title: The efficacy of perturbation training in nonoperative anterior cruciate ligament rehabilitation programs for physical active individuals.
abstract: OBJECTIVE
  Treatment techniques involving perturbations of support surfaces may induce compensatory muscle activity that could improve knee stability and increase the likelihood of returning patients to high-level physical activity. The purpose of this study was to determine the efficacy of augmenting standard nonoperative anterior cruciate ligament (ACL) rehabilitation programs with a perturbation training program.
  
  
  METHODS
  Twenty-six patients with acute ACL injury or ruptures of ACL grafts participated in the study. Subjects had to have a unilateral ACL injury, be free of concomitant multiple ligament or meniscal damage requiring surgical repair, and pass a screening examination designed to identify patients who had the potential to return to high-level physical activity with nonoperative treatments. Subjects also had to be regular participants in level I activities (eg, soccer, football, basketball) or level II activities (eg, racquet sports, skiing, construction work).
  
  
  METHODS
  Subjects were randomly assigned to either a group that received a standard rehabilitation program (standard group) or a group that received the standard program augmented with a perturbation training program (perturbation group). Treatment outcome was determined from scores on the Knee Outcome Survey's Activities of Daily Living Scale (ADLS) and Sports Activity Scale, a global rating of knee function, scores on a series of single-limb hop tests, measurements of maximum isometric quadriceps femoris muscle force output, and the group frequency of unsuccessful rehabilitation. Unsuccessful rehabilitation was defined as the occurrence of an episode of giving way of the knee or failure to maintain the functional status of a rehabilitation candidate on retesting.
  
  
  RESULTS
  More subjects had unsuccessful rehabilitation in the standard group compared with the perturbation group. There was a within-group x time interaction for the ADLS, global rating of knee function, and crossover hop test scores. These scores decreased from posttraining to the 6-month follow-up for the standard group.
  
  
  CONCLUSIONS
  Although both the standard program and the perturbation training program may allow subjects to return to high-level physical activity, the perturbation training program appears to reduce the risk of continued episodes of giving way of the knee during athletic participation and allows subjects to maintain their functional status for longer periods.
authors.affiliation: Department of Physical Therapy, School of Rehabilitation and Health Sciences, University of Pittsburgh, 6035 Forbes Tower, Pittsburgh, PA 15260, USA. kfitzger+@pitt.edu.
authors.forename: G K
authors.initials: GK
authors.lastname: Fitzgerald
authors.forename: M J
authors.initials: MJ
authors.lastname: Axe
authors.forename: L
authors.initials: L
authors.lastname: Snyder-Mackler
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D016009:Chi-Square Distribution; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D008297:Male; D004856:Postural Balance; D012421:Rupture; D013177:Sports; D016896:Treatment Outcome