Mechanism for control of ball spin rate by the upper limb in baseball pitching based on singular value decomposition.

This study aims to examine the mechanism by which the ball spin rate during fastball pitching is controlled by synergistic joint torque. The participants were seven baseball players. The kinematics and kinetics of the fingers, wrist, elbow, and shoulder were calculated using the inverse dynamics method. The synergistic relationship between the joint torques was calculated using singular value decomposition. The similarity of the spatial pattern of the joint torque in each participant was evaluated using cosine similarity. The results indicated that there were three types of synergistic torque control: (1) two pitchers had a synergistic torque control that was primarily based on shoulder internal rotation torque, (2) two pitchers had a synergistic torque control that was primarily based on elbow extension torque, and (3) three pitchers had a synergistic torque control that was primarily based on shoulder horizontal adduction torque. In particular, pitchers with a high spin rate relative to the ball velocity (SPV) had a torque control of the shoulder internal rotation type. In contrast, pitchers with a low SPV had a torque control of the shoulder horizontal adduction type. It is considered that pitchers with a high SPV execute shoulder internal rotation torque, which has the same direction as that of ball spin, based on hierarchical control to increase the ball spin rate. These results suggest that pitchers with high and low SPVs exhibit different motor patterns. Pitchers and coach need to focus on the shoulder joint as well as the fingers when they throw fastball.

Competencies That Japanese Collegiate Sports Coaches Require for Dual-Career Support for Student Athletes.

The purpose of this study was to clarify coaches' competencies (COM) regarding dual-career (DC) support for student athletes in Japan. The questionnaire survey was conducted at 31 universities with an online survey URL that was distributed to 300 collegiate athletic coaches. In total, there were 152 respondents (female, 19; male, 133; mean age, 43.15 ± 12.07 years; coaching experience, 12.83 ± 9.72 years). The online survey adopted a Japanese-translated version of the Dual-Career Competency Questionnaire (DCCQ), which has been translated into nine languages and is widely used in European counties. The scale consists of six factors and 33 items, each rated on a five-point scale of importance (IM) and possession (PO). The Japanese version of the DCCQ was validated through a confirmatory factor analysis, and the internal consistency of the items was confirmed by calculating the Cronbach's alpha coefficient. In addition, we examined differences between the IM and PO for DC support by t-tests and by calculating effect sizes. The validity and reliability of the Japanese version of the DCCQ were confirmed based on the goodness-of-fit index and Cronbach's alpha coefficients, respectively. Our examination of the differences between IM and PO in DC support revealed that coaches perceived the importance of DC support but did not possess the necessary COM to offer DC support. That finding was similar to those of previous European studies. In particular, the Japanese coaches who participated in our online survey recognized the importance of COM in terms of "collaboration with various stakeholders and departments" for DC support but did not feel as though they held sufficient COM in that regard. In other words, the improvement of DC support requires the development of a coaching program that fosters COM to work with various stakeholders. This key insight provides a direction and specific focus for programs to improve coaches' DC support for student athletes.

Randomized trial of granulocyte colony-stimulating factor for spinal cord injury.

Attenuation of the secondary injury of spinal cord injury (SCI) can suppress the spread of spinal cord tissue damage, possibly resulting in spinal cord sparing that can improve functional prognoses. Granulocyte colony-stimulating factor (G-CSF) is a haematological cytokine commonly used to treat neutropenia. Previous reports have shown that G-CSF promotes functional recovery in rodent models of SCI. Based on preclinical results, we conducted early phase clinical trials, showing safety/feasibility and suggestive efficacy. These lines of evidence demonstrate that G-CSF might have therapeutic benefits for acute SCI in humans. To confirm this efficacy and to obtain strong evidence for pharmaceutical approval of G-CSF therapy for SCI, we conducted a phase 3 clinical trial designed as a prospective, randomized, double-blinded and placebo-controlled comparative trial. The current trial included cervical SCI [severity of American Spinal Injury Association (ASIA) Impairment Scale (AIS) B or C] within 48 h after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group was administered 400 µg/m2/day × 5 days of G-CSF in normal saline via intravenous infusion for five consecutive days. The placebo group was similarly administered a placebo. Allocation was concealed between blinded evaluators of efficacy/safety and those for laboratory data, as G-CSF markedly increases white blood cell counts that can reveal patient treatment. Efficacy and safety were evaluated by blinded observer. Our primary end point was changes in ASIA motor scores from baseline to 3 months after drug administration. Each group includes 44 patients (88 total patients). Our protocol was approved by the Pharmaceuticals and Medical Device Agency in Japan and this trial is funded by the Center for Clinical Trials, Japan Medical Association. There was no significant difference in the primary end point between the G-CSF and the placebo control groups. In contrast, one of the secondary end points showed that the ASIA motor score 6 months (P = 0.062) and 1 year (P = 0.073) after drug administration tend to be higher in the G-CSF group compared with the placebo control group. Moreover, in patients aged over 65 years old, motor recovery 6 months after drug administration showed a strong trend towards a better recovery in the G-CSF treated group (P = 0.056) compared with the control group. The present trial failed to show a significant effect of G-CSF in primary end point although the subanalyses of the present trial suggested potential G-CSF benefits for specific population.

Study protocol for the G-SPIRIT trial: a randomised, placebo-controlled, double-blinded phase III trial of granulocyte colony-stimulating factor-mediated neuroprotection for acute spinal cord injury.

INTRODUCTION: Granulocyte colony-stimulating factor (G-CSF) is generally used for neutropaenia. Previous experimental studies revealed that G-CSF promoted neurological recovery after spinal cord injury (SCI). Next, we moved to early phase of clinical trials. In a phase I/IIa trial, no adverse events were observed. Next, we conducted a non-randomised, non-blinded, comparative trial, which suggested the efficacy of G-CSF for promoting neurological recovery. Based on those results, we are now performing a phase III trial. METHODS AND ANALYSIS: The objective of this study is to evaluate the efficacy of G-CSF for acute SCI. The study design is a prospective, multicentre, randomised, double-blinded, placebo-controlled comparative study. The current trial includes cervical SCI (severity of American Spinal Injury Association (ASIA) Impairment Scale B/C) within 48 hours after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group is administered 400 µg/m2/day×5 days of G-CSF in normal saline via intravenous infusion for 5 consecutive days. The placebo group is similarly administered a placebo. Our primary endpoint is changes in ASIA motor scores from baseline to 3 months. Each group includes 44 patients (88 total patients). ETHICS AND DISSEMINATION: The study will be conducted according to the principles of the World Medical Association Declaration of Helsinki and in accordance with the Japanese Medical Research Involving Human Subjects Act and other guidelines, regulations and Acts. Results of the clinical study will be submitted to the head of the respective clinical study site as a report after conclusion of the clinical study by the sponsor-investigator. Even if the results are not favourable despite conducting the clinical study properly, the data will be published as a paper. TRIAL REGISTRATION NUMBER: UMIN000018752.

Changes in metabolic syndrome and its components with lifestyle modification in Japanese men.

OBJECTIVE: Changes in metabolic syndrome and its components with lifestyle modification were evaluated in Japanese men. METHODS: We used data for 160 Japanese men (45.6+/-8.8 years) with a 1-year follow up. Anthropometric, blood examination and blood pressure measurements were evaluated. Metabolic syndrome was defined by using a criterion in Japan. All subjects were given instructions by well-trained medical staff on how to change their lifestyle. RESULTS: With a 1-year follow-up, anthropometric parameters, blood pressure (BP), triglyceride and HDL cholesterol were significantly improved and the prevalence of metabolic syndrome was significantly reduced. The number of subjects with abdominal obesity at baseline and at follow-up was higher (81 men) than that of subjects with other components at baseline and at follow-up. Parameters at baseline were significantly correlated with changes in parameters for one year. With lifestyle modification, the level of 163 mmHg in systolic BP (SBP), 115 mmHg in diastolic BP (DBP), 226 mg/dL in triglyceride and 33 mg/dL in HDL cholesterol at baseline was estimated to improve to the level without medications with a 1-year follow up. CONCLUSION: Lifestyle modification is useful for improving metabolic syndrome and its components. However, items of metabolic syndrome were improved, even when the abdominal circumference was greater than the normal value for Japanese men.

Finite-difference analysis of plasmon-induced forces of metal nano-clusters by the Lorentz force formulation.

We analyze light-induced forces on metal nano-spheres by using the three-dimensional finite-difference time-domain method with the Lorentz force formulation. Convergent analysis of the force on metal nano-particle clusters has been achieved by integrating the Lorentz and the Coulomb forces over the volume of the metal particles. Comparison to the Mie theory of radiation pressure on metal spheres under a plane wave illumination has verified rigorously the accuracy of the numerical method. We also analyze separate two metal spheres in close proximity and the results of the induced forces are compared to those in previous publications. The present method allows analysis of forces on various irregular structures; we apply the method to touching metal spheres, forming a simple cluster with a slight deformation at the contact point, to analyze the forces induced by the plasmonic resonance of the clusters. We show that the fundamental resonance modes, which newly appear in an infrared range when spheres are touching, exhibit strong binding forces within the clusters. Based on the numerical analyses we identify the resonance modes and evaluate quantitatively the infrared-induced forces on metal nano-sphere clusters.

Numerical prediction of minimum sub-diffraction-limit image generated by silver surface plasmon lenses.

Sub-diffraction-limit imaging by the surface plasmon polariton (SPP) induced in thin metal film lenses has been analyzed numerically. The SPP images are deteriorated by interference of plasmon fields in layered metal-dielectric structures. To obtain a clear imaging capability, the reflection and the transmission property of evanescent waves in the layered structures has been investigated by the finite-difference time-domain (FDTD) method. For verification, a full 3-dimensional analysis of large-scale layered structures demonstrated sub-wavelength images similar to those obtained in the recently reported experiments. The analysis has been extended further to a lithography of nano-scale images to predict the minimum possible size of the images resolved by the silver thin film lenses.

Reducing waist circumference by at least 3 cm is recommended for improving metabolic syndrome in obese Japanese men.

OBJECTIVE: We investigated the link between a reduction in waist circumference and metabolic syndrome. METHODS: 105 obese Japanese men were enrolled in this study with a 1-year follow-up. Anthropometric and body composition parameters, i.e. height, body weight, body fat percentage, waist circumference and hip circumference, blood pressure, triglyceride, HDL cholesterol and blood sugar, were evaluated. Metabolic syndrome was diagnosed using criteria developed in Japan. RESULTS: After a 1-year follow-up, the parameters of metabolic syndrome were significantly improved. The prevalence of metabolic syndrome was significantly reduced in subjects with at least 3 cm of waist circumference reduction (Group R). However, in subjects without such reduction (Group C), the prevalence of metabolic syndrome was similar to baseline levels. The prevalence of abdominal obesity, hypertension and dyslipidemia was also significantly reduced in Group R. In addition, there were remarkable differences of delta triglyceride (delta represents positive changes in parameters) and delta HDL cholesterol between Group R and Group C. CONCLUSION: At least 3 cm of waist circumference reduction may be beneficial for improving metabolic syndrome in obese Japanese men.

Linkage between oxygen uptake at ventilatory threshold and muscle strength in subjects with and without metabolic syndrome.

We evaluated the linkage between oxygen uptake at the ventilatory threshold (VT) and muscle strength in subjects with and without metabolic syndrome. We used data of 226 Japanese men with metabolic syndrome and 265 Japanese men without the syndrome. Metabolic syndrome has recently been defined by a new criterion in Japan. Oxygen uptake at VT and muscle strength, i.e. grip strength and leg strength were measured. Oxygen uptake at VT and muscle strength/body weight were found to be significantly lower in subjects with metabolic syndrome than in those without the syndrome. However, the differences did not reach significant levels after adjusting for leg strength/body weight or oxygen uptake at VT. A combination of aerobic exercise and resistance training might be considered for preventing and improving metabolic syndrome.

Relationship between changes in body weight and waist circumference in Japanese.

OBJECTIVES: We investigated the correlation between changes in body weight and body composition parameters. METHODS: We used the data of 2635 Japanese (40.2±12.2 years) at baseline and at 1-year follow-up from a database of 13522 subjects, which is available at the Okayama Southern Institute of Health in Okayama prefecture, Japan. Body weight, waist circumference at the umbilical level, hip circumference, and body fat percentage were used in the analyses. RESULTS: Body composition parameters were significantly reduced after 1 year. Changes in body weight significantly correlated with changes in waist circumference, changes in hip circumference, and changes in body fat percentage. A decrease in body weight of 3 kg corresponded to a 3.45 cm decrease in waist circumference in men and a 2.83 cm decrease in that in women. CONCLUSION: A decrease in body weight of 3 kg corresponded to an almost 3 cm decrease in waist circumference at the umbilical level in Japanese men and women.

Non-reciprocal transmission and Schmitt trigger operation in strongly modulated asymmetric WBGs.

We investigate numerically a non-reciprocal switching behavior in strongly modulated waveguide Bragg gratings (WBGs) having a longitudinally asymmetric stopband configuration. The minimum power predicted for a stable switching operation is found to be approximately 77 mW for a realistic waveguide structure made of prospective materials; we assume in this paper a nano-strip InGaAsP/InP waveguide having longitudinally asymmetric modulation of the waveguide width. The analysis has been performed with our in-house nonlinear finite-difference time-domain (FDTD) code adapted to parallel computing. The numerical results clearly show low-threshold Schmitt trigger operation, as well as non-reciprocal transmission property where the switching threshold for one propagation direction is lower than that for the other direction. In addition, we discuss the modulation-like instability phenomena in such nonlinear periodic devices by employing both an instantaneous Kerr nonlinearity and a more involved saturable nonlinearity model.

Relationship between visceral fat accumulation and physical fitness in Japanese women.

OBJECTIVE: To investigate the link between visceral fat (V) accumulation and physical fitness. DESIGN: Cross-sectional clinical investigation study. SUBJECTS: Twenty-eight overweight Japanese women with abdominal obesity (abdominal obesity) (body mass index, BMI>or=25, visceral fat area>or=100 cm2) aged 38-65 years (BMI 29.5+/-3.3 kg/m2) were enrolled in this study. They were compared with age and sex matched 28 normal weight subjects (BMI<25, visceral fat area<100 cm2) and 28 overweight subjects without abdominal obesity (overweight) (BMI>or=25, visceral fat area<100 cm2). MEASUREMENTS: Fat distribution was evaluated by visceral fat and subcutaneous fat (S) areas measured by computed tomography (CT) scanning at umbilical level. Anthropometric parameters, aerobic exercise level, muscle strength, flexibility and blood examination were also investigated. RESULTS: Anthropometric and body composition parameters were significantly higher in abdominal obesity subjects than those in normal weight subjects. BMI, waist circumference, waist hip ratio and visceral fat (V) area were also significantly higher than those in overweight subjects. Reduced oxygen uptake at ventilatory threshold (VT), lowering weight bearing index (WBI), and elevation of blood enzymes were noted in abdominal obesity subjects. There were significant relationships between oxygen uptake at VT and visceral fat area, and also between oxygen uptake at VT and WBI. CONCLUSION: Reduced aerobic exercise level and WBI are characteristic and visceral fat may play an important role for the etiology in Japanese women with abdominal obesity.

Daily exercise lowers blood pressure and reduces visceral adipose tissue areas in overweight Japanese men.

OBJECTIVE: To investigate the link between a reduction in blood pressure (BP) and daily exercise. DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: 43 overweight Japanese men aged 32-59 years (BMI, 29.0+/-2.3 kg/m2) at baseline. Among the participants, a randomly selected 23 overweight men (BMI, 28.5+/-1.7) were further enrolled into the 10 months exercise program. MEASUREMENTS: BP was measured every week and steps per day were also recorded every day throughout the observation period. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical level, at before, 5 months and after intervention. Anthropometric parameters were also measured at same point. Aerobic exercise level, muscle strength, flexibility and calorie intake and insulin resistance (HOMA index) were investigated at before and after the study. RESULTS: In a cross sectional analysis, systolic BP (SBP) and diastolic BP (DBP) were significantly correlated with body composition. In a second longitudinal analysis, SBP was significantly reduced at 2 months and DBP was also reduced at 3 months, and almost maintained until the end of the observation period. Increasing daily walking was observed in 3 months and maintained until 10 months. Body composition, aerobic exercise level, muscle strength, flexibility and insulin resistance were significantly improved. There was positive correlation between DeltaDBP and Deltavisceral fat area (1-5, 5-10, 1-10 months). By stepwise multiple regression analysis, only Deltavisceral fat area was independently related to DeltaDBP at a significant level (1-10 months: DeltaDBP=-0.608+0.105Deltavisceral fat area, r2=0.227, P=0.0334). CONCLUSION: The present study indicated daily exercise lowers BP and visceral fat area is the critical factor for BP change.

Evaluation of exercise prescription for hypertensive obese men by ventilatory threshold.

BACKGROUND: Prescription of aerobic exercise for obese subjects with mild hypertension in clinical practice remains to be investigated. METHODS: Forty-one Japanese obese males with hypertension were enrolled and compared with 41 age-and sex-matched obese subjects without hypertension and control subjects. In addition, 25 obese subjects with or without hypertension participated in a one-year follow up study. They were instructed to keep their low exercise intensity and record their daily walking. Before and after exercise prescription, body composition, blood pressure and aerobic exercise level were evaluated. Ventilatory threshold (VT) was determined breath by breath during exercise test using a ramp protocol and rates of oxygen consumption (VO2), work rate (WR), heart rate (HR), deltaHR, %HR max, %HR reserve and rate of perceived exertion (RPE) were measured at VT. RESULTS: At VT, obese subjects with hypertension had significantly lower VO2 (13.5 +/- 2.1 mL/kg/min) and WR (75.1 +/- 16.5W) than control subjects (VO2, 18.1 +/- 5.7; WR, 92.0 +/- 32.4). %HR reserve was also significantly lower compared with control subjects, while %HR max, was not different. RPE was also similar among the 3 groups. By prescribed low-grade exercise during one-year follow-up study, not only body composition but also blood pressure at rest was improved in obese subjects with and without hypertension. CONCLUSIONS: Our results indicated reduced exercise capacity in Japanese obese males. Exercise intensity of 60%HR max, 30%HR reserve and RPE 12 is recommended in obese subjects with hypertension as well as obese subjects without hypertension.

[Evaluation of an exercise program for obese males].

PURPOSE: We developed a one-year exercise program based on evaluation of life style and physical fitness and investigated its efficacy. SUBJECTS AND METHODS: Sixty one Japanese males (30 < or = age < 59, body mass index: BMI > or = 26.4 kg/m2) were enrolled in the stady. The exercise program consisted of four sections: (1) Preparation for preventing injury; (2) Increase of daily activity; (3) Enjoying exercise; (4) Preparation and practice of individual-based on a exercise program. The subjects visited Okayama Southern Institute of Health and were being monitored weekly for one-year. They were instructed to check daily steps every day and increase daily walking to at least 1000 steps more than the daily walk at baseline. Before and after one-year follow up study, we evaluated life style and physical fitness in terms of body composition, aerobic exercise level, muscle strength and flexibility. RESULTS: The continuation rate for the program was 66%. Body weight (pre 81.5 +/- 7.4 kg vs post 78.6 +/- 7.3 kg), body fat percentage (pre 30.3 +/- 4.1% vs post 28.4 +/- 5.0%) and waist hip ratio (pre 0.95 +/- 0.04 vs post 0.92 +/- 0.04) were significantly reduced. Aerobic exercise level and muscle strength were increased. Regarding volition for exercise, execution, continuation and steps per day were also improved. CONCLUSION: Regular exercise at an institution (once a week) and change in daily life style may play critical role in reducing body weight. This new program proved quite useful for Japanese obese males.

Daily walking reduces visceral adipose tissue areas and improves insulin resistance in Japanese obese subjects.

OBJECTIVE: It is known that the accumulation of abdominal fat is one of the risk factors for atherosclerosis. Although exercise is commonly prescribed to reduce body weight, the efficacy of low intensity exercise for the reduction of abdominal visceral adipose tissue remains to be investigated. RESEARCH DESIGN AND METHODS: Thirty one obese Japanese males (body mass index (BMI) > or = 25) ranging in age from 32 to 59, participated in a 1-year follow up study and they were instructed to have a modest increase in daily activity and record their daily walking. Before and after exercise prescription, body composition, blood pressure, physical fitness i.e. aerobic exercise level, muscle strength and flexibility were recorded. Insulin resistance was evaluated using a homeostasis model assessment, the HOMA index. RESULTS: HOMA index, parameters of body composition, blood pressure, triglyceride and HDL cholesterol were significantly improved. The aerobic exercise level, leg strength, weight-bearing index (leg strength/body weight) and the steps taken per day were significantly increased. By stepwise multiple regression analysis, Delta visceral adipose tissue area was the major determinant for Delta HOMA index. (Delta HOMA index=-0.386+0.016 Delta visceral adipose tissue area, r2=0.267, P<0.01). Exercise capacity and calorie intake were not significantly related to Delta visceral adipose tissue area, while Delta steps per day was significantly correlated with Delta visceral adipose tissue area (Delta visceral adipose tissue area=-21.363-0.004 Delta steps per day, r2=0.184, P=0.0326). CONCLUSIONS: Taken together, intra-abdominal visceral adipose tissue is critically involved in insulin resistance and daily walking rather than improvement of exercise capacity correlated with the reduction of visceral adipose tissue in obese Japanese males.

Bone status assessment in Japanese subjects using speed of sound along the tibia.

OBJECTIVES: To explore the potential use of ultrasound measurement (SoundScan 2000 Compact, Myriad Ultrasound Systems Ltd., Rehovot, Israel), and to assess both quantitative and qualitative properties of bone. METHODS: The speed of sound waves (SOS; m/s) propagating along the cortical bone was determined at the tibial shaft. The performance, reliability, validity, and clinical application of this system were evaluated in Japanese subjects. RESULTS: In phantom experiments, validity of this system was 0.04 (%), coefficient variation (CV: %) in same-day tests was 0.12, in five-separate-day tests was 0.13, and in independent operators was 0.11, respectively. In experiments with Japanese subjects, CV in same-day tests was 0.38, in five-separate-day tests was 0.99, and in independent operators was 0.90, respectively. In addition, cortical bone status of 1176 Japanese subjects (372 males, 804 females) was clinically evaluated by SoundScan 2000 Compact. SOS was negatively correlated with body fat percentage (%), body fat (kg) and waist hip ratio in females and subjects with higher weight bearing index (leg strength/body weight; WBI) have higher SOS in females under the age of forty. CONCLUSIONS: These findings indicate that the SoundScan 2000 Compact is a highly reliable and valid method for determining cortical bone status and body composition and WBI are closely related to cortical bone status in Japanese females.