RELATIONSHIP OF MOTIONS BETWEEN THE ARM AND THE LEGS IN THE DIVING MOTION OF SOCCER GOALKEEPERS

The purpose of this study was to clarify the relationship between the hand movement of the goalkeeper (GK) and the velocity of center of gravity (CG) in diving motion towards various heights and distances. Three male university GKs dived towards the shot. Three male university forward players performed instep kicking to twelve shot areas by forward dribbling. Three-dimensional (3D) coordinates of the body landmarks and ground reaction forces were obtained with a 3D motion capture system and two force platforms. The novel findings in this study were summarized as follows: (1) GKs changed not only the height of their CG but also the motions of their trunk and arm according to the shot heights; (2) exerting elbow joint torques is important for GKs to dive towards the near upper and near middle places; and (3) it is assumed that not only accelerating the CG but also the trunk and arm motions are necessary for the evaluation of diving skills for GKs

BIOMECHANICAL ANALYSIS OF SAVING MOTION FOR SOCCER GOALKEEPERS FOCUSED ON THE FUNCTION OF LOWER EXTREMITIES

The purpose of this study was to clarify the function of the lower extremities during the saving motion of a goal keeper (GK). Eleven male university GKs dived toward a ball thrown 3.5 m ahead. Three-dimensional (3D) coordinates and ground reaction forces were obtained with a 3D motion capture system (250 Hz) and 2 force platforms (1000 Hz). The novel findings in this study are summarized as follows: (1) hip extension of the contralateral side leg to the ball is an important motion in the Pre phase and (2) exertion of extension torque at the hip in the early Transition phase has an important role for controlling backward leaning of the thigh during the saving motion

BIOMECHANICAL RELATIONSHIP BETWEEN THE GOALKEEPER’S MOTIONS AND THE KICKER’S MOTIONS IN SOCCER

The purposes of the study were (1) to identify the relationship between kicking motion of kickers and diving motions of goal keepers (GKs), and (2) to investigate the knowledge which can anticipate the moving direction after the preparatory motion from the kicking motion. Fourteen collegiate male GKs and 11 collegiate outfield players participated in this study. The mimic real shooting situation was captured with motion capture systems. The primary findings were: Regardless of the shot direction (rightward and leftward), the motion timing of preparatory motion is similar. The GKs started jumping at the same time as grounding of kicker’s support leg or immediately after hitting the ball. In addition, it is thought that the GKs have already judged the shot direction quickly while they were jumping because they had watched the kickers’ movement in approaching phase

CHARACTERISTICS OF THROWING MOTION OF OVERPOWERING FASTBALL COLLEGE PITCHERS

The purpose of this study was to compare the motion pattern of overpowering fastball pitchers. The throwing motion of eighteen male college pitchers were analysed using a motion capture system. This study focused on the movements of the pivot leg and the trunk during the preparatory phase. The overpowering fastball pitchers in the present study largely abducted the hip of the pivot leg and leaned the trunk toward the pivot leg during the preparatory phase. That these motions were seen during the preparatory phase would reveal that a key motion to get fast ball speed exist in the preparatory phase

ANALYSIS OF THE SERVING MOTION OF MALE COLLEGE TENNIS PLAYERS IN MATCHES.

The purpose of this study was to analyse and compare the serving motions of the fast hitters who can hit fast-ball in serve and normal Japanese male college players in matches. The variables used in this study were ball speed, racket speed, joint and segment angles of the shoulder, the torso and the limbs. Ball speed and racket speed for the fast hitters were significantly greater than that of the normal players. There were a significant differences between two groups in the angles of the shoulder and the knee joint. To improve the racket speed of the normal players, it is necessary to maintain the shoulder more horizontally abducted, the shank not too lean forward and the torso upright during the backswing, and to reduce the shoulder abduction during the forward swing

CHANGES IN THE THROWING TECHNIQUE OF COLLEGE MALE JAVELIN THROWERS BY AN IMMEDIATE FEEDBACK TRAINING.

The purpose of this study was to present effects of the immediate feedback training on techniques in college male javelin throwers. The participants were five college male javelin throwers. The technical problems revealed by the preliminary motion analysis were explained to the participants for this experiment. In the immediate feedback training, an iPad displaying the motion pattern of the ELITE throwers (Notomo et al., 1998) was set up, and a delayed playback device was used to allow the participants to visually compare their own movements with the model after throwing. Three trials were performed in each of before and after the training sessions. The best recorded trials in each of the training sessions were selected for analysis. Three of five throwers improved their deceleration of center of gravity and trunk rotation, although improvement in the record and the release speed of all participants was not observed

EFFECT OF A BlOMECHANlCAL FACTOR ON ENERGY EXPENDITURE BY DISTANCE RUNNERS DURING REPEATED VERTICAL JUMPS

This study aimed to clarify a biomechanical factor that would affect energy expenditure during repeated vertical jumps. The subjects, nine male Japanese distance runners, jumped for 3-min periods on a force platform under four different conditions. Motion and electromyography (EMG) data were recorded with a high-speed camera and surface electrodes, respectively. The following results were obtained: 1) the integrated EMG of the rectus femoris and vastus lateralis was greater in the Low and Decline conditions than in the High and Incline conditions, and 2) mechanical work at the ankle was greater in the High and Incline conditions than in the Low and Decline conditions. Thus, increased knee extensor muscular activity may increase the energy expenditure, and the stretch-shortening contraction of the gastrocnemius muscle may be more efficient

ANALYSIS OF THE SERVING MOTION OF MALE COLLEGE TENNIS PLAYERS IN A SIMULATED MATCHES

The purpose of this study was to analyse the serving motion of the nineteen male college tennis players in simulated matches, and to seek for critical points for the improvement in the techniques by comparing with that of the world-class players reported by Fleisig et al. (2003) and Michikami (2014). The variables used in this study were the ball speed, racket speed, angles and angular velocities of the upper and lower limbs. Ball speed and racket speed for the male college players were significantly lower than that of the world-class players. The peak angular velocities of the right shoulder internal rotation and the left knee extension were lower in the male college players than those of the world-class players. For the improvement in the ball speed in serve, the critical points identified would be large angular velocities of the shoulder internal rotation and the knee extension

ANALYSIS OF RUGBY PUNT KICK MOTIONS AIMING AT DIFFERENT KICKING DISTANCES

The purpose of this study was to compare the rugby punt kick motions for different kicking distances of college players, focusing on the motions of the kick leg and hip. A motion capture system (11 cameras, 200Hz) was used to collect three dimensional coordinates data of nine college rugby players, who performed three different punt kicks aiming at 35m, 50m and maximum kicking distances. Pelvis rotation range of motion and approach angle increased significantly with the increase in kicking distance. Significant correlations were found between the pelvis rotation range and swing speed (r=0.736,

<原著論文>大学選手およびV リーグ選手のバレーボールにおけるスパイクの打ち分け : A クイックに着目して

This study aimed to obtain useful suggestions for coaching, by clarifying the characteristics of changing the direction of A quick, by motion analysis. On applying motion analysis to a total of 6 middle blockers in university, or men`s V・ Challenge League specializing in quick attack, it was found that there was a difference in changing direction of A quick. This study obtained useful suggestions for coaching due to the above. To change the direction of A quick, there are three important methods: 1. changing direction by movement of the trunk rather than the shoulder joint, and shifting the impact point by half on the ball indirection in which the player wants to hit. 2. In case the player wants to hit the ball to cross, twisting the player’s body largely backward from takeoff to taking back and shifting the impact point to the right side, rather than hitting by turning, and stooping the trunk to transmit force to the ball for impact. 3. In case the player wants to hit the ball by turning, he does not twist his body backward from takeoff to taking back and shifting the impact point to the left side, rather than hitting to cross, without stooping the trunk in order to obtain space for swinging, and bending the trunk to the left, in order to transmit force to the ball