Little is known about the differences in vertical jump biomechanics executed on rigid (RJS) and sand (SJS) surfaces in female indoor and beach volleyball players. Eleven young female beach volleyball players with a combined indoor and beach volleyball sport background performed squat jumps, countermovement jumps with and without an arm swing, and drop jumps from 40 cm on a RJS (force plate) and SJS (sand pit attached to the force plate). The results of the 2 (surface) × 4 (vertical jump test) repeated-measure ANOVA revealed a significant (p < 0.05) main effect of the surface and the vertical jump test on the jump height and time to achieve peak vertical body center of mass velocity. A significant (p < 0.05) main effect of the test, but not of the surface (p > 0.05), was observed for the other examined biomechanical parameters. The only significant (p < 0.05) jump height gain difference between RJS and SJS was observed for the utilization of the stretch-shortening cycle, which was higher in SJS (15.4%) compared to RJS (7.5%). In conclusion, as the testing was conducted during the beach volleyball competitive season, the examined female players showed adaptations relating the effective utilization of the pre-stretch and enhanced stability during the execution of the vertical jump tests on a SJS compared to RJS.
Keywords: biomechanical analysis; drop jump; gender differences; kinematics; kinetics; stretch-shortening cycle; surface stability; vertical jumping.