Effect of running on anterior knee laxity in collegiate-level female athletes after anterior cruciate ligament reconstruction.

Agility running activities are commonly used in the latter stages of rehabilitation for anterior cruciate ligament (ACL) reconstruction. However, the effects of agility running on anterior knee laxity in these patients have not been examined. The purpose of this study was to examine changes in anterior knee laxity before and after 30 minutes of agility running exercise. Subjects (N = 9) were female athletes (mean age = 20.1 +/- 1.5 years; height = 171.7 +/- 10.4 cm; weight = 65.7 +/- 8.6 kg) with unilateral ACL reconstruction (central 1/3 patella tendon graft, postoperation range = 9-52 months, mean = 24.2 months). Measurements were made at 20 degrees and 90 degrees of knee flexion bilaterally with KT-1000 arthrometry (MEDmetric, San Diego, CA) and recorded in millimeters of displacement. Data were analyzed with an analysis of variance (ANOVA) with repeated measures (p < 0.05). Results showed no statistical differences between the ACL-reconstructed knee and the normal knee at 20 degrees and 90 degrees knee flexion. The authors conclude that the central 1/3 patella tendon graft performs comparable to the normal knee when stressed with agility running exercise; therefore, agility exercise is an appropriate, safe, short-term activity.