The Effects of Jump-Rope Training on Shoulder Isokinetic Strength in Adolescent Volleyball Players

Abstract

Objective:To investigate the effect of a 12-wk weighted-jump-rope training program on shoulder strength.Design:Pretest to posttest experimental design.Setting:University sports physiotherapy laboratory.Participants:24 healthy volleyball players age 13-16 y.Intervention:Group 1 took weighted-rope training (n = 9), group 2 took unweighted-rope training (n = 8), and group 3 did not train with any specific program (n = 7).Main Outcome Measures:Players’ strength determined with an isokinetic dynamometer (Isomed 2000) at 180 and 60°/s on external and internal rotators, supraspinatus peak torque, and total work of the dominant shoulder. Kruskal–Wallis and Mann–Whitney U tests were used to determine the difference among the groups.Results:At pretraining evaluation, there were no significant differences in the test scores of the isokinetic test of full can and empty can between the groups at 60 and 180°/s. There was no statistically significant difference for 60 and 180°/s between pretraining and posttraining assessment (P > .05) except that total eccentric work increased in groups 1 and 3 but decreased in group 2 at 180°/s during the full can (P < .05). There was no significant difference among the groups between the pretraining and posttraining testing at both 180 and 60°/s for the empty can (P > .05). Internal-rotation values at 60 and 180°/s decreased for both peak torque and total work for all groups. External-rotation peak torque and total work at 60°/s increased for group 1. External-rotation peak torque and total work at 180°/s increased for all groups.Conclusions:The results indicate that a jump-rope training program is a good conditioning method for overhead athletes because of its potential benefits to shoulder strength.