VERTICAL JUMPING PERFORMANCE RELATES TO SPRINTING PERFORMANCE OVER SHORT DISTANCES AND DIFFERENT SECTIONS

A high level of sprinting performance is relevant in various sports. Because of the transition of movement patterns in different sprint sections there is a shift in the relevance of speed-strength of the knee and hip extensors, and stretch-shortening cycle performance seems conceivable. Fifty-six physical education students (23.70 ± 3.00 years, 176.9 ± 8.10cm, 74.20 ± 10.30kg) were investigated. They performed sprints up to 30m in which different sections were analyzed and vertical jumps (squat jump, countermovement jump, drop jump from different dropping heights). Vertical jumping tests in squat jump and countermovement jump revealed mean values of 31.95 ± 6.56cm and 34.28 ± 7.47cm, respectively, while the drop jumps showed mean RSI values between 155.11 ± 36.77 and 168.24 ± 36.29 dependent on the dropping height. The sprint test showed a mean performance of 4.464 ± .343s (30m). The correlational analysis showed significant correlations (p < .01) for vertical jumping height with all sprinting sections (r = −.652 to −.834). Drop jump performance also showed significant correlations (p < .01) with all the sections (r = −.379 to −.594). The results let us hypothesize that the observed sample generated similar ground-reaction forces in the sprint and drop jump from a height of 40 cm.

Biomechanical Characteristics of Vertical Jumping of Preschool Children in China Based on Motion Capture and Simulation Modeling

Vertical jumping is one of the basic motor skills, and it is an essential part of many sports. The main purpose of this paper is to investigate characteristics of vertical jumping of children. This paper uses a motion capture system, three-dimensional platforms, and a simulation modeling system to analyze the kinematics and dynamics performance of children’s vertical jumping. The compression time increases from 3 to 4 years old, and flight height and time increases with age and stage gradually. In the compression phase and pushing phase, the hip and knee joint play a major role; in the landing phase, the knee and ankle joint play a major role. Muscle forces are mainly affected by age, and the three types of muscle force had two different trends. The muscle force of the shank and thigh increased with age, and the pelvic girdle muscles showed an “low–high–low” trend. The regression model suggests that the force of GMiP and the hip angular velocity have a great influence on jumping ability. Therefore, if we want to improve the jumping ability of preschool children, we should pay more attention to hip exercises. We should integrate the hip exercises into interesting games, which are more in line with their physical and mental health.

Vertical Jumping as a Monitoring Tool in Endurance Runners: A Brief Review

Jumping performance (e.g., countermovement jump [CMJ]), as a measure of neuromuscular performance, has been suggested as an easy-to-use tool which simultaneously provides neuromuscular and metabolic information and, thereby, allows coaches to confidently monitor the status of their athletes during a workout. This hypothesis has been satisfactorily tested with sprint athletes. However, the rationale for the use of CMJ height loss as an index to monitor the workload during an endurance running session is not sufficiently evidence-based. First, it is assumed that a CMJ height loss occurs during typical interval training for endurance runners. Second, it is also assumed that a significant relationship between metabolic stress and the neuromuscular strain induced during these endurance workouts exists. These two assumptions will be questioned in this review by critically analyzing the kinetics of CMJ performance during and after running workouts, and the relationship between neuromuscular and physiological stress induced during different protocols in endurance runners. The current evidence shows that fatigue induced by common running workouts for endurance runners does not counterbalance the potentiation effect in the CMJ height. Additionally, the findings reported among different studies are consistent regarding the lack of association between CMJ height loss and physiological stress during interval sessions in endurance runners. In practical terms, the authors suggest that this marker of neuromuscular fatigue may not be used to regulate the external training load during running workouts in endurance runners. Nevertheless, the analysis of CMJ height during running workouts may serve to monitor chronic adaptations to training in endurance runners.

Vertical Jump in National Volleyball-Basketball Team’s Women's in Albania

Volleyball and Basketball women’s have different performances from each other due to their special specifics of the game. From the specificity of their training, there are differences in the physical qualities of individual and team sports performance, where one of the elements is vertical jumping. This study is concentrated on two teams: Women’s Volleyball Team (V) and Women’s Basketball Team (B) 15 members each, focusing on 30 subjects. Players were measured in physical parameters; Age (V-24: B-27), Body Height (V-180.4cm; B-173.4cm), Body Weight (V-70.37kg; B-63.88kg), BMI (V-21.67 percent; B-20.93 percent). The players performed the test DJ60cm in the platform Leonardo® Ground Force Reaction Plate (GRFP) which expresses Force max (kN), Power max (w/kg), Time Contact (TCs), Air Time (TAs), TA/TCs. The results obtained by GRFP showed different team values of the two sports in the parameters of Fmax V65.19-B74.07n/kg, Pmax V31.26-B23.06w/kg, TCs V0.231-B0.198, TAs V0.436-B0.34 and TA/TCѕec V1.96ѕ-B1.71ѕec. Results revealed that V players jumped higher (p, 0.001) than B players. Finally, the Drop Jump60cm test has different performance between individual players, despite the fact that in the team average it turned out that Volleyball players is higher in this test. Drop Jump is the typical plyometric test. Furthermore, tests such as DJ can be a useful method for assessing differences and monitoring vertical jump training programs from collective sports.

Unilateral and Bilateral Post-Activation Performance Enhancement on Jump Performance and Agility

This study aimed to compare the effects of the post-activation performance enhancement (PAPE) of two different types of warm-ups, unilateral and bilateral, on the performance in vertical jumping and agility of healthy subjects with strength training experience. In the study, 17 subjects (12 men and 5 women) performed two different PAPE protocols: unilateral squat (UT) and bilateral squat (BT). The height of the subjects’ countermovement jump (CMJ) and the subjects’ time to perform the T-agility test (TAT) were measured before and after executing the PAPE warm-up. The squats were performed at a velocity of 0.59 m·s−1 with three sets of three repetitions, with a 3-min rest between sets and a 5-min rest after both uni-and bilateral PAPE warm-ups before taking the tests again. For statistical analysis, we applied ANOVA and calculated the effect size. The results showed that the PAPE for each case decreased the CMJ height but generated significant improvements in the total time taken for the T-agility test (p < 0.01); however, in both cases, the effect sizes were trivial. In conclusion, it is possible to observe that the PAPE, performed both unilaterally and bilaterally, negatively affects the performance in the vertical jump, showing moderate effect sizes. However, both PAPE protocols show performance benefits in agility tests, with a large effect size for the unilateral protocol and moderate for the bilateral protocol.

Optimization-based subject-specific planar human vertical jumping prediction: Effect of elbow flexion and weighted vest

Jumping strategies differ considerably depending on athletes’ physical activity demands. In general, the jumping motion is desired to have excellent performance and low injury risk. Both of these outcomes can be achieved by modifying athletes’ jumping and landing mechanics. This paper presents a consecutive study on the optimization-based subject-specific planar human vertical jumping to test different loading conditions (weighted vest) during jumping with or without elbow flexion during the arm-swing based on the validated prediction model in the first part of this study. The sagittal plane skeletal model simulates the weighting, unweighting, breaking, propulsion phases and considers four loading conditions: 0%, 5%, 10%, and 15% body weight. Results show that the maximum ground reaction forces, the body center of mass position, and velocities at the take-off instant are different for different loading conditions and with/without elbow flexion. The optimization formulation is solved using MATLAB® with 35 design variables with 197 nonlinear constraints for a five-segment body model and 42 design variables with 227 nonlinear constraints for a six-segment body model. Both models are computationally efficient, and they can predict ground reaction forces, the body center of mass position, and velocity. This work is novel in the sense that presents a simulation model capable of considering different external loading conditions and the effect of elbow flexion during arm swing.

Relationship between Asymmetries Measured on Different Levels in Elite Basketball Players

In this study, we investigated the association of magnitude and agreement in direction between asymmetries measured on single-joint (hip and trunk), complex movement (jumping), and skill (change of direction (CoD)) levels. The study sample comprised 43 junior- and senior-level (age = 20.5 ± 6.0 years; height = 194.5 ± 7.2 cm; body mass = 86.8 ± 10.1 kg) elite male basketball players. Both limbs/sides were tested in hip and trunk isometric strength; passive range of motion (RoM); unilateral, horizontal, and vertical jumping; and CoD tests, from which asymmetry indexes were calculated. The associations between asymmetry magnitudes were calculated with Spearman’s ρ correlation coefficient. The agreement between the direction of asymmetries on different levels was calculated with Cohen’’s Kappa (κ) coefficient. The average magnitude of asymmetry varied substantially (2.9–40.3%). Most associations between asymmetry magnitudes measured on different levels were small and statistically non-significant, with a few exceptions of moderate and large associations. Asymmetry in single-leg countermovement jump parameters was strongly associated with hip abduction maximal strength (ρ = 0.58 and 0.50, p < 0.01). Agreement between asymmetry directions was slight to fair, with a few moderate exceptions. Results indicate that multiple tests are needed to obtain a comprehensive picture of athletes’ asymmetries and that universal thresholds and golden standard tests for return to play should be reconsidered and reinvestigated.

ECCENTRIC PEAK TORQUE OF THE KNEE FLEXORS AND EXTENSORS RELATES TO BACKWARD SOMERSAULT HEIGHT IN FEMALE JUNIOR ARTISTIC GYMNASTS

Artistic gymnastics consist of a high amount of jumping actions with rotations around one or more axes. To achieve an optimal flight height to perform the desired number of rotations, the movement pattern and the floor characteristics have to be concerted optimally. To account for the required leg stiffness to utilize the floor’s elasticity, the leg musculature has to generate high forces during the ground contact in an eccentric manner. Thus, eccentric strength of the knee musculature might play an important role for somersault height and run-up velocity in the vault. We investigated the correlation of eccentric peak torque of the knee flexors and extensors and vertical jumping height with backward somersault height and sprinting velocity in female junior artistic gymnasts. The results showed medium to strong, significant correlations between eccentric peak torque and backward somersault height as well as sprinting velocity. Vertical jumping height revealed significant correlations with somersault height and sprinting velocity. Eccentric strength seems to play an important role in joint stiffness regulation to utilize the elastic recoil of gymnastic floors and springboards. In the sprint approaching the vault, the same mechanism seems apparent and is in accordance with findings regarding the sprint in different sports.

A Biologically Inspired Height-Adjustable Jumping Robot

This paper presents the design and development of a miniature integrated jumping and running robot that can adjust its route trajectory and has passive self-righting. The jumping mechanism of the robot was developed by using a novel design strategy that combines hard-bodied animal (springtail) and soft-bodied animal (gall midge larvae) locomotion. It could reach a height of about 1.5 m under a load of 98.6 g and a height of about 1.2 m under a load of 156.8 g. To enhance the jumping flexibility of the robot, a clutch system with an adjustable height and launch time control was used such that the robot could freely switch to appropriate jumping heights. In addition, the robot has a shell with passive righting to protect the robot while landing and automatically self-righting it after landing, which makes the continuous jumping, running, and steering of the robot possible. The two-wheel mechanism integrated at the bottom of the housing mechanism provides the robot with horizontal running locomotion, which is combined with the vertical jumping locomotion to obtain different locomotion trajectories. This robot has the functions of obstacle surmounting, track adjustability, and load- and self-righting, which has strong practical application value.