Statistical analysis
Descriptive statistics were used to summarize the characteristics of the participants and measurements. The normality of data was assessed with the Shapiro–Wilk test. ANCOVA (Pre-test as a covariate) followed by Bonferroni post hoc test was used to evaluate the effects of a 4-week plyometric training on activity pattern variables of 4 muscles in different phases of a drop jump. Bonferroni's post hoc test was performed to evaluate the differences within a group. All statistical analysis was performed using Spss V22. A p < 0.05 was considered for statistical significance.