Drop Jumping on Sand Is Characterized by Lower Power, Higher Rate of Force Development and Larger Knee Joint Range of Motion

Abstract

Plyometric training on sand is suggested to result in advanced performance in vertical jumping. However, limited information exists concerning the biomechanics of drop jumps (DJ) on sand. The purpose of the study was to compare the biomechanical parameters of DJs executed on rigid (RIGID) and sand (SAND) surface. Sixteen high level male beach-volleyball players executed DJ from 40 cm on RIGID and SAND. Force- and video-recordings were analyzed to extract the kinetic and kinematic parameters of the DJ. Results of paired-samples t-tests revealed that DJ on SAND had significantly (p < 0.05) lower jumping height, peak vertical ground reaction force, power, peak leg stiffness and peak ankle flexion angular velocity than RIGID. In addition, DJ on SAND was characterized by significantly (p < 0.05) larger rate of force development and knee joint flexion in the downward phase. No differences (p > 0.05) were observed for the temporal parameters. The compliance of SAND decreases the efficiency of the mechanisms involved in the optimization of DJ performance. Nevertheless, SAND comprises an exercise surface with less loading during the eccentric phase of the DJ, thus it can be considered as a surface that can offer injury prevention under demands for large energy expenditure.

Plyometric Exercises: Optimizing the Transfer of Training Gains to Sport Performance

“…As already mentioned, training for sports performed on compliant surface (e.g., sand for beach volley) may benefit from matching the surface stiffness (53). Although few studies have investigated the differences in biomechanical adaptations between plyometric training performed on rigid and compliant surfaces (52), they have all indicated that jump-related performances can be increased after training on both surfaces (78)(79)(80). For example, the study by Ahmadi et al (79) found that an 8-week plyometric program in women volleyball players increased drop jump height to a greater extent when the training exercises were done on a rigid surface than on sand, but the opposite was observed for the CMJ.…”

“…The ground surface (athletic track, rubber floor, sprung surface, grass, and sand) may further influence jumping performance. It recently was reported that drop jumps from 40 cm onto sand, for example, reduce jump height (~20%), vertical reaction force, and power output but increase RFD, work, knee joint range of motion, and peak ankle angular velocity during the downward phase (52). Due to the greater compliance of sand relative to a rigid surface, it can provide injury prevention under demands for large energy expenditure (53).…”

Reliability of a Pendulum Apparatus for the Execution of Plyometric Rebound Exercises and the Comparison of Their Biomechanical Parameters with Load-Matching Vertical Drop Jumps

“…The analysis of the recorded time curves provided the following parameters [7,36,39,40] using the modules of the K-Dynami (©: Iraklis A. Kollias) software:…”

Vertical Jump Kinetic Parameters on Sand and Rigid Surfaces in Young Female Volleyball Players with a Combined Background in Indoor and Beach Volleyball

“…A vast amount of information on the decreased h JUMP on sand (SJS) compared to a rigid (RJS) jumping surface exists in the literature for BV players [ 2 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. The decreased h JUMP on a SJS compared to RJS is associated with a lower force and power outputs [ 2 , 17 , 18 , 19 ] due to the less stiff surface and larger friction compared to indoor sport surfaces [ 15 ]. This deprives practitioners of applying force fast during the jumping tests, resulting in a lower power output and eventually poor jumping performance [ 17 , 18 , 19 ].…”