Cross-exercise on quadriceps deficit after ACL reconstruction

A few studies concerning the improvement of quadriceps muscle strength deficit (QD) at an early stage following anterior cruciate ligament (ACL) reconstruction have been conducted whereas, ACL rehabilitation protocols based on contralateral quadriceps strength (QS) do not exist. Given these, the goals of our study were (1) to evaluate the effects of cross-eccentric exercise (CEE) on QD on ACL reconstructed knees, and (2) to explore any changes in QD following CEE provided at the frequencies of 3 or 5 times per week. For this study, 42 ACL-reconstructed patients were randomly assigned into 3 groups, two experimental and one control and followed an 8-week rehabilitation program. Additionally, the experimental groups received CEE for 3 and 5 days per week for 8 weeks in their uninjured knees. QS was evaluated with an isokinetic/isometric test, at 60 degrees of knee flexion of both limbs before and after completion of CEE. Two-factor ANOVA showed a significant improvement of QD between groups (F = 5.16, p = 0.01) after CEE completion on ACL reconstructed knees. Statistically significant results arose from the 3 days per week (D = 18.60, p = 0.01) and 5 days per week (D = 15.12, p = 0.04) experimental groups, whereas the control group did not yield any statistically significant differences. CEE used as an adjunct to the ACL traditional rehabilitation program at the weekly frequencies of 3 and 5 times at the early stage of reconstruction significantly improved QD.