The Effect of Selective Plyometric Training on the Lower Extremity Functional Performance Indexes of Female Athletes With Dynamic Knee Valgus

Considering the high prevalence of dynamic valgus and its impact on sports performance among the female athletes, the present study aimed to examine the effect of a course of selective plyometric training on the lower extremity functional performance indexes of female athletes with dynamic knee valgus. This research was a quasi-experimental study with a pretest-post-test design. The study population comprised the athletic girls with dynamic valgus referring to Bu-Ali Sina gymnasium of the University of Hamadan in 2018. Of them, 26 eligible girls who met the inclusion criteria were selected purposefully and then randomly assigned into experimental (Mean±SD age=20.25±2.34 y, Mean±SD BMI=21.27±2.75 kg/m2) and control (Mean±SD age=21.16±2.79 y, Mean±SD BMI=21.60±2.68 kg/m2) groups. The experimental group performed specific plyometric training for 8 weeks, 3 times a week. Assessing the dependent variable was done using dynamic balance, Sargent and Illinois Agility tests in the pretest and post-test. The comparisons between experimental and control groups in the pretest and post-test were made by analysis of covariance and the dependent t-tests, respectively in SPSS V. 20. The significance level was set at 0.05 or lower. Considering the pretest as the covariate parameter, a significant improvement was found for total dynamic balance (P=0.005), anterior leg (P=0.001), medial-posterior leg (P=0.001), lateral-posterior side of right leg (P=0.028), vertical jump (P=0.001) and Illinois jumping test score (P=0.001) in the experimental group. An improvement was seen in the dynamic balance and the movement performance of the participants with dynamic valgus after doing plyometric exercises that result in subsequent improvement in their exercise performance.