本研究は一般男子げ選手2 名を対象として，高重量やりトレーニングが正規重量やりの投てき距離に及ぼす影響を，動作パターンや練習内容の要因から検討し，トレーニングへの示唆を得ることを目的とした．そのため， 900g の高重量やり（NT4582B，NISHI 社製）を用いたトレーニング期間を12 週設け，トレーニング期間の前後には正規重量やりによる投てき距離の測定を行った．その結果，高重量やりを助走投げに用いた対象者A は，ブロック動作に習熟し，下肢から体幹への運動連鎖が改善された他，リリースまで体幹長軸回転が継続するように投てき動作が変化したことで，投てき距離が1.62 m 増加した．一方，高重量やりを助走練習と立投げのみに用いた対象者B では，助走速度が顕著に増加したが，左足接地時のためが消失したために，投てき距離が1.47 m 低下した．これらのことから，高重量やりを助走投げに用いることは，下肢から体幹への運動連鎖に課題を抱える選手や，リリース時の体幹長軸回転に課題がある選手にとって有効であることが示唆された

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Athletic performance in javelin throw is affected by various characteristics of the javelin. In this paper, four different types of javelins are investigated using the technique of modal analysis, and are thrown by eight javelin throwers. The effect of dynamic characteristics of the javelin on the athletic performance is discussed. There are no differences in the static characteristics among the four javelins, but their dynamic characteristics are different in the resonant frequency, the dynamic compliance, the logarithmic decrement and the moment of inertia. It was found that the dynamic characteristics of the javelin affected the athletic performance in javelin throw. The rate of influence in terms of the thrown distance is about two to three percent.

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　The purpose of this study was to investigate motion factors in female javelin throwers during success and failure trials from a biomechanical standpoint. Fourteen throwers who participated in the Japanese Women’s Javelin Championships Final were investigated during both success trials and failure trials and the results were compared. The success trial was set as the best record and the failure trial as the worst record. Timing points of throwing motion were set at right foot contact (R-on), left foot contact (L-on) and javelin release (REL). The main results were as follows;
　1) There was no significant difference in approach velocity between the success and failure trials.
　2) In the success trials, peak speeds of the right shoulder, elbow joint and javelin were higher than those in the failure trials.
　3) In the success trials, the left rotation velocity of the shoulder angle was larger than that in the failure trials just after L-on.
　4) In the success trials, the forward rotational velocity of the trunk was larger than that in the failure trials just after L-on.
　5) In the success trials, the throwers maintained a more extended position of the left knee angle than in the failure trials between L-on and REL.
　These results revealed that superiority or inferiority for female javelin throwers at the same competition level was determined not by the approach velocity, but by the blocking motion of the left leg. Although the importance of this left leg blocking motion has been reported many times in previous studies of throwers with different performance levels, it has been shown here to play an important role in the success of individual performance.

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　The javelic ball throw using a JaveBall is a track and field event designed for elementary schoolchildren and is regarded as an introduction to the javelic throw, an event for junior high school students, which in turn is an introduction to the javelin throw, an event for high school students and beyond. This study examined the effect of release parameters on flight distance in the javelic ball throw. Flight distances and release parameter values of 146 throws by 17 participants were measured. Initial velocity was the parameter with the strongest influence on flight distance. Release angle, angle of attack, and horizontal angle of attack had some influence, but flight distance did not differ markedly even when the values of these parameters were very low or very high. The ratio of the actual flight distance to the theoretical flight distance decreased with increasing initial velocity, indicating that achieving a greater actual distance becomes more difficult as the release velocity increases. Although the rotational speed of the JaveBall around its longitudinal axis was a factor that reduced the actual flight distance relative to the theoretical flight distance regardless of its magnitude, it was considered that the decrease in the actual flight distance relative to the theoretical flight distance will decrease when an extremely small rotational speed is applied without reducing the initial velocity. Although the javelic ball throw is intended as an introduction to the javelic throw, which in turn leads to the javelin throw, this study showed that the characteristics of the JaveBall are not necessarily similar to those of a javelin, for which the rotational speed increases relative to the increase in initial velocity. Athletes and their coaches should be aware of this if they expect to transition from the javelic ball throw to the javelin throw in the future.

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This study was conducted to investigate the kinematic characteristics of javelin throw for further comprehension of the techniques and mechanics of the javelin throw. Forty-nine male javelin throwers were videotaped, using two 200 fps high-speed video cameras in three athletic competitions.

The results revealed the significant positive correlation between the initial velocity of javelin and the throw distance (r = 0.797, p < 0.001). The throwers showing the higher initial velocity of javelin showed the higher forward rotation angular velocity of trunk at the moment of javelin release (r = 0.484, p < 0.001). The elbow joint angle and shoulder abduction angle at the moment of javelin release showed the significant negative correlations with the initial velocity of javelin (r = -0.437, p < 0.01 and r = -0.454, p < 0.01, respectively). The velocity calculated by taking the shoulder velocity from the grip velocity at the moment of javelin release showed the significant positive correlation with the initial velocity of javelin (r = 0.819, p < 0.001). These results suggested that both extension and internal rotation of the shoulder contributed to the enhanced relative arm velocity for the elite throwers, while the internal rotation of the shoulder for the novice throwers limitedly contributed to it.

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The purpose of this study was to develop the evaluation standards for the throwing motion of male javelin throwers and to confirm the usability of these evaluation standards. The throwing motion of 91 male javelin throwers (from novices to the world champion) was analyzed by using three-dimensional motion analysis methods focusing on the preparation phase (from the final right leg contact (R-on) to the left leg contact (L-on)). The results of the multiple linear regression analysis that considered the throwing record to be a dependent variable and the throwing motion parameters to be the independent variables revealed that approximately 76% of the throwing record was determined by seven throwing motion parameters. These parameters were as follows: 1) the body center of gravity (CG) velocity, 2) horizontal length from CG to grip, 3) trunk angle (sagittal plane) at L-on, 4) left knee angle at L-on, 5) arm angle (angle between right shoulder-grip line and x axis) at R-on, 6) right knee angle at R-on, and 7) hip angular displacement (angle between right hip- left hip line and x axis) during the preparation phase. The evaluation standards for the throwing motion were determined by considering the average values, standard deviation, and standardized partial regression coefficient of the abovementioned seven motion parameters. These evaluation standards were able to evaluate a response to the longitudinal change in the throwing motion of a javelin thrower who went from being a high school top level to being the national top level.

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Kinetic analysis of javelin throwing has been a difficult subject, because the force applied to javelins is unknown and javelins are originally elastic. Therefore, a javelin with a 6-component force transducer is developed in the present reserch. The javelin is equipped with a thin pipe at the gripping position, and the pipe has elastic hinges to mesure the force by utilizing strain gages. The six components of the force applied to the javelin by one male javelin thrower is measured using the force transducer. The major results obtained are as follows; The javelin with the transducer is heavier in weight, and smaller in moment of inertia and in lower compliance at the grip as compared to the ordinary javelins. The measuring system developed is found to be satisfactory to measure the forces in javelin throw, since the relation between the measured voltages and applied forces is linear, and the resonant frequency of the transducer is higher than that of the force measured during actual javelin throw. As a result of a measuering experiment, the force components change mainly from the moment when the thrower stepped his right foot on the ground to release the javelin after run and crossover-step. The peeks of the force components apeared just before the release, and the maximum values are 14.00 kgf in the axial direction of the javelin, 7.21 kgf, 4.62 kgf in the lateral directions, 0.12 kgf・m around the axial direction, and 0.64 kgf・m, 0.77 kgf・m around the lateral directions.

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　The purpose of this study was to investigate whether gender differences in motion factors affect throwing record in the javelin throw. Data on javelin throwing motion were collected from 91 male and 81 female right-handed javelin throwers covering a wide range of levels during several competitions (including the gold medalist at the 2007 IAAF World Championships in Osaka). The throwers and javelin movements were recorded with 2 cameras at 60 fps, and three-dimensional coordinates were calculated using Direct Linear Transformation (DLT). The throwing motion timing points examined were the final right foot contact (R-on), the left foot contact (L-on), and the release of the javelin (REL). Moreover, the period between R-on and L-on was considered the preparatory phase, and that between L-on and REL the throwing phase. The main results were as follows: (1) Females showed a slower center of gravity velocity than males at all time points. (2) At L-on, females showed greater left rotation of the shoulder and hip angle (in the trunk open state). (3) The shoulder rotation angle of females at L-on showed a significant positive correlation with the throwing record. These results suggest that the characteristics of throwing motion in females differ from those of males. The torso of female javelin throwers showed greater left rotation than that of males in the preparatory phase, suggesting that there are gender differences of motion factors in the javelin throw. These may be attributable to gender differences in physique, muscle strength, and joint laxity.

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In order to improve the record of the javelic throw in the junior Olympic games, it is important to elucidate the flight characteristics of the “turbo-jav” used in this throwing event. Unlike the spear used in the javelin throw, the turbo-jav has four tail fins. Focusing on the effect of the fins, we investigate the flight characteristics of the turbo-jav, by means of wind tunnel tests, throwing experiments and numerical simulations. In the wind tunnel test, we measured the drag force, lift force and pitching moment acting on intact turbo-javs as well as turbo-javs with their fins cut, in a low speed wind tunnel at the flow speed up to 25 m/s. The experimental results showed that the drag and lift coefficients for the intact turbo-javs are larger than the corresponding values for the turbo-javs without fins. As the angle of attack increases from 0, the moment coefficients for the intact turbo-javs decrease from 0, whereas the moment coefficients for the turbo-javs without fins increase. In accord with this property for the pitching moment, the throwing experiments showed that intact turbo-javs fly stably with oscillating angle of attack around 0. The flying distance, the orbit and the variation of angle of attack for the intact turbo-javs launched by a launcher agree closely with the numerical simulation performed based on the wind tunnel test. A comparison of throwing experiments by an athlete and by the launcher suggested that the turbo-javs flying without rolling could reach farther than turbo-javs with rolling.

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It's effective in realization of a plain broadcast to indicate the track of flight objects like a ball, a javelin etc., in sports programs.. So, this time, we developed the javelin throw tracking system. It’s possible to display the curvature and the angle of the javelin throw, only to crick several points of javelin in the TV image.

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The present study focused on the behavior of the ball at the time of the stroke in soft tennis, and it aimed at exploring the relations of many kinematic values at impact, and the flight behavior of the ball, while checking whether there might be an abnormal flight behavior. The flight of the ball was videotaped by three sets of video cameras, and the ball at impact was videotaped with two high speed cameras. The behaviors of these balls were analyzed. These experiments investigated the conditions of the flights of soft tennis balls, both when given a lift from an applied drive rotation and when given a sinking flight from a slice rotation. It was suggested that the difference in rate of spin given by a stroke influenced the abnormal flight behavior of a soft tennis ball, and also that when there was drive rotation or slice rotation of 40rps or more, the possibility of abnormal flight behavior occurring was high.

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に関しては，大きな飛距離を獲得するための動作要因がこれまで系統的に明らかにされてきた．その一方で，その動作要因の獲得を実現するための身体の使い方に関する研究は，ほとんど見当たらないのが現状である．筋活動の様相を明らかにすることは，アスリートが実際にどのように身体を操っているのかを明らかにするための重要な情報となる．そこで本研究では，関節のキネマティクスと筋活動の関係から，投てき動作における上肢及び及びの筋活動の様相を明らかにすることを目的とした．男性競技者2名を(PB: A72.88，B:69.43)を被験者とし，試合形式の全力投てきを行わせた．3台のハイスピードカメラ（240fps，露出時間1/1000sec）を用いて投てき動作を撮影した．筋活動電位は導出部が直径4mmのAg-AgCl表面電極を用い双極導出法により導出した．被験筋は以下の10筋とした．右大胸筋胸肋部，右上腕二頭筋長頭，右上腕三頭筋長頭，右前鋸筋下部，右広背筋椎骨部，右僧帽筋横行部，右三角筋肩峰部，右棘下筋，右大円筋，右外腹斜筋．筋活動の分析の結果，活動の様相に個人差はあるものの両被験者に共通した筋活動のパターンとして，右足接地前の空中局面において棘下筋の顕著な活動がみられた．左足接地から最大外旋の区間については，最大外旋に向けて棘下筋の活動を強めていた．また，肩関節内旋筋群については，左足接地直前において，大胸筋が活動を開始し，その後最大外旋から内旋にかけて大円筋，広背筋が活動を高めていた．

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