The efficacy of perturbation training in nonoperative anterior cruciate ligament rehabilitation programs for physically active individuals

Background and Purpose. Treatment techniques involving perturbations of sup port surfaces may induce compensatory muscle activity that could improve kn ee stability and increase the likelihood of returning patients to high-leve l physical activity. The purpose of this study was to determine the efficac y of augmenting standard nonoperative anterior cruciate ligament (ACL) reha bilitation programs with a perturbation training program. Subjects. Twenty- six patients with an acute ACL injury or ruptures of ACL grafts participate d in the study. Subjects had to have a unilateral ACL injury, be free of co ncomitant multiple ligament or meniscal damage requiring surgical repair, a nd pass a screening examination designed to identify patients who had the p otential to return to high-level physical activity with nonoperative treatm ents. Subjects also had to be regular participants in level I activities (e g, soccer, football, basketball) or level II activities (eg, racquet sports , skiing, construction work). Methods. Subjects were randomly assigned to e ither a group that received a standard rehabilitation program (standard gro up) or a group that received the standard program augmented with a perturba tion training program (perturbation group). Treatment outcome was determine d 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 qu adriceps femoris muscle force output, and the group frequency of unsuccessf ul rehabilitation. Unsuccessful rehabilitation was defined as the occurrenc e of an episode of giving way of the knee or failure to maintain the functi onal status of a rehabilitation candidate on retesting. Results. More subje cts had unsuccessful rehabilitation in the standard group compared with the perturbation group. There was a within-group X time interaction for the AD LS, global rating of knee function, and crossover hop test scores. These sc ores decreased from posttraining to the 6-month follow-up for the standard group. Conclusion and Discussion. Although both the standard program and th e 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 partic ipation, and it allows subjects to maintain their functional status for lon ger periods.