title: Landing mechanics between noninjured women and women with anterior cruciate ligament reconstruction during 2 jump tasks.
abstract: BACKGROUND
  Women with anterior cruciate ligament reconstruction have different neuromuscular strategies than noninjured women during functional tasks after ligament reconstruction and rehabilitation.
  
  
  OBJECTIVE
  Landing from a jump creates high loads on the knee creating dynamic instability in women with anterior cruciate ligament reconstruction, whereas noninjured women have stable knee landing mechanics.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Fifteen noninjured women and 13 women with anterior cruciate ligament reconstruction performed 5 trials of a single-legged 40-cm drop jump and 2 trials of a 20-cm up-down hop task. Multivariate analyses of variance were used to compare hip and knee joint kinematics, knee joint moments, ground-reaction forces, and electromyographic findings between the dominant leg in noninjured women and reconstructed leg in women with anterior cruciate ligament reconstruction.
  
  
  RESULTS
  No statistically significant differences between groups were found for peak hip and knee joint angles for the drop jump task. Statistically significant differences in neuromuscular activity (P = .001) and anterior-posterior knee shear forces (P < .001) were seen in women with anterior cruciate ligament reconstruction compared with noninjured women in the drop jump task. However, no statistically significant differences (P > .05) between groups were found for either peak hip and knee joint angles, peak joint kinetics, or electromyographic findings during the up-down hop task.
  
  
  CONCLUSIONS
  Women with anterior cruciate ligament reconstruction have neuromuscular strategies that allow them to land from a jump similar to healthy women, but they exhibit joint moments that could predispose them to future injury if they participate in sports that require jumping and landing.
authors.affiliation: Physical Therapy Program, School of Health Professions, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico. alexisortiz@cprs.rcm.upr.edu
authors.forename: Alexis
authors.initials: A
authors.lastname: Ortiz
authors.forename: Sharon
authors.initials: S
authors.lastname: Olson
authors.forename: Charles L
authors.initials: CL
authors.lastname: Libby
authors.forename: Elaine
authors.initials: E
authors.lastname: Trudelle-Jackson
authors.forename: Young-Hoo
authors.initials: YH
authors.lastname: Kwon
authors.forename: Bruce
authors.initials: B
authors.lastname: Etnyre
authors.forename: William
authors.initials: W
authors.lastname: Bartlett
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D054874:Athletic Performance / Q000502:physiology; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012399:Rotation