INVESTIGATION OF A THEORETICAL MODEL FOR THE ROTATIONAL SHOT PUT TECHNIQUE

This study aimed to investigate the causal relationships among biomechanical variables for achieving high release velocity in male shot putter and create a theoretical model for the rotational shot put technique. The throwing motions of 22 male shot putters were videotaped and analysed using the 3D DLT method. Path analysis was used to examine causal relationships among biomechanical variables. The examined model consisted of three kinetic and eight kinematic variables that significantly related to a higher release velocity directly or indirectly. Two key factors were identified in shot put performance with the rotational technique: (1) increasing of impulse of the shot at delivery phase, and (2) creating greater linear and angular momentum before delivery. Future research should confirm or extend this potential causal mechanism of contributors to shot release velocity

WHY OVER-ROTATION IS NOT GOOD FOR ROTATIONAL SHOT PUT?

This study used three-dimensional motion analysis to determine the motion of rotational shot put. We sought to elucidate the effect of over-rotation in rotational shot put. The results showed that dirction of the center of gravity of the body (CG direction) correlates with the angular momentum of the shot-and-thrower system. As the magnitude of variability of CG direction relative to the horizontal plane increased, angular momentum of the shot-and-thrower system relative to its vertical axis decreased at the second turn @ < 0.05). CG direction showed a strong dependence on the contact position of the foot. We suggest that throwers avoid over-rotation by placing the foot straight from L-off to Lon

CLASSIFICATION OF THE ROTATIONAL SHOT-PUT BASED ON DURATION TIME OF MOTION PHASES

This study aimed to investigate the relationships between throwing distance and duration times of motion phases in the rotational shot-put and attempted to classify the throw based on duration times. A total of 181 recorded trials performed by male shot-putters were obtained, and their duration time and the ratio of duration time of defined motion phases were analysed. Duration time and the ratio of duration time were not correlated with throwing distance for all motion phases. Result of a cluster analysis indicated that athletes could be classified in two groups and there were significant differences in duration time at initiation and later phases between the groups. As a result, it is suggested that the changes in duration time might not influence the throwing distance. In addition, it was identified that there are two kinds of group based on the duration times in the rotational shot-put

KINEMATIC AND TECHNICAL FACTORS FOR ACCELERATION OF WHOLE BODY IN ROTATIONAL SHOT PUT TECHNIQUE

The aim of this study was to gain the knowledge about kinematic and technical parameters required for acceleration of whole body in rotational shot put technique, using three-dimensional motion analysis. 12 male shot putters participated this study. From the results, linear momentum during double support phase (DSP) (r = 0.64, 0.79, p \u3c 0.05, 0.01) and angular momentum during flight phase (FP) and 2nd single support phase (SSP2) (r = 0.58-0.72, p \u3c 0.05, 0.01) were closely related with throwing record, and these parameters would indicate the acceleration of whole body. In addition, path length of center of gravity at DSP related with linear momentum (r = 0.75, p \u3c 0.01). And the velocity of right toe, right elbow and left heel were closely related with angular momentum during FP and second single support phase (SSP2). These results can be concluded that enhancement these parametars will be effective techniques for acceleration of whole body

CLASSIFICATION OF THE DISCUS THROW TECHNIQUE

The purpose of this study is to classify discus throwers based on the velocity components at release and to investigate their throwing biomechanics. Forty-six male discus throwers were classified into 2 groups through cluster analysis. Twenty-two throwers were classified into a horizontal dominant group, while the remaining 24 throwers were classified into a vertical dominant group. There were no significant differences in the throwing distance and resultant release velocity between the groups. The right leg angle at release and the displacement of the centre of gravity (vertical direction) were significantly greater in vertical dominant group. These results indicated the horizontal dominant group drove their right leg forward to increase the horizontal velocity, while the vertical dominant group lifted their body upward direction to increase the vertical velocity

Likelihood-Based Inference for Discretely Observed Birth-Death-Shift Processes, with Applications to Evolution of Mobile Genetic Elements

Continuous-time birth-death-shift (BDS) processes are frequently used in stochastic modeling, with many applications in ecology and epidemiology. In particular, such processes can model evolutionary dynamics of transposable elements - important genetic markers in molecular epidemiology. Estimation of the effects of individual covariates on the birth, death, and shift rates of the process can be accomplished by analyzing patient data, but inferring these rates in a discretely and unevenly observed setting presents computational challenges. We propose a mutli-type branching process approximation to BDS processes and develop a corresponding expectation maximization (EM) algorithm, where we use spectral techniques to reduce calculation of expected sufficient statistics to low dimensional integration. These techniques yield an efficient and robust optimization routine for inferring the rates of the BDS process, and apply more broadly to multi-type branching processes where rates can depend on many covariates. After rigorously testing our methodology in simulation studies, we apply our method to study intrapatient time evolution of IS6110 transposable element, a frequently used element during estimation of epidemiological clusters of Mycobacterium tuberculosis infections.Comment: 31 pages, 7 figures, 1 tabl

CADLIVE Optimizer: Web-based Parameter Estimation for Dynamic Models

Computer simulation has been an important technique to capture the dynamics of biochemical networks. In most networks, however, few kinetic parameters have been measured in vivo because of experimental complexity. We develop a kinetic parameter estimation system, named the CADLIVE Optimizer, which comprises genetic algorithms-based solvers with a graphical user interface. This optimizer is integrated into the CADLIVE Dynamic Simulator to attain efficient simulation for dynamic models