SIMULATION SYSTEM FOR IMPROVING TENNIS STROKE MOTION

The purpose of this study was to construct a system that can simulate tennis stroke motion for competition level enhancement of players. To do so, 10 female tennis club players (1 9- 23 years old) of University of Tsukuba were selected for a biomechanics study using three-dimensional stroke motion analysis method, in a total of 10 trials. Using obtained results on joint angles of the whole body, the best results of university tournament and racket head speed at impact, a database was constructed. Principal component analysis was used to classify the motion patterns into the principal component scores. Based on the principal component score and optimization theory, we generated a simulation system to predict competition level and racket head speed, and thus a new stroke motion, which can be expressed using 30 animations

A SIMPLE METHOD TO MEASURE EXTERNAL FORCE, POWER OUTPUT AND EFFECTIVENESS OF FORCE APPLICATION DURING SPRINT ACCELERATION

The aim of this applied session was to introduce and show a recently validated simple field method to determine individual force, velocity, power output properties and effectiveness of force application onto the ground during a sprint running acceleration. This method requires the use of a radar device (or several timing gates), and models the horizontal, vertical and resultant force an athlete develops over sprint acceleration using a macroscopic inverse dynamic approach. Low differences in comparison to force plate data support the validity of this simple method to determine force-velocity relationship and maximal power output, as well as the index of effectiveness of force application onto the ground. Its validity and ease of use make it an interesting tool for sprint training and performance optimization, in a specific field context of practice

SPECIFIC AND NON SPECIFIC ROWING FIELD EVALUATION CORRELATED WITH ERGOMETER ROWING PERFORMANCE

This study aimed at testing the possible correlation between rowers’ ability to generate power during a rowing Wingate test or a squat jump test and a rowing ergometer performance. Mean power developped during the Wingate test (PWIN), force, velocity and power output in squat jump (FSJ, VSJ and PSJ) and mean power (P1500) sustained during an all-out 1500-m sprint ergometer were measured in fourteen young rowers (15.3±0.6 yr, 178.5±8.8 cm, 67.9±10.8 kg). PWIN was significantly correlated to P1500 (r=0.90,

THE EFFECTS OF TWO DIFFERENT TYPES OF DYNAMIC WARM-UP AND STATIC STRETCHING ON POWER AND SPEED

Static stretching has often been found to decrease performance in power and speed activities, but dynamic warm-ups usually increase performance. We examined the effects of a mini-band warm-up, a medicine ball warm-up, and static stretching on 10m and 20m sprint times, as well as overhead medicine ball throw performance. Twenty-four Division I female soccer players completed the three warm-ups and a control 5 minute jog condition on separate days and were tested on the 10m and 20m sprint times and overhead medicine ball throw. ANOVA\u27s and follow-up paired t-tests ( ~ ~ 0 . 0 5w)er e used to determine differences between the warm-ups. Significant differences were found between groups for the 1 Om sprint times but not for the 20m sprint times or the overhead medicine ball throw

A KINEMATICS ANALYSIS OF GIANT SWING BACKWARD AND DOUBLE SALTO BACKWARD STRETCHED DISMOUNT IN JINNAN YAO ’S UNEVEN BARS

Using 3D camera analytic method, the paper tests Jinnan Yao’s (who won the gold medal in the female uneven bars final of the 45th World Gymnastics Championship in October 11th ,2014) technical movements of giant swing backward and double salto backward stretched dismount and make a kinematics analysis of the complete movements.The purpose of this study was to reveal the kinematic rules and technical features of the movements, in order to provide references of technical training for athletes. The results indicated that better performance was demonstrated if gymnast could increase the height of salto suspension,so that increase the flight time ,in order to prepare landing

CLIMBER’S HAND INJURIES

Rock climbing is a sport activity which solicited the fingers more than other any sport, leading to injuries typical for the rock climbers\u27 hand. The biomechanical functioning of the finger is one of the most complicated problems of the human musculo-skeletal system. This paper describes the pathologies observed in rock climbing and the knowledge obtained thanks to biomechanical analysis for the evaluation and simulation for treatment and repair

KINEMATIC COMPARISONS BETWEEN FORWARD AND BACKWARD SKATING IN ICE HOCKEY

The purpose of this study was to examine the kinematics of lower body and trunk between forward and backward skating. Seven male collegiate ice hockey players skated both forward and backward (C-cut) four times each. A standard two-dimensional kinematic analysis was conducted to examine the lower body extremity and trunk at the instants of weight acceptance and propulsion. No significant differences in the joint angles were found at the weight acceptance. At the propulsion, significant differences were found in the joint angles of hip, knee, ankle and trunk between forward and backward skating. Hence, these findings indicate the importance of strengthing lower body joints and trunk, particularly for forward skating. Future studies are warranted to examine the mechanics of forward and backward skating using a 3D analysis

THE EFFECTS OF QUADRICEPS TAPING AND NOWTAPING APPROCHES ON COUNTERMOVEMENT JUMP PERFORMANCE

Kinesio is one of the most common adhesive therapeutic tapes. Expect for clinical applications, kinesio claims to be able to enhance muscle activity performance. The purpose of this study was to investigate the effect of kinesio taping on quadriceps during a maximal counter-movement jump. Six healthy men was recruited in this study (Height: 173.8 k 4.2 em; Weight: 68.8 k 7.3 kg; Age: 22.9 k 2.3 yrs ). The kistler force plate was used to measure the jump height, takeoff force and landing force. No significant differences between two groups. The results showed that kinesio tape did not affect muscle activity and ground recreation force, jumping height and landing force

EFFECT OF ARCH SUPPORT FOOT ORTHOSIS ON LOWER WTREMIN LOADING AND KINEMATICS DURING THE REBOUND

The purpose of this study was to determine whether arch support foot orthosis was capable of altering lower extremity loading and kinematics during the rebound. Nineteen female Division I basketball players participated in this study. Utilizing a repeated measures design, participants completed two rebound tasks with and without the arch support foot orthosis. Results showed that the selected arch support foot orthosis significantly decreased the peak impact force, knee internal rotation and foot inversion angle at the initial contact of the ground compared to those of the flat insole. It suggested that the use of the arch support foot orthosis can decrease the lower extremity loading and further decrease the risk of ACL injury in female basketball players

EFFECT OF DIFFERENT TIBIA ANGLES TO LOADING OF KNEE DURING SPLIT SQUAT

The aim of this study was to investigate the difference of knee joint force and moment during split squats of different front tibia angles. Twelve healthy male college students performed six repetitions of four different split squat types with a standard additional load of 25% BW added using a barbell. Using 10 camera 3D motion capture system and a force plate to collect data. The peak force and moment of knee flexion (sagittal plane) were calculated by using self-designed MATLAB programs. One-way ANOVA test was undertaken using SPSS 20.0 statistical software. The analysis results of the study indicated that all kinetic parameters of the four types split squats were achieved high significant differences (p less than .000). A better understanding of different loading in specific joints and correct exercise execution during training will help protecting practitioners from sport injury