KINEMATIC ANALYSIS OF THREE DIFFERENT BADMINTON BACKHAND OVERHEAD STROKES

The purpose of this study was to analyze the performance of three different backhand overhead strokes (smash, clear and drop). In this study, we are interested in analyzing the phase of preparation position to the point of making contact with the shuttle. Two Redlake high-speed video cameras operating at 250Hz were simultaneously used to obtain 3-D data. A repeated one-way ANOVA and Pearson product moment correlation were used to test the selected variables at .05 significant levels. It was concluded that increasing the shoulder angle of drop and the wrist angular velocity of smash and clear will increase the shuttle velocity

BIOMECHANICAL ANALYSIS OF THE UPPER EXTREMITY IN THREE DIFFERENT BADMINTON OVERHEAD STROKES

The purpose of this study is going to analyze the biomechanical variables (net joint forces, moments and powers) on the upper extremities of the international elite badminton player when he was performing different (smash, clear and drop) overhead stroke movements. In this study, we are interested in analyzing from the phase of the period before and after the point of making contact with the shuttle. The 2D inverse dynamical solution was the method to calculate the net force, net moment and the power of the upper extremity around the contact. The results showed that dynamical pattern of the three overhead strokes were different. The player experienced eccentric contraction before or after the contact. The regular training on the wrist extensors will be necessary for reduce the risk of the injury of wrist extensors

THE BIOMECHANICAL ANALYSIS OF THE TAEKWONDO FRONT-LEG AXE-KICK

The purpose of the study was to analyze the biomechanics of taekwondo front-leg axekick. One force plates, two synchronized high-speed cameras were used to measure biomechanical parameters in each phase of the front-leg axe-kick. The results included: 1. The average reaction time and movement time were 0.423 sand 0.327 s, which respectively occupied about 56% and 44% of attack time. 2. The maximum velocity of hip, knee and ankle were 1.74 m/s, 5.25 m/s and 7.43 m/s respectively. When the kicking leg touched the target, the velocity of knee and ankle were 0.78m/s, 1.72m1s, and 4.64m1s respectively. 3. The peak vertical GRF and impulse were 0.96 SW and 77.57N-s. For decreasing the movement time, it's suggested that an athlete should increase the power and flexibility of lower extremities during the training section

BIOMECHANICAL ANALYSIS OF BADMINTON DIFFERENT FORWARD STEPS

The purpose of this study was to compare the biomechanical variables between 2-step and 3-step forward steps in badminton. Eight collegiate elite male badminton players participated in this study. Eight Vicon T-20 cameras (300 Hz) were used to record the 3D kinematics data and a Kistler force plate (1500 Hz) was used to collect the GRF data of the last steps. A Wilcoxon matched-pairs signed-rank nonparametric statistical test was conducted to compare the differences between two kinds of forward step movements. The results showed that the movement time for 3-step movement was significantly faster than 2-step. We recommend that the badminton players should practice 3-step forward footwork technique. The additional strength and power training for lower limbs should be carried out for the footwork training

THE SURFACE EMG ACTIVITY ANALYSIS BETWEEN BADMINTON SMASH AND JUMP SMASH

Badminton smash is one of the most powerful techniques among all the racket sports. It may divide into smash and jump smash. The purpose of this study was to analyze the surface EMG activity of upper extremities between smash and jump smash by eight Taiwan elite badminton players. We used two digital video cameras to obtain the 3D kinematics data of shuttlecock, and measured the surface EMG signals of seven upper limb muscles. The results showed that there was no significant difference between the two smashes in initial shuttle velocity. Though the movements of the two smashes were similar, there were significant difference between the two smashes in the sequence of the surface EMG activity of the upper limb and the mean IEMG amplitude in a few muscles. We found that the jump smash exerted the higher EMG activity than smash in the phase before contact point

The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion

BACKGROUND: The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns. METHODS: Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s. RESULTS: The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects. CONCLUSIONS: The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration

THE SURFACE EMG ACTIVITY OF THE UPPER LIMB MUSCLES OF BADMINTON FOREHAND AND BACKHAND SMASHES

The purpose of this study was to analyze the surface EMG activity of the upper limb muscles of Taiwan elite badminton players when they were performing the forehand and the backhand smashes. We used two digital video cameras to obtain the 3D kinematics data of the shuttlecock, and measured the surface EMG signals of seven upper limb muscles. The results showed that there were significant differences between forehand and backhand smashes in the following variables: the initial shuttle velocity, the contact height, the initial flight angle of the shuttle, the sequence of the surface EMG activities of the upper limbs and the mean IEMG amplitude in the selected muscles. The reason why the forehand smash was faster than the backhand smash might be because the up swing displacement and up swing racket velocity of the forehand smash was greater than that of the backhand smash

Lactobacillus plantarum MYL26 induces endotoxin tolerance phenotype in Caco-2 cells

Background: Crohn's disease and ulcerative colitis are the major types of chronic inflammatory bowel diseaseoccurring in the colon and small intestine. A growing body of research has proposed that probiotics are able toattenuate the inflammatory symptoms of these diseases in vitro and in vivo. However, the mechanism of probioticactions remains unclear.Results: Our results suggested Lactobacillus plantarum MYL26 inhibited inflammation in Caco-2 cells throughregulation of gene expressions of TOLLIP, SOCS1, SOCS3, and IκBα, rather than SHIP-1 and IRAK-3.Conclusions: We proposed that live/ heat-killed Lactobacillus plantarum MYL26 and bacterial cell wall extracttreatments impaired TLR4-NFκb signal transduction through Tollip, SOCS-1 and SOCS-3 activation, thus inducing LPStolerance. Our findings suggest that either heat-killed probiotics or probiotic cell wall extracts are able to attenuateinflammation through pathways similar to that of live bacteria

THE DYNAMICAL ANALYSIS OF TABLE TENNIS FOREHAND AND BACKHAND DRIVES

The purpose of this study was to analyze the dynamics parameters of table tennis drives by Taiwan collegiate first class table tennis players when they were performing straight and cross court forehand and backhand drives from receiving topspin and backspin serves. Ten Vicon MX-13+ high-speed cameras (250Hz) and two Kistler force plates (1500 Hz) were used to collect the kinematics and kinetics data. The Wilcoxon matched-pairs signed-rank nonparametric statistical test was to compare the differences between forehand and backhand drives. The results showed that there were significant differences between forehand and backhand drives were in the ball initial velocity and the kinetics variables. The GRF data of the players were different between forehand and backhand drives when they performed four different paths of drive