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

COULD PLAYING SURFACE INFLUENCES CHANGE OF DIRECTION AND PERCEIVED TRACTION PERFORMANCE IN FUTSAL?

The purpose of this study was to identify differences on change of direction performance, perceived traction performance and available friction coefficient between two different futsal playing surfaces. Functional test and perceived traction evaluation were performed by twenty experienced male university level soccer players using slalom course on two different playing surfaces (area-elastic:AE and point-elastic:PE). Available friction coefficient (AFC) for each playing surface was mechanically measured using a hydraulic-powered moving force platform. In the functional test, participants were found to perform significantly better on PE when compared to AE surface (p\u3c0.001). PE surface was also found to have higher perceived traction performance (p\u3c0.001). It was suggested that significantly higher AFC observed on the PE surface compared with AE surface (p\u3c0.001) may contribute to the observed findings. This study succeeded in demonstrating the performance of change of direction run was significantly influenced by the playing surface traction and frictional properties

COMPARISON OF SUCCESS AND FAILURE IN SOCCER VOLLEY KICKING

The purpose of this study was to describe kinematic variables that can distinguish between successful (straight to the goal) and failed (over the goal) soccer volley kicking. To mimic the situation of the volley kicking, the ball was set on a paper pipe. The kicking motions of both successful and failed trials were captured from ten male university soccer players using an optical motion capture system at 500 Hz. As a result, foot–ball impact points on the ball in failed trials were concentrated around the bottom part of the ball, and the kicking motion in failed trials were characterized as: 1) smaller hip internal rotation during the back-swing, 2) more upright foot posture at ball impact and 3) more downward leg swing just before ball impact. Furthermore, it was suggested that there were several patterns of failed trials depending on the subjects

Reliability of Zepp baseball on batting velocity / Raja Nurul Jannat Raja Hussain … [et al.]

In baseball and softball sports, one of the important characteristic of a successful hitter is having a fast bat swing velocity. Therefore, it is crucial to measure changes of batting velocity in training and during competitive matches. This paper quantifies the reliability of a small wearable sensor that was designed to be used in baseball and softball sports. An inertial measurement unit (IMU) manufactured by Zepp Lab, USA was used to measure the batting velocity in softball. A single female collegiate softball player completed sixty tee swings of two pre-determined swing velocities. Results from moderate velocity Vm (25.5 ± 3.5 m/s), and fast velocity range Vf (34.5 ± 3.5 m/s) were obtained. Data were collected concurrently with a 3- Dimensional (3D) motion analysis system (Qualisys Motion Capture). The reliability of the IMU was determined based on the Pearson Correlation and Intraclass Correlation (ICC) values between the IMU and the 3D data. Results indicated strong and moderate correlation between the IMU and the 3D data (Vm, r = 0.89; Vf, r = 0.59). The ICC for Vm (0.89) showed strong agreement, while fair agreement showed for Vf (0.37). However, for a total of sixty swings of two different velocities showed almost perfect agreement (ICC = 0.94). These results indicate that the Zepp Baseball device has an acceptable level of reliability in measuring batting velocity during different swing velocity ranges and it is suitable to be use in a softball-related research environment

フットサルにおけるフットウェアとコートサーフェイスとの相互作用の解明

福岡大学202

The Most Utilized Rotation and Translation Movement While in Ball-Possession among Futsal Players

AbstractThe objective of this study was to identify the most utilized rotation and traction related movements among international futsal players when they are in a ball possession situation. A total of 4 matches from The AFF Futsal Championship 2014 were analyzed. The analyzed matches consist of two semifinal matches, 3rd-4th placing match and the final match. There are four indicators for rotation movement (half-trunk rotation, half-body rotation, quick-half trunk rotation, and quick-body rotation) and four indicators for traction movement (front traction, back traction, side traction, and sudden stop) that are selected to be observed in this study. Each indicator was divided into two categories, which are attacking and defensive mode. All matches were recorded using a full high definition video camera and analyzed using SportCode Elite (v. 10) and Dartfish EasyTag (v. 1.0.8) software. Two trained and experienced analysts were assigned to analyze all 4 matches. Inter- and Intra- analyst reliability studies were also performed in order to examine the content validity of the data obtained. Overall results indicated that the front traction during the defensive mode is the most utilized movement, among others, while back traction during the attacking mode is the least utilized movement. Front traction during attacking mode was found to be the highest number of usage during attacking mode while sudden stop traction during defensive mode is the least utilized movement among other defensive movements. Regardless of attacking or defensive mode, results show that front traction is the most utilized movement, followed by half-trunk rotation and side traction. This study also show that the rotation (47%) and traction movements (53%) utilized during competitive games are quite balanced. A similar result was also obtained when comparing between attacking (46%) and defensive mode distribution (54%) from overall data. Further study on futsal games should focus on the most utilized movement during competitive matches to understand more about the nature of the games

Proceedings of the International Colloquium on Sports Science, Exercise, Engineering and Technology 2014 (ICoSSEET 2014)

XXIV, 647 p. 119 illus., 69 illus. in color.onlin

Measurement of Interaction between Futsal Footwear and Futsal Pitch Surface under Different Outsole Condition

The interaction between footwear and the pitch surface is an important aspect for successful performance and injury prevention in futsal. We aimed to investigate shoe-surface interaction of non-marking and multi-studded outsole designs. Five university players were recruited to perform two futsal specific movements (front translational traction-FTT and side translational traction-STT). A motion capture system including an embedded force plate covered by a synthetic material for futsal pitch, were utilized to collect the ground reaction force components. During FTT and STT, the multi-studded outsole was characterized by significantly higher mean peak traction forces. Moreover, although there were no significant differences in peak coefficient of traction between the two types of futsal shoes during STT, the multi-studded outsole tended to produce marginally higher peak coefficient of traction during FTT. It can be concluded that the multi-studded outsole design is prone to generate higher traction force and coefficient of traction