PENGARUH LATIHAN SQUAD JUMP TERHADAP PENINGKATAN POWER OTOT TUNGKAI SISWA KELAS VII PADA PERMAINAN BOLA VOLI SMP NEGERI 1 BARAS

This study aims to analyze the effect of squat jump training on improving the
leg muscle power of seventh-grade students in the volleyball program at SMP
Negeri 1 Baras. The method used in this study was an experimental design
with a one-group pretest–posttest design. The population of this study
consisted of all seventh-grade students at SMP Negeri 1 Baras, while the
sample consisted of 15 students selected through purposive sampling. The
instrument used to measure leg muscle power was the vertical jump test. The
research procedure began with an initial test (pretest), followed by the
implementation of squat jump training over several sessions, and concluded
with a final test (posttest). The data obtained were analyzed using the
Shapiro–Wilk normality test and the paired-sample t-test. The results of the
analysis indicated that the research data were normally distributed. The
paired-sample t-test revealed a significant difference between the pretest (M
= 33.07) and the posttest (M = 36.87), with t(14) = 9.668, P < 0.05, indicating
an 11.49% improvement in leg muscle power. The average posttest score was
higher than the pretest score, indicating an increase in students’ leg muscle
power following participation in squat jump training. Based on the statistical
analysis, it can be concluded that squat jump training has a significant effect
on improving the leg muscle power of seventh-grade students in the
volleyball program at SMP Negeri 1 Baras.