藤戸 靖則

This study aimed to determine the cause of the sticking region (SR) that occurs in the back squat (BS) from biomechanical analysis. Six male college weightlifters (age：20.5±2.2 years, height：173.4±7.6 cm, weight：79.3±16.9 kg, 1RM：149±27.4 kg) performed one rep. with different loads (0, 30, 50, 70, 90, 100% 1RM) and BS without counter movement (0, 30, 50, 70, 90%1RM) for one rep. followed by BS exhaustion trial at 70%1RM. We calculated barbell velocity, joint angles, angular velocity, moments, and power in the lifting phase. Identification of SR became more pronounced with increased loading. In SR phase during BS, ankle plantar flexion angular velocity and power and knee joint extension angular decreased. On the other hand, knee joint extension power decreased in the middle phase. These results suggest that the appearance of SR might be related to moment and power attenuations in knee joint during BS exercise.

The purpose of this study was to clarify the reaction times of karate athletes against opponents based on kinetics and kinematics in karate kumite. In addition, the reaction times of international, university and kata athletes are compared to examine the characteristics of international-level athletes. Thirteen female university karate athletes (kumite international level：n＝2, kumite university level：n＝6, kata：n＝5) participated in this study. Fourteen motion capture cameras and three force plates were used to record kizami-tsuki and gyaku-thuki movements to LED light stimuli and the opponent’s movement. Kinetics and kinematics analysis showed no differences in reaction times od LED light stimuli between kumite, kata and competition levels. But international level kumite athletes tended to have the shorter reaction times against opponent’s movement. In conclusion, these results suggest that kumite international level athletes have an excellent ability to predict and estimate the movements of their opponents.

J-GLOBAL ID : 201101073728331279 J-GLOBAL ID : 201801007052633411 J-GLOBAL ID : 202201012804701108 J-GLOBAL ID : 201801009314123820 J-GLOBAL ID : 202101004237845144 The purpose of this study was to analyze the kinematics and kinetics of how karate players respond to LED light stimuli and opponents when performing kizami- and gyaku-tsuki. The effects of the distance between the attacker and the opponent, and the differences in event types and levels on the reaction time were also examined. Thirteen female university student karate athletes （kumite international level：n＝2, kumite college level：n＝6, kata：n＝5） participated in this study. Fourteen motion capture cameras and three force plates were used to record kizami-tsuki and gyaku-tsuki movements to LED light stimuli and the opponent. Kinetics and kinematics analysis showed no difference in reaction time to LED light stimuli among kumite, kata, and competition levels, but international level kumite athletes tended to have the shorter reaction time to opponent's movements. In conclusion, our results suggest that international-level kumite players have an excellent ability to predict and judge the movements of their opponents. 1520297128939472640 application/pdf

J-GLOBAL ID : 202201012804701108 J-GLOBAL ID : 202301019486094800 J-GLOBAL ID : 200901085265547080 J-GLOBAL ID : 202101004237845144 The purpose of this study was to clarify the effects in the lower hip angle in different back plate positions has on the times of the 5 m and 10 m of a swim start. Seven male Japanese swimmers including national level athletes were selected as subjects. Each swimmer participated in three back plate positions；each dive using a different back plate position and recordings of time from the start to 15m were made. 10 motion captured systems were used to capture kinematics data, and two video cameras measured the time at each passing point. The results of this study showed that the 10m time was significantly shorter in the order of Front, Prefer, and Back. There was no difference in the take-off horizontal velocity, but the 10m time resulted to be shorter when the take-off angle was higher. The farther the distance between the back plate, the larger rear foot hip angle at the kick start stance of the start, and the earlier the start of extension of each joint angle. It is considered that this makes it easier to raise the upper body, which enables horizontal movement and increases the speed of the 10m time. 1520860078898196096 application/pdf

J-GLOBAL ID : 201301090685531402 J-GLOBAL ID : 201801009314123820 J-GLOBAL ID : 202101004237845144 The purpose of this study was to compare the differences in mechanical power and physiological intensity during high intensity intermittent exercise on a bicycle ergometer by wrestlers of different performance levels. Three members of a collegiate wrestling team participated in (1) incremental load test to determine aerobic work capacity (VO_2max), (2) a maximal anaerobic power test and a 90 second Wingate test to determine anaerobic work capacity, and (3) high intensity intermittent exercise (20 sec × 8 sets, 170% VO_2max) on a bicycle ergometer. Bicycle ergometer was used for all the tests. Mechanical power output, oxygen uptake, and heart rate were measured during all tests. Oxygen uptake and heart rate were recorded over time during the recovery period only after the completion of high intensity intermittent exercise. As a result, the ratio of power output of each athlete was calculated. Athlete A was able to perform at least 100% until the third set, B the fourth set, and C the third set. The average power of A (6.3 W/kg) and B (5.7 W/kg) tended to be higher than that of C (4.3 W/kg). Athlete B (9.6 ml/kg/min) had the lowest oxygen uptake at 2 min post-exercise, while A (12.8 ml/kg/min) and C (12.8 ml/kg/min) showed no significant differences. Athletes with superior anaerobic and aerobic work capacity among wrestlers did not exhibit higher mechanical power output during high intensity intermittent exercise, and athletes with superior wrestling athletic performance tended to have smaller repetitions of high intensity intermittent exercise and smaller reduction rates during exercise. 1520860078896017792 application/pdf

本研究の目的は，日本代表選手を含む大学アルペンスキー選手の体力測定値とパフォーマンスの関係性を検討し，その測定値の有効性と世界一流選手（World）と大学アルペンスキー選手（College）の体力レベルの差を明らかにすることでトレーニングへの一助とすることを目的とした。被験者は，17名の日本代表選手を含む大学男子アルペンスキー選手（Collage）であった。測定項目は，形態・身体組成，柔軟性，筋力，非乳酸性パワー，乳酸性パワー，そして有酸素性パワーの測定であった。アルペンスキー競技のパフォーマンスには，国際スキー連盟（FIS）が定めるFISポイント（回転，大回転，スーパー大回転）を採用した。体力測定項目とFISポイントの関係性には，ピアソンの積立相関係数およびスピアマンの順位相関係数を用いて評価した。また，CollageとWorldの体力の差の検討には，先行研究Neumayr et al.（2003）の報告を参考した。FISポイントと体力測定値の関係性は，形態・身体組成と柔軟性以外の全ての項目と有意な負の相関関係がみられた。FISポイントとの関係性がみられた膝屈曲トルクは，WorldがCollageより大きな値を示し、最大43％の差であった。その次に大きな差がみられた測定項目は，2 mmol/lの相対的な有酸素性パワーであった。大学生アルペンスキー選手の膝伸展屈曲トルク，非乳酸性パワー，乳酸性パワーおよび有酸素性パワーの体力要素は，アルペンスキー競技パフォーマンスと有意な相関関係が認められ，世界レベルを目指すための体力トレーニングの目標値が示された。 原著論文