hop tests.
  
  
  METHODS
  Seventy-four male patients with an ACL injury were included in the study. All patients performed a standardized kinetic protocol including gait, sprint and three hop tests (single-leg hop, drop vertical jump and vertical jump tests), preoperatively and at 3, 6, and 12 months after ACLR with a semitendinosus gracilis tendon autograft. Measurements were performed with two force plates. The lower limb symmetry index (LSI) was calculated to determine whether a side-to-side leg difference was classified as normal (LSI >90%) or abnormal (LSI <90%).
  
  
  RESULTS
  The LSI presented high values (>90%) at almost all times before and after ACLR in gait, sprint and single-leg hop tests (p < 0.005), with a tendency to increase postoperatively. A lower LSI was observed (<90%) in tests where both extremities were tested simultaneously, such as the drop vertical jump and vertical hop tests (p < 0.05).
  
  
  CONCLUSIONS
  We observed a tendency to increase symmetry restoration in the kinetics of the involved and uninvolved limb up to twelve months after ACLR, especially in those tests, in which, both limbs were tested individually (gait analysis, sprint and single-leg hop tests). Therefore, the isolation of the involved and uninvolved limb seems to be a critical component in the functional rehabilitation and evaluation of patients before and after ACLR.
  
  
  METHODS
  level III.
authors.affiliation: Hospital Special Surgery, 535 E 70th St, New York City, NY, 10021, USA. jmoyaangeler@gmail.com.|, 144 E 74th St 3r, New York, NY, 10021, USA. jmoyaangeler@gmail.com.
authors.forename: Joaquín
authors.identifier: http://orcid.org/0000-0002-3520-2521
authors.initials: J
authors.lastname: Moya-Angeler
authors.affiliation: University Hospital Gregorio Marañon, Calle del Dr. Esquerdo, 46, 28007, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Vaquero
authors.affiliation: School of Medicine, University San Pablo-CEU, Madrid, Urbanización Montepríncipe, Boadilla del Monte, 28668, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Forriol
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D064592:Autografts; D005080:Exercise Test / Q000379:methods; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology*; D000071976:Gracilis Muscle / Q000637:transplantation; D006801:Humans; D007700:Kinetics; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D011184:Postoperative Period; D057234:Preoperative Period; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D012189:Retrospective Studies; D012420:Running / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: ACL deficiency; ACL reconstruction; Hop tests; Knee kinetics; Semitendinosus gracilis autograft