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Copyright of PODIUM- Revista de Ciencia y Tecnologia en la Cultura Física is the property of Universidad de Pinar del Rio and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed at identifying the most common sports injuries among the athletes of jumping in athletics in Amman as well as identifying the most common body sites that are exposed to sports injuries and the causes leading to sports injuries among the athletes of jumping in athletics in Amman. The researcher used the descriptive approach due to its compatibility to the study nature. The study also used the questionnaire as the study instrument for data collection. The study sample consisted of (23) athletes who were selected purposively. The researcher used (SPSS) to analyze the study data. The results revealed that the most common sports injuries among the athletes of jumping in athletics in Amman are myorrhexis, the most common anatomical sites of sports injuries among the jumping athletes in athletics are the knee joints and the most common causes for the occurrence of sports injuries among the jumping athletes are related to overtraining. The researcher recommended the necessity of conducting further studies that include the athletes of throwing and other events, especially the hammer throw. [ABSTRACT FROM AUTHOR]

Dynamically manipulating flexible objects using robots is difficult. Some studies have been conducted that only considered one type of object with known properties or that needed an identification test for string properties in advance. We propose a method to realize the dynamic manipulation of a string with unknown characteristics. We use a mass-spring-damper model for the string and repeat three steps: motion generation, real manipulation, and parameter estimation. The proposed method estimates the string properties to realize the motion objective via the real manipulation of the string. An identification test in advance was not necessary. In this study, we focus on swing manipulation. This can increase the motion energy of a string without a high-power actuator. After making a large swing, the robot can throw strings to a more distant target, such as a hammer throw. This motion is useful for explanation robots, rescue robots, and so on. We modified the proposed method to generate a swing manipulation. Then, we investigate whether swing manipulation can be performed by the proposed method and demonstrate its effectiveness via experiments with various strings with unknown characteristics. [ABSTRACT FROM AUTHOR]

The hammer throw is perhaps one of the most misunderstood and difficult events to learn in track and field. Improvements in technique are focused on strategies designed to increase implement release velocity. The purpose of this cross-sectional investigative study was to examine the association between the angle of separation between the thorax and pelvis and performance in the hammer throw. Two male and four female throwers were used to assess positional data of the hammer, thorax, and pelvis. Hammer positional data were used to determine linear hammer speed at release, release angle, and release height. Thorax and pelvis positional data were used to determine thorax rotation relative to the pelvis (separation angle). The association between values of separation angle at key instances and performance was examined. Performance was determined by distance thrown (55.69 ± 3.42 m). Release speeds (24.32 ± 0.70 m/s) were also examined as a contributory factor towards performance and were included to account for instances where throwers released the hammer using sub-optimal release heights and angles which negatively affected distance thrown. The separation angle at its smallest within each turn was found to have a strong negative association with the performance indicators, especially in the first two turns (significant correlates ranged from −0.82 to −0.97). This finding indicates when throwers reduced the separation to a smaller value, performance was enhanced. Separation angle was at its smallest in double support. This suggests that throwers may improve performance by reducing the separation angle during double support phases. [ABSTRACT FROM AUTHOR]

This paper examines the dynamic behaviour of square tubular T-joints under impact loading by means of experimental, numerical and analytical studies. Firstly, a high-performance drop hammer setup is employed to carry out the impact tests on five hot-rolled square tubular T-joints with different chord thickness and width ratio of brace/chord under three levels of impact height. The dynamic responses of tubular T-joints including the deformation patterns and the development of impact force and displacement are described. Based on the experimental results, the impact load-deformation relationships as well as the energy dissipation are further discussed to reveal the mechanical behaviour of T-joints, with emphasis on the effect of width ratio of brace/chord and impact energy. Complementary finite element model for simulating the tubular T-joints under impact is then proposed and validated against the available test results. Finally, the test results and numerical simulations are utilized to investigate the failure mechanism of T-joints under impact load. In particular, the local and global displacements of square chord are estimated by an equivalent area method, and the impact resistance of impacted joints is examined based on the yield line theory. In general, the investigation in this paper can also offer reliable test data and design suggestions to reasonably evaluate the impact behaviour of square tubular T-joints. [ABSTRACT FROM AUTHOR]

Aim. Study bibliography. The collection and tabulation of the following parameters: performances, age, height and weight on the first 100 hammer throw athletes seniors outdoors all time. Processing statistical and mathematical data specified above, regarding the following indicators: number of cases, maximum value, minimum value, amplitude, mode, median, average, quartile 1, 3, quartile difference, dispersion, average of absolute deviation, standard deviation, coefficient of variation and correlation. Evaluation of the results and their interpretation. Methods. As a research method we have used the case study, observation, statistics and graphics. Results. After data processing have resulted 2 summary tables and 4 graphs. Conclusions. The average performances is 82.45 m for men and 72.68 m for women. The average age is 28.63 years for men and 26.54 years for women. The average height is 188.03 cm for men and 175.60 cm for women. The average weight is 112.09 kg for men and 84.81 kg for women. [ABSTRACT FROM AUTHOR]

Copyright of Dirasat: Educational Sciences is the property of University of Jordan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Dirasat: Educational Sciences is the property of University of Jordan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hammer-throw has a long-standing history in track and field, but unlike some other sports events, men's hammer throw has not seen a new world record since 1986. One of the possible reasons for this stagnation could be the lack of real-time biomechanical feedback training. In this study, we proposed to establish scientifically described training targets and routes, which in turn required tools that could measure and quantify characteristics of an effective hammer-throw. Towards this goal, we have developed a real-time biomechanical feedback device-a wireless sensor system-to help the training of hammer-throw. The system includes two sensors-an infrared proximity sensor for tracing the hip vertical movement and a load cell for recording the wire tension during a hammer-throw. The system uses XBees for data transmission and an Arduino processor for data processing and system control. The results revealed that the wire tension measurement could supply sufficient key features for coaches to analyze hammer-throw and give real-time feedback for improving training efficiency. [ABSTRACT FROM AUTHOR]

The purpose of this case study was to describe the integration of sport science and coaching that helped to produce an American junior record of 68.12m in the women's hammer throw in 2012. Two digital video cameras (Canon Elura 60) running at 60 Hz were placed to view Shelby Ashe's best throws at the 2010 USATF Nationals (61.77 m), 2011 USATF Junior Nationals (58.34 m), and 2012 USATF Junior Nationals (68.12m American junior record). Following each competition, the coach collaborated with the sport scientist and chair of USATF coach's education to review and evaluate each of the throws. The record setting throw by Ashe was 1.49 s in duration from right foot lift off and produced a release velocity of 26.8 m/s. During the throw, Ashe spent 50.35% of the duration of the throw in double support. Improvements in technique focused on strategies designed to increase velocity of the head of the hammer. [ABSTRACT FROM AUTHOR]

Copyright of Sport & Society / Sport si Societate is the property of Altius Academy Foundation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim. We may wondered to our self in which measure these two probes 30 m sprint and pushed from lying down position are relevant for prognosis of the competitional results in hammer throwing and weight throwing probes. We consider that the statistic correlations are nonlinear, meaning that the veracity of the probes and control norms depending on the athletes performance, on ages or level training and in the last instance on probe it-self. Methods. Were taken into consideration the results of the control probes, sustained with three weeks before and, have correlated statistic labeled with the results from sportive competition. Were four athletes at hammer throwing and nine at weight throwing (men and women) from the representative lot of Romania. Results. For the 30 m sprint probe do not identified the significant correlations, the fact which limit the discussion of these probe utility at prediction of one result in competition but even of an effort capacity diagnosis or the training level, eventual the body state. The graphic-analytical and statistic processing of the pushed lying down probe shows that this control probe is significant correlated with competition result and that may be taken in the calculation of prognosis of proximal contest result. Conclusion. The pushed lying down probe show that this control probe is significant correlate with competition result and that may be taken into calculation of prognosis of the proximal contest result at weight throwing. Between the genuflections probe with barbell and the competition result of the man spear throwers the correlation items indicate a lower value (r=0.28). Therefore knowing the value of this probe can not make a prediction of the result from next competition. The result of this probe may offer us the structured and easy information in connection with: the diagnosis of the training level in different stages. [ABSTRACT FROM AUTHOR]

Objective. Functional strength training has become a popular buzzword in the fitness industry. Unfortunately, it is also subject to wide interpretation. At the extreme, some individuals believe that by mimicking the explosive, ballistic activities of high-level competitive athletes, they are training in a functional manner. All too often, however, such training programs greatly exceed the physiological capabilities of the average exerciser, which ultimately increases the possibility that an injury might occur. Most would agree that there is nothing functional about sustaining an injury due to improper training. In many respects, functional strength training should be thought of in terms of a movement continuum. The aim of this study was to investigate that Effect of functional strength training on certain physical variables for female college students. Methods. Twenty female students from Second Grade at the Faculty of Physical Education for Girls, Helwan University for the academic year 2013/2014 AD, divided into (2) group. The experimental group (n = 10) performance functional strength training and control group (n = 10) performed traditional exercise. Subject's parents and coaches were required to read and complete a health questionnaire and informed consent document; there was no history of injuries, diabetes or recent surgery. Results. The experimental group had significantly higher than the control group in core stability test, balance. In addition, No significant difference was found between the experimental group and the control group in power and strength. Conclusion. Under the condition of our study, functional strength intervention for eight weeks has a beneficial effect on core stability test, balance of hammer throwplayers. [ABSTRACT FROM AUTHOR]

Abstract: The hammer throw in athletics has been the subject of published research since the 1980s. This has focused on case studies of individual athletes or small cohorts and has identified a number of key performance indicators such as the speed profile of the hammer during the wind-up phase. To use these key performance indicators with current athletes a bespoke analysis tool is required for frequent data collection. An unobtrusive two cameras system was proposed and a non-standard planar calibration method that allows the safety cage to remain in place was designed. The performance of the non-standard calibration method was compared to the standard calibration method using simulated data. The non-standard method was found to be suitable when intrinsic camera parameters were not recomputed. The method is a suitable alternative for volumes that cannot easily be accessed with a calibration object or volumes that are too large for practically sized calibration objects [Copyright &y& Elsevier]

This paper is an observational study conducted between February and March 2012, on 14 Romanian athletes (hammer throwers) and 12 Romanian coaches, regarding the importance and use of the verbal and nonverbal communication during training and competitions. The study tried to confirm two hypotheses. We used as a research method the inquiry, represented by a questionnaire with 6 questions, on which each coach had to choose one answer. The analyzed answers have emphasized aspects that show the opinion of hammer throw athletes and coaches regarding the verbal and nonverbal communication. Their opinions reveal us that in training, there are small differences in the way in which the communication between the hammer throwers and their coaches is done. The athletes communicate 52.14% nonverbally, through gestures and facial expressions, and 47.86% verbally, while the coaches communicate 5 0.83% nonverbally, and 49.17% verbally. During athletic competitions, the throwers and the coaches communicate more nonverbally, 66.43% and 75.83%, respectively, than verbally, 33.57% and 24.17%, respectively. Outside their athletic 4fe, the throwers communicate verbally with their coach more by phone (76.43%) than by written messages (on the Internet, or phone) (23.57%), while the coaches verbally communicate with the athletes orally in proportion of 85.83%, and use written verbal communication in proportion of 14.17%. Fatigue, noise, and weather represent over 50% of the total perturbing factors for the athletes, while the coaches perceive the athlete's tension, nervousness that leads to bad performances, and the athlete's fatigue, as representing over 50% of the total perturbing factors. The communication process is perturbed "most times" by distance and position in proportion of 57.14% for athletes, and in proportion of 58.33% for coaches. The first hypothesis, stating that the hammer throwers use the verbal communication and the nonverbal communication in different proportions during training than during competitions, was confirmed, just as the second hypothesis, stating that the nonverbal communication is used more than the verbal communication by the hammer throwers and their coaches, during training and competitions, was also confirmed. [ABSTRACT FROM AUTHOR]

This study is observing the changes in the performance of male hammer throwers from 1980 to 2011. In order to explore these alterations, the performance of certain throwers (placing 1st, 5th, and 10th) in the world ranking list and the average result of the top ten were analysed. The factors directly influencing changes in the performance of hammer throwers were also investigated. In the 1980s the increase in the performance of hammer throwers was followed by a sharp decline. This is true for the athletes occupying different positions in the world ranking list, and for the average of the top ten throwers as well. According to our investigations and observations, performances increased in the second half of the 1990s, and after the turn of the 20th. century, a newer, well-documented increase can be observed, although this does not reach the peak level of 1988. It is a pity that the trends show a slight decrease in the second half of the decade, dropping to the averages experienced at the beginning of the 1980s. Without going into an in-depth analysis of the technical innovations of the 1980s, some important things have to be emphasised (in case of right handed thrower): the effort to increase the radius of the hammer's trajectory with the "counterweight" technique; the proportion of the two-leg support in turn was increased, with the help of a delayed "lifting off" and the early planting of the right leg; the thrower does not aim to precede the movement of the hammer and does not move ahead of the hammer, as could be seen in previous techniques. Instead of, he drives the hammer with his whole body; the lifting work of the legs plays a determining role in the two-leg support phase during the acceleration of the hammer. We think, besides these technical innovations, another important factor related to improving results are conditioning abilities; the development of the maximum and speed strength to a very high level in harmony with technical elements. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of early training for developing evidence-disposal or throwing techniques in athletes. In the study, teaching experiments using technical training for throwing spear, hammer, and disc was given to children aged 8-10 years. It concludes that early training can be used in the preparation of throwers and discusses the benefits of technical training based on objectives in the acquisition of basic mechanism in javelin and disc throwing technique.

The article discusses findings of a study which investigated the variables that contributed to maximum throwing distance in a collegiate hammer throw event in the U.S. Using a heavy steel ball attached to a wire and handle with a maximum length of four feet, the hammer throw requires the combination of strength, balance, timing and the use of near-perfect technique. The required weight of outdoor competition hammers are noted. The significant biomechanical factors for long throws are the velocity, angle of release and height of release.

Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3.9kg vs. 62.7 ± 5.1kg (p < 0.01). The percentage area of type II muscle fibres was 66.1 ± 4% in hammer throwers and 51 ± 8% in the control group (p < 0.05). Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm2, p < 0.01). Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p < 0.05). These data indicate that hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. [ABSTRACT FROM AUTHOR]

The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N. [ABSTRACT FROM AUTHOR]

The article presents a study to calculate the venue-induced effects of gravity and air resistance on the flight of a hammer. It only considered these effects on 95-mm diameter hammers for women and 110-mm diameter hammers for men, as they are more commonly used, but the principles discussed will relate to any legal hammer. Often, air resistance and varying gravity throughout the earth are not considered when throwing implements as massive as the hammer. Due to the relatively high velocities and flight times, it is reasonable to assume that significant venue-induced effects could result from local variances of gravity and air densities. These implied venue effects are worthy of investigation. Non-venue effects also dictate the distance a hammer will travel. The study found that temperature has only a small effect on the distances of hammer throws. Altitude and latitude have a larger effect but not large, in fact, smaller than the effect of moderate winds. Because wind speeds are not measured for hammer throws, it would make little sense to adjust for altitude and latitude in the hammer throw distances, when it is not possible to adjust for wind.

The aim of this study was to determine how much the predicted distance of a hammer throw is affected by (1) ignoring air resistance and (2) assuming that the centre of mass of the hammer coincides with the centre of the ball. Three-dimensional data from actual throws (men: 72.82±7.43 m; women: 67.78±4.02 m) were used to calculate the kinematic conditions of the hammer at release. A mathematical model of the hammer was then used to simulate the three-dimensional airborne motion of the hammer and to predict the distance of the throw. The distance predicted for vacuum conditions and using the ball centre to represent the hammer centre of mass was 4.30±2.64 m longer than the official distance of the throw for the men and 8.82±3.20 m longer for the women. Predictions using the true centre of mass of the hammer reduced the discrepancy to 2.39±2.58 m for the men and 5.28±2.88 m for the women. Predictions using air resistance and the true centre of mass of the hammer further reduced the discrepancy to -0.46±2.63 m for the men and 1.16±2.31 m for the women. Approximately half the loss of distance produced by air resistance was due to forces made on the ball and the remainder to forces made on the cable and handle. Equations were derived for calculation of the effects of air resistance and of the assumption that the centre of mass of the hammer coincides with the centre of the ball, on the distance of the throw. [ABSTRACT FROM AUTHOR]

On the rotating Earth, in addition to the Newtonian gravitational force, two additional relevant inertial forces are induced, the centrifugal and Coriolis forces. Using computer modelling for typical release heights and optimal release angles, we compare the influence of Earth rotation on the range of the male hammer throw and shot put with that of air resistance, wind, air pressure and temperature, altitude and ground obliquity. Practical correction maps are presented, by which the ranges achieved at different latitudes and/or with different release directions can be corrected by a term involving the effect of Earth rotation. Our main conclusion and suggestion is that the normal variations of certain environmental factors can be substantially larger than the smallest increases in the world records as acknowledged by the International Amateur Athletic Federation and, therefore, perhaps these should be accounted for in a normalization and adjustment of the world records to some reference conditions. Although this suggestion has certainly been made before, the comprehensiveness of our study makes it even more compelling. Our numerical calculations contribute to the comprehensive understanding and tabulation of these effects, which is largely lacking today. [Copyright &y& Elsevier]

While both discus and hammer throwing involve rotating movements resulting in the throw of an object, discus throwers sometimes report dizziness, a condition never experienced by hammer throwers. We investigated whether this susceptibility was related to the sensitivity of the thrower or to the type of throwing achieved. For the latter, we compared the determining features of gesture, gaze stabilization and projectile trajectory in both sports. A total of 22 high-level sportsmen in these 2 disciplines, half of them practising both sports, were interviewed. Slow motion video recordings of discus and hammer throwing were examined to determine the visual referential, head movements and plantar surface support area involved at each stage of the motions. Discomfort was reported by 59% of the sportsmen while throwing discus, but by none while throwing hammer. Because several individuals practised both sports, these results exclude the hypothesis of individual susceptibility to dizziness. Video analysis evidenced that during hammer throwing, visual bearings can be used more easily than during discus throwing. Moreover, there is a loss of plantar afferents and generation of head movements liable to induce motion sickness, such as Coriolis acceleration. In conclusion, although hammer and discus throwing present numerous similarities, we demonstrate here that crucial differences in the specific execution of each sport are responsible for the dizziness experienced by discus throwers. [ABSTRACT FROM AUTHOR]