The Effectiveness of an Isokinetic Training Protocol on Muscular Imbalances in Professional Soccer Players Following an ACL Reconstruction

Abstract

It has been indicated that strength imbalances following an ACL reconstruction are essential indicators of incomplete rehabilitation programs and increased risk for re-injury. This study evaluated the effectiveness of an isokinetic training protocol on muscular imbalances in soccer players who underwent ACL surgery. Twenty-four elite male soccer players who were found to have strength imbalances six months post-surgery were recruited and randomly assigned to either the control or the experimental group. The isokinetic knee strength was assessed before and after the 5-week intervention program. Two-way analysis of variance (ANOVA) revealed a significant main effect of training intervention on torque production for the quadriceps [F(1,22)= 34.95, p<0.001, =0.61] and the hamstring [F(1,22)= 11.49, p<0.05, =0.34] of the operated leg. Furthermore, there was a significant interaction between the exercise condition and torque production for the quadriceps [F(1,22)= 23.46, p<0.001, =0.52] and the hamstring of the operated leg [F(1,22)=6.27, p<0.05, =0.22]. Planned comparisons revealed that the experimental group produced significantly greater quadriceps [t(11)= -5.42, p<0.01, d=1.22] and hamstring [t(11)=-3.09, p<0.01, d=0.45] torque post-training compared to the pre-training intervention. Additionally, there was a main effect of training intervention on the deficits of the quadriceps [F(1,22)=67.95, p<0.01, =0.76] and a significant interaction between the exercise intervention and quadriceps deficits for the two groups [F(1,22)= 32.48, p<0.001, =0.59]. Our results indicate that the isokinetic training program efficiently restored the muscular imbalances post-surgery, and therefore physical therapists and rehabilitation experts should consider incorporating this program into their therapy protocols.