Publications (9)6.38 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: We examined changes in neutrophil function of soccer players over a 10-month period and determined its effectiveness as an index for athlete physical condition. Subjects included 21 male professional Japanese soccer players. Data on body composition, myogenic enzymes and neutrophil function were obtained before and after 2 h of training at 3 investigation points: one week before opening season, at season mid-point, and one week before the last game of the season. As a result, change ratios of myogenic enzyme levels before and after the 2-hr training session at the third investigation point were significantly higher compared to the two other points. Reactive oxygen species production and phagocytic activity significantly increased after 2-hr training session at point 1, although the extent of the increase became smaller over time and ROS production capability decreased significantly by point 3 assessment. Fatigue, especially muscle fatigue, chronically accumulated along with a gradual decrease in neutrophil immune function over the 10-month season. Therefore, determination of neutrophil function can be used as a useful index to assess and understand an athlete's physical condition. Copyright © 2012 John Wiley & Sons, Ltd.
- [Show abstract] [Hide abstract] ABSTRACT: This paper presents a wireless inertial measurement system to analyze three- dimensional (3D) pitching movement of baseball. Developed wireless inertial measurement unit (WIMU) sizes 43.7×45.2×25.7 [mm], weighs 48 [g] including Lithium-Ion battery, and consists of two types of 3D accelerometers, two types of 3D gyroscopes, release sensor, a microcontroller (MCU), flash memory, and an RF module. Synchronization of start and completion of measurement procedure for plural WIMUs are wirelessly controlled by a host computer. Three-dimensional pitching form of upper limb and trunk is produced by the numerical integration of the acceleration and angular velocity. The experimental results show that 3D posture, trajectory and joint torque in overhand and sidearm throwing are successfully estimated using the proposed system.
- [Show abstract] [Hide abstract] ABSTRACT: The aim of this study is to propose the measurement method of three-dimensional (3D) movement of forearm and upper arm during pitching motion of baseball using inertial sensors without serious consideration of sensor installation. Although high accuracy measurement of sports motion is achieved by using optical motion capture system at present, it has some disadvantages such as the calibration of cameras and limitation of measurement place. Whereas the proposed method for D measurement of pitching motion using body mounted sensors provides trajectory and orientation of upper arm by the integration of acceleration and angular velocity measured on upper limb. The trajectory of forearm is derived so that the elbow joint axis of forearm corresponds to that of upper arm. Spatial relation between upper limb and sensor system is obtained by performing predetermined movements of upper limb and utilizing angular velocity and gravitational acceleration. The integration error is modified so that the estimated final position, velocity and posture of upper limb agree with the actual ones. The experimental results of the measurement of pitching motion show that trajectories of shoulder, elbow and wrist estimated by the proposed method are highly correlated to those from the motion capture system within the estimation error of about 10 [%].
- [Show abstract] [Hide abstract] ABSTRACT: This paper describes a measurement method of three-dimensional (3D) forearm movement during pitching motion using an elbow-mounted sensor (3D sensor). The 3D sensor comprises accelerometers of two kinds with dynamic range of 4 [G] and 100 [G], and two kinds of gyroscopes with dynamic range of 300 [deg/s] and 4000 [deg/s], respectively, because the sensors used in measurement of sports activities require a wide dynamic range. The 3D sensor, attached on the forearm, measures 3D acceleration and angular velocity. The 3D trajectory of the forearm is estimated through double integration of the measured acceleration, which is transformed from the acceleration based on the system of moving coordinate on the forearm to that on the fixed system of coordinates. Because the estimated trajectory of the forearm is affected by the numerical integration of the measured data including errors, the 3D trajectory error is reduced by determining the position and posture of the forearm at the end of the pitching motion. Results of the pitching experiment show that the 3D trajectory and angle of the forearm estimated by the 3D sensor agree with those measured from a video camera image with an error margin of around 10 %.
- [Show abstract] [Hide abstract] ABSTRACT: In order to examine in detail the influence on the neutrophil immune function in sumo wrestlers of performing traditional and original training we examined changes in the neutrophil immune function in 17 male amateur university sumo wrestlers (aged 20.2 +/- 1.5 years), before ('Pre') and after the training ('Post') for 2.5 h under fasting conditions. Assays included blood leukocyte and neutrophil counts, serum concentration of immunoglobulins, complements, myogenic enzymes and neutrophil oxidative burst activity (OBA) and phagocytic activity (PA). Myogenic enzymes, neutrophil counts, the ratio of neutrophil counts:leukocyte counts significantly increased and immunoglobulins and complements decreased in Post compared with Pre. There was a positive correlation between the change of neutrophil counts before and after the training and the change of creatine kinase (r = 0.667, p < 0.01). The Post OBA significantly increased and PA significantly decreased compared with Pre. It was concluded that sumo training causes muscular damage and an increase in the neutrophil count as a response. In this time, although OBA increased, PA decreased after training. Compensation between PA and reactive oxygen species production may exist to maintain the overall integrity of the neutrophil immune function.
- [Show abstract] [Hide abstract] ABSTRACT: Diagnosis method of anterior cruciate ligament (ACL) using body-mounted sensor is discussed. A wide variety of diagnosis method such as Pivot Shift Test (PST), Lachman Test and monitoring of jump motion (JT) are applied to examine the injured ACL. These methods, however, depend on the ability and the experience of examiner. The proposed method numerically provides three dimensional translation and rotation of the knee by using a newly developed 3D sensor. The 3D sensor is composed of three accelerometers and three gyroscopes. Measured acceleration of the knee during the examination is converted to the fixed system of coordinate according the acceleration of gravity and 3D rotation of the sensor, and is numerically integrated to derive 3D trajectory and rotation angle around the tibia. The experimental results of JT suggest that unsymmetrical movement of rotation angle of the tibia and sudden movement of estimated 3D trajectory show instability of knee joint. From the results of PST analysis, it is observed that the tibial angular velocity around the flexed position changes 41.6 [deg/s] at the injured side and 21.7 [deg/s] at the intact side. This result suggests the reposition of injured knee from subluxation.
- [Show abstract] [Hide abstract] ABSTRACT: To evaluate the dietary fiber (DF) intake pattern among the Japanese general population. We performed a dietary survey among the general population in northern Japan to evaluate the intake patterns. DF intake was calculated by substituting the DF content of each food in the Dietary Fiber Table for the intake of each food from this dietary survey. Five hundred and seventy-seven subjects participated in the study, 198 men and 379 women. In subjects with higher DF intakes the origins of the DF that were from all food groups, but with the notable exception of rice. The contribution of the seaweed group was of particular interest. From multiple regression analysis, as for food group, seaweeds showed the highest positive correlation with DF intake in both genders, followed by vegetables, pulses, fruits. On the other hand, rice showed the negative correlation with DF intake in both genders. As for life factor, body mass index showed the negative correlation with DF intake in women. Seaweed, a typical Japanese food, was most related to the increase in DF intake for the Japanese general population, whereas rice, the Japanese staple, had a small influence on decreased DF intake.
- [Show abstract] [Hide abstract] ABSTRACT: Sumo wrestling is a very powerful and competitive contact sport played by extremely fit and highly trained competitors. Due to the extremely competitive nature of the sport and the required training, injuries are common both during training and the actual competition. Long-term lay-up of the competitor has to be avoided in order to maintain the level of muscle tone and mental concentration generated by the grueling training, so postinjury recovery time is kept to a minimum. A noninvasive therapy is therefore required, and the recent interest in the successful application of low level laser therapy (LLLT) in pain attenuation for a large number of pain types suggested that it might offer a new tool for sumo-related injuries. The current trial, with ten sports university sumo wrestlers, examined the effect of LLLT on injuries of the knee (five subjects) and foot (five subjects), using laser speckle flowmetry to assess the possible increase in superficial blood flow which has been associated with both pain attenuation and accelerated wound healing. An 830 nm 60 mW GaAlAs diode LLLT system was applied on one point for 5 min (approximately 15 J/cm2), and laser speckle flowmetry was performed before, during, immediately after, at 30 min and 60 min after irradiation. Decreased blood flow was seen intrairradiation, but an increase, significant in 7 of the 10 subjects was seen immediately postirradiation. This was maintained at significantly elevated levels in 4 subjects, while the remaining six decreased slightly, but in all ten subjects elevated levels of superficial blood flow were seen at one hour postirradiation, compared with preirradiation. LLLT is noninvasive, easy to apply, well tolerated and adverse side effect free. It is suggested that, following further trials to elucidate dosimetry and possible wavelength specificity, LLLT may well offer an exciting new tool to the sports clinician treating injured sumo wrestlers.
Khirosaki, Aomori, Japan
- Department of Science Radiological Technology