KINEMATICS OF TABLE TENNIS TOPSPIN FOREHANDS: EFFECTS OF PERFORMANCE LEVEL AND BALL SPIN

INTRODUCTION: The topspin forehand in table tennis is an effective offensive shot especially against backspin balls. It would be interesting for coaches and players to compare the kinematics of the stroke between different performance level players and between different ball spins. The purpose of this study was to clarify whether performance level and ball spin affect the kinematics of the table tennis topspin forehand

UNCONTROLLED MANIFOLD ANALYSIS OF JOINT ANGLE VARIABILITY DURING TABLE TENNIS FOREHAND

The purpose of this study was to evaluate the variance structure of the trunk and racket arm joint angles in the table tennis topspin forehand in relation to the control of racket orientation using the uncontrolled manifold (UCM) approach. Seventeen (9 advanced and 8 intermediate) male collegiate table tennis players performed the strokes against backspin. The UCM analysis was conducted using 30 trial data per each participant. The degree of redundancy exploitation to stabilize the racket vertical and horizontal angles were not significantly different between the two performance levels, suggesting that the ability to exploit joint configuration redundancy may not contribute to achieving higher performance in sport hitting skill. The degree of redundancy exploitation is highest at ball impact and this result may reflect that the table tennis forehand is a fast interceptive task

EFFECT OF MECHANICAL PROPERTIES OF THE LOWER LIMB MUSCLES ON MUSCULAR EFFORT DURING TABLE TENNIS FOREHAND

The purpose of this study was to investigate the effect of the maximum isometric forces and the maximum shortening velocities of the lower limb muscles on the muscular effort during the table tennis forehand. Four male collegiate players performed table tennis forehand drives with maximum effort. We used OpenSim’s static optimization algorithm to estimate the activation patterns of lower limb muscles. The cost function was the sum of squared muscle activations for all lower limb muscles, which we will refer to as the muscular effort. The simulations were repeated with the maximum isometric forces or the maximum shortening velocities of each muscle group changed by ±10% of their original values. The results suggest that increasing the maximum isometric forces of the hip extensors and adductors may be most effective to reduce the muscular effort

MOMENTA OF BODY SEGMENTS CONVERTED INTO IMPACT FORCE OF A REAR HAND STRAIGHT PUNCH INTO AN UNFIXED TARGET

INTRODUCTION: When top-class martial artists such as champion kickboxers threw a rear hand straight punch with maximum effort into a target fixed on a wall, the contribution of the momentum of the throwing limb to an impact force or an impulse to the target was about 60% (Yoshihuku,1987). Yoshihuku (1995) suggested that the contribution of the momenta of the other body segments reduced when the punch was thrown into an unfixed target. The purpose of this paper was to clarify the contribution of the momentum of the throwing limb to the impulse when the punch was thrown into an unfixed target similar to the human head

Indistinguibilidad de la cinemática de la raqueta y del cuerpo en diferentes servicios de tenis de mesa en jugadores internaciones de élite e intermedios

Table tennis serves are strokes in which disguise and deception skills are important. This study aimed to investigate whether international elite table tennis players can make their racket and body kinematics more indistinguishable than intermediate players during three different serve types. Five former international elite and 8 intermediate players performed 3–12 trials of each serve type. The kinematics of the server’s body and the racket was determined using a motion capture system. The time instant of racket-ball impact was determined using a high-speed video camera with the motion capture system. Misclassification rates when the serve type was classified using the racket and body kinematics were determined using linear discriminant analysis. Elite players showed higher misclassification rates for the racket kinematics than intermediate players during the early swing and follow-through phases. The body kinematics suggested that the elite players made their racket kinematics more indistinguishable using different approaches between the early swing and follow-through phases. The elite players tended to make the racket’s angular velocity more similar and make the wrist rotational variables more indistinguishable in different serves compared to the intermediate players during the early swing phase. In contrast, the elite players made the racket’s linear motion more variable within individual serve types than the intermediate players during the follow-through. The results suggest that intermediate players are recommended to practice making wrist angular motions more similar during the early swing phase and making racket linear motions more variable during the follow-through in order to improve the disguise skill in table tennis serves.Los servicios en el tenis de mesa son movimientos en los que las habilidades para enmascarar y engañar son importantes. El objetivo de este estudio fue investigar si los jugadores de tenis de mesa de élite internacionales pueden hacer que la cinemática de su raqueta y cuerpo sea más indistinguible que los jugadores intermedios durante tres tipos de servicio diferentes. Cinco exjugadores internacionales de élite y 8 jugadores intermedios realizaron de 3 a 12 intentos de cada tipo de servicio. La cinemática del cuerpo y de la raqueta del servidor fue determinada a través de un sistema de captura del movimiento. El momento del impacto raqueta-pelota fue determinado usando una videocámara de alta velocidad con sistema de captura de movimiento. Las tasas de clasificación errónea cuando el tipo de servicio fue clasificado usando la cinemática de la raqueta y del cuerpo fueron determinadas por medio de un análisis discriminante linear. Los jugadores de élite mostraron tasas de clasificación errónea más altas en la cinemática de la raqueta que los jugadores intermedios durante la fase inicial del swing y la fase de terminación. La cinemática del cuerpo sugirió que los jugadores de élite hicieron su cinemática de la raqueta más indistinguible al usar diferentes enfoques entre la fase inicial del swing y la de terminación. Los jugadores de élite tuvieron una tendencia a hacer que la velocidad angular de la raqueta fuera más similar y las variables de rotación de la muñeca fueran más indistinguibles en diferentes servicios comparados con los jugadores intermedios durante la fase inicial del swing. En contraste, los jugadores de élite hicieron que el movimiento lineal de la raqueta fuera más variable en tipos de servicio individual que los jugadores intermedios durante la terminación. Los resultados sugieren que los jugadores intermedios deberían hacer movimientos angulares de muñeca más similares durante la fase inicial del swing y hacer que los movimientos lineares de la raqueta sean más variables durante la terminación para mejorar la habilidad para enmascarar los servicios de tenis de mesa

Improvement of the human intestinal flora by ingestion of the probiotic strain Lactobacillus johnsoniiLa1

To exert beneficial effects for the host, for example, improving the intestinal microflora, a probiotic must reach the intestine as a viable strain. These properties must be demonstrated by in vitro as well as in vivo methods. However, only a few well-designed human clinical studies have shown these properties. Lactobacillus johnsonii La1 has been shown to give many beneficial effects for the host, but it is unclear whether a viable strain of L. johnsonii La1 has the effect of improving host intestinal microflora. In the present study, a randomised double-blind placebo-controlled cross-over trial was conducted to elucidate the effect of L. johnsonii La1 on human intestinal microflora. Twenty-two young healthy Japanese women were randomly divided into two groups, and either received fermented milk with L. johnsonii La1 or a fermented milk without L. johnsonii La1 (placebo) daily for 21d. Consumption of the fermented milk: (a) increased total Bifidobacterium and Lactobacillus, and decreased lecithinase-positive Clostridium in the faeces; (b) increased the faecal lactic acid concentrations; (c) decreased the faecal pH; (d) increased the defecation frequency. These changes were stronger than those observed with the placebo. L. johnsonii La1 was identified in all subjects only after the consumption of the fermented milk. These results suggest that L. johnsonii La1 can contribute to improve intestinal microflora with probiotic propertie

Improvement of nutritional status and incidence of infection in hospitalised, enterally fed elderly by feeding of fermented milk containing probiotic Lactobacillus johnsonii La1 (NCC533)

Probiotics have potential to improve host immunity; however, there is less evidence showing their efficacy against infections and nutritional status in the elderly. We conducted a double-blinded feeding trial in the elderly to elucidate the effect of fermented milk containing Lactobacillus johnsonii La1 (LC1®) on infections and nutritional status. Twenty-four completely enterally fed elderly in-patients aged over 70 years were randomly assigned into two groups. All subjects were administered 3768kJ (900kcal)/d of total enteral nutrition (EN) through tube feeding for 12 weeks. Subjects in the LC1 group were administered 373kJ (89kcal)/d of LC1 fermented milk after feeding of 3395kJ (811kcal)/d of EN for 12 weeks. In the control group, 373kJ/d of the same EN was replaced from the fermented milk. In the LC1 group, the percentage of days with infections during the run-in observation period was 15·4 (sd 17·3) %, which significantly decreased to 5·7 (sd 8·1) % during the intervention period (P=0·018), and the reduction was larger than that of the control group (P=0·047). Blood Hb increased (P<0·05), and there was a tendency towards an increase in serum albumin and a decrease in TNF-α (a pro-inflammatory cytokine) in the LC1 group. There was a trend towards an increase in blood phagocytic activity (a natural immunity marker) in the subjects whose initial level was low in the LC1 group. There were no changes in those parameters in the control group. Administration of fermented milk containing the probiotic L. johnsonii La1 may contribute to suppressing infections by improving nutritional and immunological status in the elderl

Effects of mild calorie restriction and high-intensity interval walking in middle-aged and older overweight Japanese

We investigated whether a combination of mild calorie restriction (MCR) and high-intensity interval walking (HIW) improved physical fitness more than HIW alone in middle-aged and older overweight Japanese (40-69 years old, BMI >= 23.6 kg/m(2)). Forty-seven women and 16 men were divided into MCR + HIW and HIW groups. All subjects performed HIW: >= 5 sets of 3-min low-intensity walking (40% peak aerobic capacity for walking, VO2peak) and 3-min high-intensity walking (>= 70% VO2peak) per day, >= 4 days per week, for 16 weeks while energy expenditure was monitored with a tri-axial accelerometer. The MCR + HIW group consumed meal replacement formula (240 kcal): a mixture of low-carbohydrates and -fat and high-protein, for either lunch or dinner everyday and therefore, had similar to 87% of the energy intake of the HIW group during the intervention period. Although the HIW group showed improvements in BMI, blood pressure, and several blood chemicals, the MCR + HIW group had greater improvement. Moreover, the medical expenditure for the 6 months including the intervention period was 59% lower in the MCR + HIW group than in the HIW group. Our strategy of a short-term combination of MCR and HIW may thus prevent lifestyle-associated diseases and improve health in middle-aged and older overweight Japanese.ArticleEXPERIMENTAL GERONTOLOGY. 44(10):666-675 (2009)journal articl

Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection

Protocol for a multicentre, prospective observational study of elective neck dissection for clinically node-negative oral tongue squamous cell carcinoma (END-TC study)

Introduction: In early-stage oral tongue squamous cell carcinoma (OTSCC), elective neck dissection (END) is recommended when occult lymph node metastasis is suspected; however, there is no unanimous consensus on the risks and benefits of END in such cases. The management of clinically node-negative (cN0) OTSCC remains controversial. This study, therefore, aimed to evaluate the efficacy of END and its impact on the quality of life (QoL) of patients with cN0 OTSCC. Methods and analysis: This is a prospective, multicentre, nonrandomised observational study. The choice of whether to perform END at the same time as resection of the primary tumour is based on institutional policy and patient preference. The primary endpoint of this study is 3-year overall survival. The secondary endpoint are 3-year disease-specific survival, 3-year relapse-free survival and the impact on patient QoL. Propensity score-matching analysis will be performed to reduce selection bias. Ethics and dissemination: This study was approved by the Clinical Research Review Board of the Nagasaki University. The protocol of this study was registered at the University Hospital Medical Information Network Clinical Trials Registry. The datasets generated during the current study will be available from the corresponding author on reasonable request. The results will be disseminated internationally, through scientific and professional conferences and in peer-reviewed medical journals