Relationships of the 5-Jump Test (5JT) Performance of Youth Players With Volleyball Specific' Laboratory Tests for Explosive Power.Am J Mens Health. 2020 Nov-Dec; 14(6):1557988320977686.AJ
Volleyball involves movements with and/or without horizontal approaches (i.e., spike jumps, jump setting, blocking). The 5-jump test (5JT) was suggested to assess lower limb explosive power of athletes competing in some disciplines (e.g., soccer, judo, running). It appears that no previous study has investigated the 5JT performance components in volleyball players. This study aimed to test the relationship between 5JT performance and two specific laboratory tests for explosive power (i.e., countermovement jump [CMJ] and squat jump [SJ]). Forty volleyball players (boys, mean age: 12.4 ± 0.8 years) were tested for 5JT, CMJ, and SJ tests. 5JT performance was expressed in absolute terms (m), and relative to leg length (5JTLL) and body mass (5JTBM). The SJ and CMJ tests were evaluated using the optojump photoelectric cells and the following data were collected: peak power (Pp) of jump (W, W.kg-0.67), peak jumping force (Fpeak, N), peak jumping velocity (Vpeak, m/s), peak heights of CMJ and SJ (CMJH and SJH, respectively, cm). Only significant (p < .05) Pearson product-moment correlations (r) > 0.30 were considered. 5JT performance was significantly correlated with SJ, Vpeak (r = 0.90), SJH (r = 0.88), Pp [W.kg-0.67 (r = 0.86), W (r = 0.72)], Fpeak (r = 0.45); and CMJ, Vpeak (r = 0.82), CMJH (r = 0.80), Pp [W.kg-0.67 (r = 0.89), W (r = 0.85)], Fpeak (r = 0.73). 5JTLL values were significantly related to SJ, Pp [W (r = 0.81), W.kg-0.67 (r = 0.74)], Vpeak (r = 0.82); and CMJ, Pp [W (r = 0.73), W.kg-0.67 (r = 0.84)], Vpeak (r = 0.75), Fpeak (r = 0.67)]. 5JTBM values were significantly related to SJ, Pp (W, r = -0.43). To conclude, in youth volleyball players, the 5JT may be viewed as an explosive strength diagnostic instrument under field circumstances.