In this cross-sectional study, the qualitative and quantitative throwing performance of male and female athletes (6 to 16 years of age) was analyzed. The goal of this study was to assess whether ...there were gender based qualitative and quantitative differences in throwing performance of young athletes, throughout three different age bands (childhood, pubescence, and adolescence). Furthermore, we explored whether all components of the throwing movement are equally affected by gender differences. Focus was placed on five essential components of action: trunk, forearm, humerus, stepping, and backswing. Therefore, children and adolescents (
= 96) were invited to throw three times from three different distances, while aiming at a target placed at shoulder height. The participants were aspiring athletes, competitive in the sport handball. For analyzing the quality of movement the component approach of Halverson and Roberton (1984) was used. The throwing accuracy was noted and used to evaluate the quantitative performance of the throwing movement. Throughout three different age bands, no statistically significant difference was found between genders in throwing accuracy, i.e., quantitative performance. Regarding the qualitative evaluation of the throwing movement, male and female athletes differed significantly. The component approach yielded higher scores for male than for female participants. As expected, with increasing age qualitative and quantitative performance of male and female athletes improved. These results suggest that there are gender-specific differences in qualitative throwing performance, but not necessarily in quantitative throwing performance. Exploration shows that differences in the qualitative throwing performance were seen in specific components of action. Male and female athletes demonstrated similar movement patterns in humerus and forearm actions, but differed in trunk, stepping, and backswing actions.
Handball is a team sport in which changing direction, running fast-slowly, jumping, throwing, throwing accuracy, and tackles are at the forefront. For basic throws in the game, throwing speed and ...accuracy are important factors for a successful throw. In this context, the aim of this study is to evaluate the effects of body composition, isokinetic strength, handgrip strength, and static and dynamic balance parameters on throwing speed and accuracy in handball players. A total of 20 male handball players with an average age of 14.95±0.24 years and an average sports age of 4.15±0.44 years participated in the study voluntarily. Body composition, static and dynamic balance, hand grip strength, shoulder and arm rotation, throwing velocity and accuracy tests were performed on the athletes. While a negative correlation was found between body weight (r=-0.61), body mass index (r=-0.66), body muscle mass (r=-0.5), body fat mass (r=-0.58), Body fat % (r=0.61), Dominant arm muscle (r=-0.52) parameters and throwing accuracy, a positive correlation was found between dominant hand grip (r=0.59) and dominant arm shoulder internal rotation strength (r=0.59), non-dominant arm shoulder internal rotation strength parameters and throwing velocity (p<0.05). No correlation was found in the static and dynamic balance parameter. In line with the findings of the study, the static and dynamic balance parameters of the handball players did not have an effect on the throwing velocity and accuracy. However, while anthropometric characteristics such as body weight, body fat percentage and mass, and muscle mass had an effect on throwing accuracy, it can be said that hand grip strength, isokinetic shoulder internal and external rotation strength were effective on throwing velocity.
Mechanical power limitations emerge from the physical trade-off between force and velocity. Many biological systems incorporate power-enhancing mechanisms enabling extraordinary accelerations at ...small sizes. We establish how power enhancement emerges through the dynamic coupling of motors, springs, and latches and reveal how each displays its own force-velocity behavior. We mathematically demonstrate a tunable performance space for spring-actuated movement that is applicable to biological and synthetic systems. Incorporating nonideal spring behavior and parameterizing latch dynamics allows the identification of critical transitions in mass and trade-offs in spring scaling, both of which offer explanations for long-observed scaling patterns in biological systems. This analysis defines the cascading challenges of power enhancement, explores their emergent effects in biological and engineered systems, and charts a pathway for higher-level analysis and synthesis of power-amplified systems.
The aim of this study was to retrospectively compare the fastball profiles of pitchers who had previously sustained grade I or II ulnar collateral ligament (UCL) injuries, were rehabilitated, and ...released back for competition with those of pitchers with no history of elbow injury.
Eighteen pitchers from the pitching staff of 1 National Collegiate Athletic Association Division III team participated in this study. Group 1 had a history of grade I or II UCL injury (n = 8), and group 2 (n = 10) did not. A computerized pitch tracking device was used to analyze ball movement and pitching mechanics. The hypothesis was that the pitchers with a history of injury (group 1) would display differing fastball velocity-ball movement relationships compared to those without (group 2).
The groups had similar heights, weights, pitching experiences, and arm slot positions at ball release. The pitching coach-determined preinjury arm slot position and the postinjury computerized pitch tracking device measurements after return to competition displayed strong agreement (r = 0.83), suggesting comparable pre and postinjury pitching techniques. The groups had comparable glenohumeral joint range of motion and fastball profiles, except that group 1 released the ball at a 2.5 times lesser horizontal distance away from the pitching rubber center. Group 2 also displayed consistently more robust and more frequent fastball movement relationships with velocity, horizontal break, and vertical break than group 1.
Reduced horizontal ball release distances at comparable vertical ball release heights without changes in the arm slot position suggest that pitchers with a history of grade I or II UCL injury have greater contralateral trunk tilt and elbow flexion at ball release. Increased contralateral trunk tilt may occur to increase pitch velocity at the expense of ball movement while placing the pitching elbow in a potentially injurious position. Computerized fastball profile analysis using a computerized pitch tracking device, in conjunction with coach pitching technique observation, and team medical staff clinical examination may help better identify pitchers with an increased risk of UCL injury.
Diagnostic II.
A two-experiment study assessed throwing performance in VR and real life. The first experiment was a direct comparison of a carnival type throwing game in which participants attempted to throw 20 ...balls into a bucket from distances of 5 and 10 ft. Fifteen participants completed the task in both real life and in an identical VR environment. In the second experiment, the same task was repeated at the 5ft distance only with the addition of a randomized order of three different VR controllers and the real-life condition. Results from both experiments indicate substantial differences between real life and VR performance along with differences between controllers. Significant VR research has stressed enhancing visual quality to better replicate real life. However, the focus needs to shift to examine creating accurate psychomotor interactions to achieve more accurate performance and ultimately training success.
•The convection in the micro THs center declines with the increasing ARs from 6.25:1 to 1.67:1.•The convection-dependent additives formed diverse adsorption states with different convection.•The ...defect-free filling process gradually converted into the insufficient filling process with decreasing ARs.•The micro THs with AR above 3.33:1 can be fully filled with a uniform bright Cu surface preferentially orientated to (111).
In this work, we combined the computational simulation and experiments to explore the convection on filling characteristics of the micro through-holes (THs) with multiple aspect ratio (ARs). The micro THs with ARs 6.25:1∼1.67:1 (thickness 500 μm) were chosen as research targets. The computational model was established based on the actual state of Haring-Cell, and attention was fixed on the convection distribution in the micro THs. The interaction mechanism of additives with the changing ARs systematically explored by electrochemical measurements. The simulation results show that the convection in the micro THs center declines with the increasing AR. The convection-dependent additives formed diverse adsorption states around the micro THs with different ARs, providing two kinds of Cu filling processes, including defect-free filling and insufficient filling. The weak convection is conducive to the adsorption of the accelerator and detrimental to the adsorption of the suppressor, which accelerates the Cu electrodeposition and elevates the throwing power (TP) value to over 100% to form the defect-free filling. Strong convection is instrumental in the adsorption of the leveler so that a uniform Cu film thickness can be obtained but to create the insufficient filling. Simulation and electroplating experiments show that the AR of 3.33:1 is the cut-off point of the flow field distribution and the electroplating processes. The micro THs with AR higher than 3.33:1 can be fully filled with a uniform bright Cu surface.
The article presents a study of the raw cotton movement on the surface of a throwing drum with inclined spikes of a saw gin. The considered system consists of two separate sections. The interaction ...of cotton with actuating tools in the first section takes place on the surface of the spike of the throwing drum, and in the second section, it occurs with separation from the spikes of the throwing drum until it hits the blade of the saw cylinder. It was determined that with an increase in ω, the path and time for the passage of raw cotton along the surface of the spike of the throwing drum decreased while the angle and height of the cotton hit on the surface of the saw cylinder increased. As a result of studying the kinematics and size of the saw gin throwing drum using the raw cotton movement, the relative velocity of cotton in the falling zone was 0.2667 m/s at an angle of 114º relative to the drum.
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