The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p < .05) surface effects on the jump height, the ankle joint angle at the lowest height of the body center of mass and the ankle angular velocity. Also, significant arm swing effects were found on jump height, maximum power output, temporal parameters, range of motion and angular velocity of the hip. These findings could be attributed to the instability of the sand, which resulted in reduced peak power output due to the differences of body configuration at the lowest body position and lower limb joints' range of motion. The combined effect of the backward arm swing and the recoil of the sand that resulted in decreased resistance at ankle plantar flexion should be controlled at the preparation of selected jumping tasks in beach-volleyball.

Ankle flexibility and isokinetic knee torque/power generating capacity were previously suggested to contribute or to be correlated to the vertical countermovement jump (CMJ) performance. The aim of this study was to investigate the effect of the passive ankle joint dorsi flexion (θ_PDF) and the knee muscle’s isokinetic torque and power on the CMJ in adolescent female volleyball players. The θ_PDF at a knee extension angle of 140 degrees were measured for 37 female post-pubertal volleyball players. Then, the players were assigned to either the flexible (n = 10) or inflexible (n = 14) groups according to earlier recommended criteria. Testing included the CMJ with and without an arm swing, and maximal knee extensions and flexions in 3 angular velocities on an isokinetic dynamometer. CMJ height performed with or without an arm swing (r₍₂₂₎ = 0.563, p = 0.040 and r₍₂₂₎ = 0.518, p = 0.009, respectively) and relative power (r₍₂₂₎ = 0.517, p = 0.010 and r₍₂₂₎ = 0.446, p = 0.030, respectively) were positively correlated with the extensors’ torque at 180°/s and were negatively correlated with the flexibility level of the dominant side ankle (r₍₂₂₎ = −0.529, p = 0.008 and r₍₂₂₎ = −0.576, p = 0.030, respectively). A moderate positive correlation was also revealed between the CMJ height with and without an arm swing and the power of the non-dominant knee extensors (r₍₂₂₎ = 0.458, p = 0.024 and r₍₂₂₎ = 0.402, p = 0.049, respectively) and flexors (r₍₂₂₎ = 0.484, p = 0.016 and r₍₂₂₎ = 0.477, p = 0.018, respectively). Results of the 2 × 2 repeated ANOVA measurements revealed that flexible players jumped significantly (p < 0.05) higher during the CMJs, whilst there was a group effect only on the isokinetic knee extensor muscles’ torque. In conclusion, a more flexible ankle joint and a higher isokinetic knee extensor’s torque generating capacity resulted in higher CMJ performance. Therefore, ankle flexibility should be emphasized in training and is suggested to be included in preseason screening tests of youth female volleyball players.

A flexible ankle joint is suggested to be a contributing factor for vertical squat jump (SQJ) performance. The purpose of the study was to investigate the effect of the active (ACT) and passive (PAS) ankle joint range of motion (ROM) on SQJ performed by adolescent female volleyball players. ACT and PAS ankle ROM at knee extension angles of 90, 140, and 180 degrees (180 degrees: full extension) were measured with a video analysis method for 35 female post-pubertal volleyball players (16.3 ± 1.1 yrs, 1.80 ± 0.04 m, 68.8 ± 6.8 kg). Additionally, the players fulfilling previously recommended criteria were assigned to the flexible (n = 10) and inflexible (n = 8) groups and executed SQJ with and without an arm swing on a force-plate. Results of the 2 × 2 × 3 MANOVA revealed a significant (p < 0.05) flexibility type and knee angle effect, as ankle ROM was larger in PAS compared to ACT and as the knee joint progressed from 90 to 180 degrees extension. The 2 × 2 ANOVA revealed a significant (p < 0.05) group effect, as flexible players jumped higher in the arm swing SQJ, along with a significant arm swing effect on key SQJ kinetic parameters. In conclusion, a more flexible ankle joint result in improved SQJ performance. Therefore, ankle flexibility training should be implemented in youth volleyball players.

The purpose of the study is to examine the effect of the ankle joint range of motion (ROM) on the vertical jump (VJ) performance of adult handball players. The active (ACT) and passive (PAS) ankle joint ROM of 12 male members of the U21 National Handball Team with the knee joint at 0°, 40°, and 90° flexion (0° = fully extended knee) was evaluated using a video analysis measuring method. Participants also performed maximum VJ with (CMJ) and without (SQJ) countermovement, as well as with (AS) and without (NAS) an arm swing. Statistical analyses included 2 × 2 × 3 MANOVA, 2 × 2 repeated measures ANOVA, and Pearson’s correlation. Results reveal that PAS-ROM was larger (p < 0.05) in all knee joint flexion angles. ROM was smaller (p < 0.05) by approximately 10° at 0° compared to 90° knee flexion. No lateral effects on ROM due to the handedness of the players were observed. AS and CM resulted in increased jump height (p < 0.05). Finally, ACT-ROM when the knee joint was flexed at 40° was highly correlated (r ≥ 0.66, p < 0.05) with VJ performance except for CMJ-AS. In conclusion, the differences in the bi-articular gastrocnemius muscle flexibility due to the alteration of the angular position of the examined joints affected the ability to generate impulse during the VJ tests.

PurposeLong-term training specificity is thought to alter performance in tests evaluating strength and power production capability. The aim of the present study was to provide additional information to the limited existing knowledge concerning the possible differences of the force/time profile of squat jumping among different groups of young female athletes.MethodsOne hundred and seventy-three adult women (20.1 ± 2.8 years, 1.71 ± 0.09 m, 65.6 ± 10.3 kg, mean ± SD for age, height, and mass, respectively) engaged in track and field (TF), volleyball (VO), handball (HA), basketball (BA), and physical education students (PE) executed maximal squat jumps (SQJ) on a force plate. Pearson's correlation was used to identify the relationship between SQJ performance, the anthropometric characteristics and the biomechanical parameters. Differences concerning the biomechanical parameters among groups were investigated with analysis of variance, while the force- (FPD) or time- (TPD) dependency of SQJ execution was examined using principal components analysis (PCA).ResultsSQJ was unrelated to body height but significantly correlated with body mass (r = −0.26, p = 0.001). TF jumped higher and produced larger peak body power output compared to all the other groups (p < 0.05). All athletes were superior to PE since they performed the SQJ with a longer (p < 0.05) vertical body center of mass trajectory during the propulsion phase. PCA results revealed that TF significantly differentiated than the other groups by relying on FPD.ConclusionVarious different profiles of FPD and TPD were detected due to different sporting background in young female athletes. Since TF superiority in SQJ was relied on the larger power production and a greater FPD, female indoor team sport athletes are suggested to execute jumping exercises adopting the jumping strategies utilized by TF