PENGARUH LATIHAN PLYOMETRIC (BOX JUMP) TERHADAP KEKUATAN OTOT KAKI PADA PEMAIN BOLA VOLY DI CLUB KKS BAMBALAMOTU

Lower-limb muscle strength is one of the most important physical
components in volleyball because it directly influences athletes’ ability
to perform explosive movements such as jumping, spiking, blocking,
and jump serving. However, observations at KKS Bambalamotu
Volleyball Club indicated that the players’ leg muscle strength had not
yet reached an optimal level, necessitating an effective training
intervention. Therefore, this study aimed to determine the effect of
plyometric (box jump) training on lower-limb muscle strength among
volleyball players at KKS Bambalamotu Club. This study employed an
experimental method using a one-group pretest-posttest design. The
population consisted of 12 volleyball players from KKS Bambalamotu
Club, all of whom were selected as research participants through a total
sampling technique. Lower-limb muscle strength was measured using
a vertical jump test administered before and after the intervention. The
plyometric box jump training program was conducted for six weeks with
a training frequency of three sessions per week. Data were analyzed
using a paired-samples t-test at a significance level of 0.05. The results
revealed a significant improvement in lower-limb muscle strength
following the training program. The total pretest score increased from
2,318 to 2,460 in the posttest, with a mean improvement of 11.08 points.
Hypothesis testing showed a calculated t-value of 79.14, which was
substantially higher than the critical t-table value of 1.796. These
findings indicate that the alternative hypothesis was accepted and the
null hypothesis was rejected. In conclusion, plyometric box jump
training significantly improves lower-limb muscle strength among
volleyball players and can be recommended as an effective conditioning
method to enhance volleyball performance.