The Effects of Unstable Strength Training on Lower Limb Stability in Adolescent Volleyball Players in China.

BACKGROUND

This study aimed to compare the effects of unstable strength training (UST) and traditional strength training (TST) on lower-body stability in adolescent volleyball players in China.

METHODS

This stratified randomized controlled trial recruited 62 eligible athletes from Shandong Province. Participants were assigned to either the UST group or the TST group, and both groups completed a 10-week training program.

RESULTS

Multivariate analysis of variance (MANOVA) for within-group effects revealed statistically significant improvements in all dependent variables for both the UST and TST groups (p < 0.05), FMS [F = 35.112, p < 0.001, η2 = 0.377]; and balance ability differences, left-side score (LS) [F = 8.268, p < 0.001, η2 = 0.125], right-side score (RS) [F = 8.094, p < 0.001, η2 = 0.122]. Furthermore, after controlling for covariates, MANCOVA analysis for between-group effects still showed statistically significant differences between the UST and TST groups on all post-test dependent variables. These differences included: functional differences, FMS [F = 34.412, p < 0.001, η2 = 0.389]; LS [F = 8.079, p < 0.01, η2 = 0.130]; and RS [F = 8.532, p < 0.001, η2 = 0.136].

CONCLUSION

UST is more effective than TST in improving athletes' lower-body stability performance. Future studies should explore the application of UST in other sports and examine its effects on parameters beyond functional movement and balance.