title: Gait mechanics in chronic ACL deficiency and subsequent repair.
abstract: OBJECTIVE
  To determine how normal gait patterns may change as a result of chronic anterior cruciate ligament deficiency and subsequent reconstructive surgery.
  
  
  METHODS
  Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and 3 months following reconstructive surgery, and 10 uninjured controls.
  
  
  BACKGROUND
  There is controversy whether persons with chronic anterior cruciate ligament deficiency develop a "quadriceps avoidance" pattern and how anterior cruciate ligament reconstructive surgery influences gait mechanics in these same individuals.
  
  
  METHODS
  Gait analysis was employed to determine kinematic, kinetic, and muscle Electromyographic data.
  
  
  RESULTS
  Prior to surgery, no anterior cruciate ligament deficient subject exhibited a quadriceps avoidance pattern. Following surgery, the subjects exhibited a significantly greater knee extensor moment during early stance as compared to the control group. Prior to and following surgery, anterior cruciate ligament deficient subjects demonstrated a significantly greater hip extensor moment possibly to reduce anterior tibial translation. CONCLUSIONS; These data suggest that (1) development of a quadriceps avoidance pattern is less common than previously reported, (2) anterior cruciate ligament deficient subjects accommodate through alterations of hip joint mechanics, (3) surgical repair significantly alters lower extremity gait patterns, and (4) re-establishment of pre-injury gait patterns takes longer than 3 months to occur.
  
  
  CONCLUSIONS
  The results suggest that chronic anterior cruciate ligament deficient subjects do not exhibit a quadriceps avoidance gait pattern. Surgical intervention significantly alters lower extremity gait mechanics in a population that has accommodated to anterior cruciate ligament deficiency.
authors.affiliation: Department of Physical Therapy, University of Delaware, 301 McKinly Lab, Newark, DE 19716-2591, USA. reedferb@udel.edu
authors.forename: Reed
authors.initials: R
authors.lastname: Ferber
authors.forename: Louis R
authors.initials: LR
authors.lastname: Osternig
authors.forename: Marjorie H
authors.initials: MH
authors.lastname: Woollacott
authors.forename: Noah J
authors.initials: NJ
authors.lastname: Wasielewski
authors.forename: Ji-Hang
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D015601:Injury Severity Score; D007593:Joint Instability / Q000175:diagnosis*; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000379:methods; D012016:Reference Values; D012086:Reoperation; D016474:Weight-Bearing