KINEMATIC COMPARISONS OF TAIWANESE AND VARIOUS FOREIGN VARSITY BASEBALL PITCHERS

The purpose of this study was to compare the kinematic the pitching motion between Taiwanese, Japanese, Cuban, and American collegeate pitchers (21.9±1y, 1.76±3.8m, 76.6±7.9kg). Kinematic data were analyzed for 10 Taiwanese baseball pitchers, and compared with advanced research by Shimada et al. (2012), Takahashi et al. (2005), Escamilla et al. (2001), and Fleisig et al.(1999). Taiwanese pitchers showed larger peak pelvis rotation angular velocity (Taiwanese: 844.1±215.5 deg/s, Others: 720.2±174.44 deg/s). and smaller rotation angle at release(REL) of Taiwanese pitchers (T: -88.6 ± 9.9 deg) was larger than that of foreign baseball pitchers (O: -92.9±9.3 deg). Due to the kinetic chain, Taiwanese pitchers were unable to transfer the kinetic energy from the lower body to the upper body, and then, they couldn\u27t increase ball velocity

KINEMATIC AND TEMPORAL CHANGES OF SLIDE STEP DELIVERIES OF BASEBALL PITCHERS DUE TO TECHNICAL TRAINING AIMING TO SHORTEN THE MOTION TIME

The purpose of this research was to evaluate the motion and time change by training aiming at shortening the slide step delivery time of baseball pitchers. Six collegiate baseball pitchers were participated in the experiment as participants. They performed three fastball pitches with full effort (both as fast and quick as possible) by slide step deliveries before (Pre) and after (Post) one-month training period. For the phase time, there were significant differences between Pre and Post in the Phase 1 and total. There were no significant differences in Phase 2 and Phase 3. The lift height of the knee of the stride leg showed no significant difference. Therefore, to shorten the time of stride phase without decrease the lift height of the knee of the stride leg is necessary to shorten the slide step delivery time

STUDIES REGARDING THE DIFFERENCE BETWEEN NORMAL SPRINTING AND RUNNING OVER FLAT MARKERS

The purpose of this study was to clarify the difference between normal sprinting (NS) and running over flat markers (FMR). Eleven male collegiate sprinters participated in this study as subjects. The subjects initially ran 50m normally, then over some markers set up on the runway, and finally they ran 50m normally again. The leg motion of the three runs were compared by two-dimensional motion analysis. FMR showed a significant increase in stride frequency, but leg motion showed no significant differences. However, there were subjects whose leg motion showed smaller hip and knee angle and angular velocity during contact phase. The results suggested that the second sprint was influenced by FMR. FMR may be a good tool for sprinting improvement to obtain a higher stride frequency

CHANGE OF MOVEMENT IN THE PELVIS DUE TO FATIGUE IN LONG-DISTANCE RUNNING- A CASE STUDY

The purpose of this study was to clarify the three-dimensional movement of the pelvis due to fatigue in long-distance running. Four collegiate long-distance runners participated in this study as subjects and ran 4000m with a 5000m race pace. Subject D, whose running pace was significantly slowest, showed a significant decrease in stride length, stride frequency, and pelvis rotation angle at the end of the 4000m run. Furthermore, Subject D showed a significant increase in pelvis elevation. These factors suggested that to maintain the range of motion of pelvis rotation and to keep the pelvis elevation movement minimal is a very important factor in maintaining running speed and attaining high performance in long-distance running

RESEARCH ON GENDER DIFFERENCES OF PREPARATIVE MOTION FOR TAKEOFF IN THE LONG JUMP

The purposes of this study were to compare the preparative motion between female and male long-jumpers whose records were approximately the same, and to obtain the characteristics of motion of female long-jumpers. The motion was the female athletes have a larger extension angles and angular velocities of the hip and knee joint in the preparative phase than the male athletes. This motion influences on a CG drop Midl is the most important role for the preparation for takeoff. Upper body motion of female athletes indicated a large tilting range of motion at the time of each foot touching down. In addition, these two motions led the deceleration of the approach velocity. Therefore, it is thought that to improve these two motions resulting in better results

KINEMATIC COMPARISONS OF DIFFERENT PITCH VELOCITY GROUPS IN BASEBALL USING MOTION MODEL METHOD

The purpose of this study was to compare kinematic parameters of the pitching motion between different pitch velocity groups. Twenty - two varsity baseball players (19 pitchers and 3 fielders) volunteered to participate in this study as subjects. Throwing motions were videotaped with two high- peed (250 fps) VTR cameras. A 15 body segment model of the pitcher was constructed from 26 body segment endpoints reconstructed with the DLT technique. The motion model was constructed for each group to compare the kinematic parameters. High-pitch velocity group had a sequence of appropriate sequence of the joint and segment movement, i.e., hip rotation, shoulder rotation, shoulder horizontal adduction, and elbow extension, while low-pitch velocity group had done the shoulder rotation and elbow extension simultaneously

TRAINING EFFECT OF RUNNING OVER FLAT MARKERS TO INCREASE STRIDE LENGTH - A CASE STUDY -

The purpose of this study was to verify the effect of running over flat markers (FMR) using longer than usual stride length intervals. One male collegiate sprinter participated in this study as the subject. The subject initially ran 100m normally, and we calculated the stride length during this run. He was FMR training for 4 weeks with a mark interval set up at 105% of usual stride length. The sprint motion of the three runs were compared by two-dimensional motion analysis. The result of the present study showed FMR changed leg motion just before the contact phase. The subject, whose leg motion showed hip angular velocity increased just before the contact phase. The result of the present study show FMR may be a good tool for sprinting improvement to change leg motion

CLASSIFICATION OF FOUR DELIVERY STYLES OF PITCHING MOTON IN YOUNG BASEBALL PLAYERS

The purpose of this study was to examine the release positions of the throwing arm and of the trunk in four delivery styles (overarm, three-quarter arm, sidearm and underarm) of the baseball pitching motion, and to identify criteria to define the four delivery styles based upon the positions of both the trunk and throwing arm (upper arm) segments. Thirty-four pitching motions were videotaped using the 3D DLT method. These motions were qualitatively classified by coaches’ observation into 15 overarm, 7 three-quarter arm, 7 sidearm and 5 underarm deliveries. The angles for the trunk lateral tilt and upper arm elevation in the global coordinate system were quantified, and regression analysis revealed a linear relationship between the two angles. Criteria based on these angles were developed that matched the coaches’ observations well, demonstrating that the baseball pitching motion could be quantitatively classified into the four delivery styles