シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集
Online ISSN : 2432-9509
2015
選択された号の論文の114件中1~50を表示しています
  • 原稿種別: 目次
    p. 1-6
    発行日: 2015/10/30
    公開日: 2017/06/19
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  • 三宅 悠斗, 菅 唯志, 大塚 光雄, 田中 貴大, 御前 純, 工藤 将馬, 長野 明紀, 伊坂 忠夫
    原稿種別: 本文
    セッションID: A-1
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Although plantar flexor torque increases the sprint velocity by enhancing the ground reaction force, it is yet unkown whether the proportions of the triceps surae muscle and ankle joint, both of which are related to the production of plantar flexor torque, affect sprint performance. Therefore, in the present study, we examined the relationship of the triceps surae muscle with ankle joint proportions and performance in sprinters. Thirty-two well-trained sprinters participated in this study. The proportions of the triceps surae muscle and ankle joint were measured by using magnetic resonance imaging. In the proportions of the triceps surae muscle, the muscle volume of the gastrocnemius medialis (GM), not the gastrocnemius lateralis and soleus, was significantly correlated with the sprinter's personal best time in a 100-m race (R=-0.391, P=0.032). Moreover, location of the muscle-tendon junction of the GM was also significantly correlated with the 100-m performance (R=0.445, P=0.014). In contrast, the ankle moment arm length, a proportion of ankle joint, was not significantly correlated with the 100-m performance; however, only a trend was noted (R=-0.317, P=0.088). The present findings suggest that a larger muscle volume and a lower location of the muscle-tendon junction of the GM in the triceps surae muscle may help achieve a successful sprint performance, potentially by producing a larger plantar flexor torque.
  • 小野寺 勇哉, 高橋 亜佑美, 見坐地 一人
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    セッションID: A-2
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The main reason of reduction walking ability is muscle weakness of the psoas major. But muscular strength of the psoas major judged from cross sectional area in the previous researches. In this paper, we analyzed quantitatively muscles around the hip joint for extension and flexion movement of knee joint by using angular momentum. We think that angular momentum expresses the intensity of muscle exercise. First, we used the 3D lower limbs musculoskeletal model of SCOT L. DELP. And, we estimated muscle activation of muscles around hip joint by using the 3D loer limbs musculoskeletal model. 3D lower limbs musculoskeletal model used Hill type model which F.E.Zajac suggested. Next, the muscle torque was calculated from muscle activation of muscles around the hip joint. Finally, the angular momentum was calculated from the muscle torque around the hip joint. And, the driving power was calcuated from driving torque of the hip joint. As those results, the angular momentum of psoas major was about 1.5-4 times bigger than other muscles. Therefore, we could confirm that the muscle force of psoas major is important for extension and flexion movement of knee joint. Namely, we could confirm quantitatively that psoas major is the most important to the hip joint movement in muscles around the hip joint.
  • 鈴木 慈, 福嶋 勇太, 安田 和弘, 保科 智啓, 田中 元基, 大橋 洋輝, 岩田 浩康
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    セッションID: A-3
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Hemiplegic patients cause a foot drop and cannot ground in the heel. Therefore the heel rocker does not work. In order to solve the problem, we developed the high-dorsiflexion support RT first prototype. However, the responsiveness of the artificial muscle is too slow to support the heel rocker. Therefore,we developed the high-dorsiflexion support RT second prototype which compensates the responsiveness by the spring system. We verified the effect of this device to the ankle joint the movement of the body center of gravity in the clinical trial. As a result, the second prototype can suppress the deceleration of the body center of gravity when the heel ground than the first prototype.
  • 鈴木 勝也, 種田 行男
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    セッションID: A-4
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The mechanical model of human body including muscle and tendon unit that is based on the Hill-type model is represented by use of Bond Graph method. From the result of calculation using this model, the coefficient for the characteristics of tendon length-tension relation is gained at the jumping motion. On the other hand, by use of the experimental data from Kawakami (Kawakami et al. 2012) instead of calculation results, dynamic muscle behavior at jumping motion derived from relative relation between muscle and tendon are represented as a dynamic loop on the muscle change length -tension characteristics. This analytical method is possible to be quantitative for tension change at repeated motion. This loop is also easy to understand dynamic characteristics of it by visualization.
  • 千葉 遥, 廣瀬 圭, 近藤 亜希子, 齊藤 亜由子, 伏見 知何子, 土岐 仁
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    セッションID: A-5
    発行日: 2015/10/30
    公開日: 2017/06/19
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    This paper deals with the motion analysis of carving turns in snowboarding by the measurement of reaction force from surface. The measurement system of reaction force from snow surface is installed to between the snowboard and bindings, and the system can measure the 6-axis force components from snow surface (force and moment) using the outputs of several 3-axis compact force sensors. We conducted the measurement experiment of carving turns by a high skill snowboarder. The results denoted the reaction force from snow surface vary from sec to sec. Furthermore, we compared the results of high skill and low skill snowboarders. The results denoted the difference of reaction forces by the difference of snowboarder's skill. The results can be used to clarify the mechanism of snowboard turns and to evaluate the snowboarder's skill.
  • 小池 関也, 須藤 眞吾
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    セッションID: A-6
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to investigate the availability of the inertial sensor during running motion through the dynamic contribution analysis of swing leg motion. During high speed swing motion in sports, motion dependent term is the great contributor to generating of the distal segment motion. Therefore, in order to develop a feedback system for immediate demonstration of motion generating mechanism, it would be efficient to use inertial sensor signals for implementation of dynamic contribution analysis. Inertial sensors were assumed to be attached on the thigh, shank and foot segments. Output signals of inertial sensors were estimated from the experimental data of running motion collected with a motion capture system (VICON-MX, 13-cameras, 250Hz). The swing leg was modeled as a linked system of three segments. Three types of analysis models and constraint conditions were proposed to investigate the effects of modeling on motion generating mechanisms. These models are model-1) three-dimensional model with hip connected to measred hip potision, model-2) two-dimensional sagittal plane model with hip connected to measured hip position, and model-3) two-dimensional sagittal plane model with hip connected to fixed point. The results indicate that 1) analysis of simple model (model-3) using inertial sensor outputs have the ability to evaluate he dynamic characteristics of the motion generating mechanisms, such as contributions of motion-dependent term and total joint torque term, and 2) accurate analyses on contributions of individual joint torques need time-curves of hip joint acceleration data.
  • 近藤 亜希子, 土岐 仁, 廣瀬 圭
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    セッションID: A-7
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The aim of this study is to establish the method for improving the performance of body motion analysis by inertial sensors. The position vector must be measured before the experiment in body motion measurements using inertial sensor. In the previous study, we developed the estimation method for the position information of the attached sensors. The method estimates the position vectors from the joint position to the sensor system by the centrifugal and tangential accelerations included to the accelerometer output. The method is established by the Extended Kalman filter. However, the method must hold on the base link for estimation of the position vectors. In this study, we developed a new estimation method of the position vectors from the joint to the sensor systems. This method is established by focusing to local coordinate system. The Unscented Kalman fileter algorithm is used for the estimation of the position vectors from the joint to the sensor using the two inertial sensor systems attaching the body segments. The proposed method can be used in actual body motion measurement. The method can be used to the development of more simply motion measurement method and the improvement of accuracy in the motion analysis by inertial sensor system.
  • 清川 拓哉, 野尻 紘聖, 大塚 弘文, 岩田 大助
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    セッションID: A-8
    発行日: 2015/10/30
    公開日: 2017/06/19
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    We analyze the pitching motion in early cocking phase, focusing on pronation restriction which causes pitching disorders. In consideration of disorders to develop in the elbow joint inside, we devise the parallel mechanism that simulated forearm skeletal system briefly. Furthremore, we suggest the estimated technique for pronation supination (pro-/supination) angle of the narrow sense and the rotation center axis vector using the motion capture system in order to evaluate pro-/supination in pitching motion analysis. It can apply to the posture estimation of other joints to estimate the rotation center axis vector with the posture change of the pro-/supination. As a result, the pronaton restrictuions were not seen in the subject, but confirmed elbow which fells down. This is caused by the fact that the kinetic chain between forearm pronation, elbow flexion and stretching up of arm was non-efficiency. Therefore, considering the results, it is necessary to clarify this kinetic chain between these motons, we will confirm the fact by increasing number of the subject.
  • 仲谷 政剛, 西脇 剛史
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    セッションID: A-9
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study is to investigate the influence of the shoe-sole bending stiffness on a mechanism of changes of ground reaction force (GRF). Five runners who were heel strikers participated and 4 types of shoes which inserted the different resin plate into the sole were used in this study. Several parameters during the support phase in the 2.78 m/s running motion, such as GRF, joint torques, and dynamic contributions and conversion coefficients of the joint torque of the support leg to GRF were calculated as evaluation indices. The results obtained from this study are that 1) the propulsion force just before toe off is the largest in the condition wearing shoe with CFRP, 2) this propulsion force change is caused by the ankle joint torque change, 3) center of pressure on the shoe coordinate system and the vector angle of GRF in the sagital plane, which are related with moment arm at the ankle joint, have different correlations with the ratios of sole local bending angles to the total forefoot bending angle. It is concluded that the consideration of the sole bending stiffness distribution is important to control GRF and COP in the designing process of running shoes.
  • 高桑 脩
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    セッションID: A-10
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In order to quantitatively evaluate running form focusing fluctuation of knee, position of the knee was measured by using high-speed camera and plantar load was also evaluated by using strain gage sensor during running on treadmill with speed of 4, 8 and 12 km/h. The obtained results show the knee periodically fluctuated crosswise direction during running and the fluctuation width increased with increase in running speed. In addition, the intensity of fluctuation of knee was related to fluctuation of plantar load.
  • 市川 将, 猪股 貴志, 原野 健一, 西脇 剛史
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    セッションID: A-11
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Recently, trail running on various surface conditions, i.e. uphill, downhill, wet, rock and so on, is getting popular year by year. In these surface conditions, it is predicted that load applied to the lower-extremity becomes higher during running on camber, which demonstrates the condition to run across sloped surface laterally. However, there are few studies that have discussed relationship between footwear stability and kinematics of lower-extremity in camber running. The purpose of this kinematics in camber running, motion analyses on three surface conditions (flat, CM: Medial side of the foot gets higher than lateral and CL: Lateral side of the foot gets higher than medial) were carried out. As a result, rearfoot eversion angle (β) in CL running and knee varus angle (ζ) in CM running become higher than those in flat running at foot flat phase. It was also confirmed that knee varus angle has a high correlation with rearfoot inversion angle in CM running. Furthermore, the influence of sole structures on β and ζ was also discussed.
  • 岡野 達哉, 前田 正登
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    セッションID: A-12
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to be found whether the ground contact motion is how to change when changing stage of running velocity. The subjects were the track and field club of 6 people in university. In this experiment, there was the shoe sole had been processed the thickness and inserted the sensor sheet which can measure the foot pressure. The subjects ran 10 to fifty-meters; subjectively increasing 10 stage of running velocity. The results were as follows. 1) With the increase running velocity, impulse in the ground contact were decreased. 2) With the increase running velocity, the ground contact time was shortened by the time until maximum 2 value was shortened. 3) After the ground contact, the center of foot pressure once moved rearward and then moved frontward. Also, with the increase running velocity, the moving distance from the rearward to the frontward was shorter gradually.
  • 工藤 将馬, 赤熊 亮祐, 藤本 雅大, 長野 明紀
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    セッションID: A-13
    発行日: 2015/10/30
    公開日: 2017/06/19
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    It is important for football players to efficently transfer mechanical energy generated by a whole-body kicking motion to a ball. The objectives of this study were (1) to quantify how much energy is transferred to the ball from the body during a football kick (energy transmission efficiency), and (2) to compare the energy transmission efficiency between experienced and non-experienced football players. 6 experienced and 6 non-experienced football players performed 3 types of kicks at 3 different intensities. Whole-body kinematic data were obtained by a motion capture system and ball speed was measured by a high speed camera. Mechanical energy of the whole body-during the kick and that of the ball after impact were calculated. The energy transmission efficiency was then defined as a percentage of the mechanical energy of the ball relative to the whole body. The energy transmission efficiency was found to be about 30% at a maximum, and the experienced subjects exhibited a higher energy transmission efficiency as compared to the non-experienced subjects. This suggests that energy transmission efficiency would be associated with football kicking skills, which could allow us to grade individual players at different levels in kicking technique.
  • 大前 佑斗, 昆 慶久, 酒井 一樹, 高橋 弘毅, 秋月 拓磨, 宮地 力, 櫻井 義久, 江崎 修央, 中井 一文
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    セッションID: A-14
    発行日: 2015/10/30
    公開日: 2017/06/19
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    For a swimmer, to enhance his/her swimming abilities, it is desirable for swimmers and/or coaches to understand and evaluate the characteristics of own swimming motions, such as strokes and turns etc. One useful method is to use a motion capture device. However, its device requires the high cost and complicated setup. On the other hand, the wearable sensors do not require them. For these reasons, we plan to develop a system to evaluate the characteristc of the swimming motions with a single underwater wireless wearable sensor. This system gives assistant information to swimmers and/or coaches. In this paper, we discuss the framework and requirements of the system.
  • 昆 慶久, 大前 佑斗, 酒井 一樹, 高橋 弘毅, 秋月 拓磨, 宮地 力, 櫻井 義久, 江崎 修央, 中井 一文
    原稿種別: 本文
    セッションID: A-15
    発行日: 2015/10/30
    公開日: 2017/06/19
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    We are engaged on a development of a system of swimming performance and technique evaluation with the aim of enhancing the swimming level of competitive swimmers. It evaluates performances of swimming motions (diving, strokes and turns) of a swimmer by using an underwater wireless wearable sensor attached on swimmer's waist. This system gives feedback to a swimmer/coach at the timings: (A) real-time, (B) end of swimming and (C) after training. To make these feedbacks by analyzing measured acceleration data, it requires an automatic swimming style classification. For the feedback at the timing (A), it has to classify the swimming style at each one stroke from corresponding part of data, and for (B) it has to classify from whole data. We examined the availability of the method of constructing a decision tree by dividing a feature space which feature quantities of each stroke are distributed in. After constructing the decision tree from training data and confirming the reliability of it, we assessed the availability of our method by F-measures of the result from test data. In our experiment, the styles freestyle and backstroke were well classified with high F-measure (greater than 0.95), but the styles breaststroke and butterfly were not well classified with not so high F-measures (greater than 0.72). This result means the evaluation for the feedback at (A) is still difficult to realize. However, it also means that this method is enough available for the feedback at (B) because the classification a this timing decides on a majority vote.
  • 高橋 美保, Todd Pataky
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    セッションID: A-16
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Recently, it has become social problem that lack of exercise cause the fall of physical strength and lifestyle-related disease. To solve those problems, various research has been conducted including the development of exercise game tools. But, those tools have various problems like indufficient feeling of achievement and limited movement caused by device restrictions. In this research, the first purpose is to construct a new exercise tool that has improved entertainment and portability. The second purpose was to test whether a 3D gaming environment could improve exercise performance compared to the identical game in a 2D environment. To measure game performance we used both a Nike+ in-shoe sensor which recorded foot accelerations at 120 Hz, and the actual on-screen reported score which was derived from the Nike+ data. A preliminary experiment and the sensuality evaluation using the SD method were carried out. As a result, it was suggested that there are some kind of causal association with the point of the game between visual factors.
  • 君塚 渉, 大貫 正秀
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    セッションID: A-17
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Relative to the measurement of a three-dimensional orientation of golf club head with one camera even if markers are put on any positions, we developed a jig which makes it possible to set a golf club at an intended standard orientation and a plurality of intended orientations quickle. The investigated setting errors of the jig were not larger than 0.1°. And, also, it is confirmed using this jig, it because possible to measure a head orientation relative to the intended standard orientation. Additionally, the following results are obtained. (1) The measurement error can be decreased by increasing the number of the head orientations considering the shaft angle change, but not decreased by increasing those considering the face angle change. (2) In case of setting considering the face angle change only, changing face angle with not 0° shaft angle makes the measurement error to be less than with 0° shaft angle.
  • 小林 龍太郎, 坂本 良太, 野村 由司彦
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    セッションID: A-18
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Pitching motion of baseball is split into several phases for analysis. Key frames that illustrated characteristic postures are shown with pauses when instruction using video is performed. However, manual cueing will be a burden for instructor and also requires time. Therefore, we developed a system which extracts five kinds of key frames for baseball pitching motion automatically by using a simple motion capture device. In addition, we evaluated the accuracy of the system. The system has extracted key frames except for a high-speed movement phase, which is a limit of the device.
  • 藤井 隆直, 鎌田 彩花, 中村 遼太, 加藤 智久, 中島 求
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    セッションID: A-19
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In order to improve comfort in bathing, the relationship between the biomechanical load and the bathtub shape has to be clarified. For this purpose, many bathing experiments had to be conducted since it was necessary to measure the reaction forces acting on a human from the bathtub experimentally. The objective of this study was to construct an algorithm to estimate reaction forces from bathtun in order to calculate joint torque as biomechanical loads without bathing experiments. This algorithm calculates distribution of reaction forces which minimizes weighted summation of i) sum of squares of reaction forces, ii) joint torques of hip and knee joints and iii) friction force of the back, considering gravity, buoyancy and passive elastic joint torque. Weighting were expressed as a function of bathing posture including parameters determined for each person to reflect influence of differences among the individual. In order to examine this algorithm, a bathing experiment to obtain the data of bathing posture and reaction forces for 10 subjects and 24 posture conditions was conducted. It was found that the estimated reaction forces were consistent well with the measured values.
  • 竹澤 聡
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    セッションID: A-20
    発行日: 2015/10/30
    公開日: 2017/06/19
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    This study illustrates a new strategy to fabricate arbitrary cross-section honeycombs. These types of honeycombs are usually manufactured from normal flat honeycombs by curving or carving, but the proposed method enables us to construct objective shaped honeycombs directly. We first introduce the concept of the kirigami honeycomb, which is made from single flat sheets and has periodical slits resembling kirigami (Japanese art of study folding and cutting). In previous studies, honeycombs having various shapes, including tapered and aerofoil honeycombs, were made using this method, and were realized by only changing folding line diagrams (FLDs). In this study, these 3D kirigami honeycombs are generalized by numerical parameters and fabricated using a newly proposed FLD design method, which enables us to draw the FLD of arbitrary cross-section honeycombs
  • 清水 雄一, 鳴尾 丈司, 柴田 翔平, 矢内 利政
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    セッションID: A-21
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In this study, we developed a system measuring bat behavior during a baseball swing by mounting an inertial sensor unit which incorporated the acceleration sensor and the gyro sensor to bat grip end. We compared the bat behavior that measured by between developed system and three-demensional motion capture system (MAC3D system; Motion Analysis). As a result, accuracy of the bat behavior calculated by developed system was varified. Furthremore, we defined eight parameters to express a characteristic of the bat behavior. In this way, players and coachers can evaluate baseball swing quantitatively. Eight parameters are "swing time", "swing speed (impact)", "swing speed (max)", "impact acceleration", "rolling", "bat radius of rotation", "bat angle" and "swing orbit".
  • 柴田 翔平, 廣瀬 圭, 鳴尾 丈司, 清水 雄一
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    セッションID: A-22
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to develop the analysis algorithm that is able to estimate the baseball bat trajectory in the practice swing motion and to examine the accuracy of the proposed method using 3D motion capture system. The measurement system in this study, which consists of inertial sensor system, measured 3-axis angular velocity and 3-axis acceleration. The sensor fusion using the extended Kalman filter compensated the drift error of the gyro sensor output and the error of dynamic acceleration of the accelerometer, and it estimated the 3D bat trajectory in a global coordinate by combining the sensor fusion and the compensation using motion characteristics. The measurement experiment was conducted to indicate the accuracy of the proposed method using 3D motion capture system. The 3D bat trajectory estimated by the proposed method corresponded with the 3D bat trajectory obtained by the 3D motion capture system. This result indicates that the drift error of gyro sensor and the error by dynamic acceleration are compensated. Therefore, the effectiveness of the proposed method was indicated and the proposed method can be used to evaluate baseball swing skill with high accuracy.
  • 大瀧 保明, 馬見塚 尚孝, 小島 一成, 藤原 聖司, 中野 勲
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    セッションID: A-23
    発行日: 2015/10/30
    公開日: 2017/06/19
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    This paper describes a method for characterizing baseball bat swing by using inertial sensors attached on a bat. The inertial sensor is consisted of a tri-axial accelerometer, tri-axial angular rate sensor (gyro) and tri-axis magnetometer. The inertial sensors were attached on the head of bat and on the tail of grip. Two healthy male subjects were participated in our study. One was skillful baseball player and the other was a beginner. Their swing motion was measured by camera based motion capture system and the sensory bat, in conditions of normal swing and with a load of 400 g weight ring on the bat. Experimental result showed that swing trajectories were different between skilled and unskilled subject. The difference was represented in measures of the inertial sensors as largar magnitudes of linear acceleration on the grip than that of the bat head during in a swing. Comparing normal and weighted swings, differences of swing timing were also detectable from the sensor data. This simple method using inertial sensors for bat swing evaluation is possibly useful for motion assessments outside of laboratories.
  • 小池 関也, 見邨 康平
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    セッションID: A-24
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to quantify the contribution of the whole-body joint torques to the generation of evaluation values during baseball batting motion, such as bat head speed and angular motion of the lower trunk in consideration of the joint torque generating mode. The whole-body segments and bat were modeled as a system of sixteen-rigid linked segments, and constraint axes of the elbow, wrist, knee and ankle joints were modeled with anatomical constraint equations in order to consider the degree of freedom (DOF) of the joint. Each hand was considered to be connected with the bat through zero DOF joint. The equation of motion with respect to the whole-body and bat was obtained by considering modelling errors, such as, residual joint force and moment, and fluctuation of segment's length. The dynamic contributions of the joint moments, motion dependent term and gravity term to the bat head speed and angular motion of the lower trunk were derived from the equation of motion for the system. Furthermore, the joint torque was divided into two components, such as eccentric torque component, which shows negative sign of its torque power, and concentric torque component, which shows positive sign of its torque power. The results obtained in this study showed that 1) motion dependent term was the great contributor to the generation of bat head speed and 2) major contributors to the generation of the bat head speed, such as concentric components of knob-side shoulder abduction torque and torso joint rotational torque were quantified by considering main generating factor of motion dependent term.
  • 城所 収二, 近田 彰治, 永見 智行, 矢内 利政
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    セッションID: A-25
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to examine the three-dimensional kinematic parameters of ball impact that cause the phenomenon of the lateral deviation of the batted ball. Nineteen women's collegiate softball players performed four "free-batting" trials with maximal effort to project the batted ball toward various directions; fly or line drive toward same field, grounder toward same field, fly ot line drive toward opposite field, and grounder toward opposite field. Behavior of the ball impact was recorded with two high speed cameras (1000 fps). Three-dimensional trajectory of the batted ball was calculated using the initial condition of the batted ball (velocity of the batted ball, spin rate, orientation of spin axis) immediately after impact. The projection angles of the bat on the horizontal plane (horizontal bat angle), the vertical plane (vertical bat angle) and the angle from horizontal of the line of impact (line of impact angle) were determined at the ball impact. Laterally-deflected distance of batted ball in opposite-field hitting (6.01±1.85 m) was longer than same field hitting (2.23±1.75 m). Meanwhile, within-group variance of laterally-deflected ratio (laterally-deflected angle per second) varied widely. The laterally-deflected ratio was correlated with the horizontal bat angle and the line of impact angle, but the vertical bat angle was not. The results indicate that the laterally-deflected ratio of the batted ball was increased by if the impact surface of the bat is facing toward the direction of the batted ball at the instant of ball impact.
  • 尾身 郁哉, 高嶋 優, 時枝 健一, 藤原 聖司, 新井 和吉
    原稿種別: 本文
    セッションID: A-26
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The metal bats are more advantageous than the traditional wooden bats due to their specific properties such as improved strength, lower cost, and durability. The National Collegiate Athletic Association (NCAA) only allows the use of bats whose Bat-Ball Coefficient of Restitution (BBCOR) is ≤0.50. Since there is a possibility that the value of BBCOR will be standardized in Japan as well, building the design method has become extremely important for controlling the value of the BBCOR. In previous studies, the BBCOR has been shown to decrease with an increase in the hoop frequency of the bat and the impact velocity of the ball. In this study, the equation for predicting the BBCOR from the relationship between the BBCOR and the impact velocity or the hoop frequency has been investigated by using a power law. From the BBCOR prediction equation, for an impact velocity of 61 m/s (as regulated by the NCAA), the hoop frequency in which the BBCOR is ≤0.5 has been determined.
  • 志村 芽衣, 宮澤 隆, 矢内 利政
    原稿種別: 本文
    セッションID: A-27
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to extract key impact parameters that determine the horizontal direction of batted ball trajectory in opposite-field hitting. Three-dimensional finite element analysis method was used to construct an impact model between a baseball and a wooden baseball bat, and a series of simulations with various bat swing direction and impact conditions were conducted. Horizontal bat angle was set -31〜20° and vertical bat angle was set 0〜51°, and each was analyzed at the 3° interval. The line of impact was set inclined in the range of 0〜40° with a 5° interval. The velocity and the angle from horizontal and from center line of the batted ball immediately after impact were determined for each simulated condition. The simulation model was validated by comparing the simulation outcome with experimental data obtained from opposite-field hitting practice performed by collegiate baseball players. The result showed that the horizontal angle of the bat at impact is the most impact parameter to determine the horizontal direction of batted ball trajectory in opposite-field hitting. In addition, the combination of the vertical bat angle and the angulation of the line of impact condition is also an important parameter. It is possible, therefore, to hit a ball toward a given horizontal direction with many different combination of horizontal bat angle, vertical bat angle and the angulation of the line of impact.
  • 田渕 規之
    原稿種別: 本文
    セッションID: A-28
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purposes of this study were to grasp th echaracteristics of the hitting sound for the rubber-ball baseball bats which evokes an image of longer batted ball distance and to investigate the difference of sound evaluation characteristics between rubber-ball baseball players and non-players. Tweleve kinds of hitting sound for the rubber-ball baseball bats were recorded for the sound evaluation test. Ten rubber-ball baseball players and ten non-players evaluated whether those sound evoked long distance or not by using Scheffe's paired comparison method. Though the sound evaluation score of rubber-ball baseball players and that of non-players showed significant positive correlation, each group showed the distinctive trend. Rubber-ball baseball players tended to feel the sound of the bats which hitting area are covered with foamed material as longer distance batted ball relatively, whereas non-players tended to feel the sound of the bats which hitting area are made with FRP. This result indicates that the rubber-ball baseball players acquired their sound image of the longer batted ball distance through their athletic experience.
  • 宮澤 隆, 志村 芽衣, 矢内 利政
    原稿種別: 本文
    セッションID: A-29
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to examine the factors influencing the position of "sweet spot (the impact position that maximizes batted ball speed)" of baseball bats. A finite element analysis was used to construct an impact model between a baseball and a wooden baseball bat, and a series of simulations were conducted with various bat swing speed and impact conditions. The simulation outcome showed two characteristic phenomena: One phenomenon is that, in the case of increasing the linear momentum of the bat, batted ball speed decreases when impact position offset from the node of bat 1st bending mode particularly the position that offset in the direction of the bat end. The other phenomenon is that, in the case of increasing the angular momentum of the bat, batted ball speed that impact position offset in the direction of the bat top from the sweet spot became higher than the speed when impact position is the node.
  • 正本 和人
    原稿種別: 本文
    セッションID: A-30
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Brain activation induced a local transient increase in cerebral blood flow (CBF). This phenomenon is known as the 'neurovascular coupling' in which the neurons and vascular cells are closely cooperated to maintain the adequate supply of CBF. In this talk, I will summarize the optical imaging techniques to visualize the cellular activity of the neurovascular coupling in in vivo rodent brains using two-photon laser scanning microscopy and a variety of fluorescent probes and proteins. To link these microscopic observations to the macroscopic diagnostic measures, it is also important to quantify the morphological and functional parameters of the cells. To test the hypothesis and to probe the casual link in the signaling mechanism of the neurovascular coupling, optogenetic techniques that enable us to modulate the cellular activity specifically with photostimulation, were introduced. The results of these experiments showed that the both neurogenic and astrogliogenic mechanisms participate in the CBF regulation of the neurovascular coupling.
  • 石川 昌紀, 信江 彩加, 佐野 加奈絵, 国正 陽子, 牧野 晃宗
    原稿種別: 本文
    セッションID: A-31
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The exploration of muscle mechanics during natural human locomotion is a continuous challenge. Ultrasonography is a technique, which can be used to study the fascicle and tendon length changes during movements. However, many of the ealier studies were unable to precisely identify how the fascicles behave in different muscles. This may have caused misleading generalizations. In addition, because the muscle spindles are located inside the contractile tissue, it is important to determine the role that stretch reflexes may play during rapid and intensive dynamic movements. Brightness mode ultrasonography has revealed that, in human locomotion, the nature of fascicle and tendon length changes varies depending on the task, contraction intensity, and the muscles involved. The findings emphasize that the active fascicles of the gestrocnemius muscle are suddenly stretched, although they are shortening. This short-lasting stretch triggers the stretch reflex, timing of which is dependent on running speed.
  • 中村 雅俊
    原稿種別: 本文
    セッションID: A-32
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In this organized session entitled "Usefulness of muscle hardness measurements using ultrasound elastography", we will demonstrate how to visualize the muscle hardness (shear elastic modulus) measured by ultrasound shear wave elastography (SWE) technique. The previous studies have reported that muscle hardness measured by SWE could provide an accurate estimation of individual muscle force and muscle activity level. In addition, in this study, we ingestigated the validity of muscle hardness measured by SWE imaging technique during passive muscle stretching in vivo, and a significant correlation was found betwen muscle hardness and muscle elongation. Therefore, the muscle hardness measured by SWE could be used to accurately estimate the stretching level. Moreover, we investigated the effect of static stretching on muscle hardness of medial gastrocnemius muscle and hamstrings muscle, and showed that the muscle hardness decreased significantly after static stretching. Therefore, muscle hardness measurement using the SWE technique was useful in determining the effects of static stretching.
  • 栗原 俊之
    原稿種別: 本文
    セッションID: A-33
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In this organized session entitled "An application of the sport and health science to the visualized form of in vivo information", we will demonstrate how to visualize the muscle activity in vivo by magnetic resonance imaging (MRI). It has been shown that transverse relaxation time (T2) weighted MRI of skeletal muscle demonstrates exercise-induced contrast enhancement that is graded with exercise intensity. This is because osmotically driven shifts of water fluid into the myofibrillar space. This study was conducted to show whether the exercise-induced MRI can distinguish the activity of small muscle such as intrinsic foot muscles. Eight subjects (age 22.4±1.1 years, height 173.1±2.7 cm, weight 64.9±4.3 kg) performed five sets of one-legged toe muscles were obtained and calculated T2 values by them. MRI is actually a noninvasive method and allows us to distinguish each muscle activity alternative to electromyography (EMG). T2 measurements of MRI can specifically provide direct information in each muscle activity.
  • 岡村 尚美, 築根 まり子, 小林 洋, 菅野 重樹, 藤江 正克
    原稿種別: 本文
    セッションID: A-34
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Muscle tone conditioning is important to prevent muscle disabilities in sports field. Static stretching is one of the most popular way to change muscle tone. To evaluate how muscle tone changes during static stretching, we have proposed a new method using a wearable muscle hardness meter and a viscoelastic model called spring^pot, and validated the method with the rectus femoris. Keeping one posture can stretch some muscles at the same time, but wearing many sensing devices should be avoided because static stretching must be performed in a relaxed state. If some adjacent muscles show a similar change of muscle tone, we can evaluate the stretching using only one muscle hardness meter. As a simple case study, this paper presents the similarities of muscle viscoelasticity at the medial head and the lateral head of gastrocnemius. We measred the muscle reaction force from the medial head and the lateral head of gastrocnemius during static stretching, and calculated the viscoelastic ratio as a hardness index. The viscoelastic ratio of the medial head and the lateral head of gastrocnemius changed similarly in two-thirds of the all trials. This result suggests the possibility of evaluation with one muscle hardness meter for muscle tone of the medial head and the lateral gastrocnemius.
  • 佐藤 晋太郎, 丸山 剛生
    原稿種別: 本文
    セッションID: A-35
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Muscle fatigue brings bad influence in everyday life. To prevent it from progressing, it is important that we control action by degree of muscle fatigue. So, goal of our study is to develop muscle fatigue quantification system that we can use it anywhere, accurately and easily. We develop following three things against previous study of muscle fatigue quantification. 1. To analyze degree of muscle fatigue anywhere, we use surface electromyogram as analyzing device. 2. To decrease subject's burden, we develop method that estimate characteristic of muscle fatigue by a few muscle contraction. 3. To decrease influence of data error, we add variable of stimulus target value. We performed comparison of value of muscle fatigue between experiment and simulation. In the simulation, degree of muscle fatigue is calculated by motor command level (Stimulus Target). We asked subject equal motor command level with simulation. But, calculated motor command level isn't very match with simulation. So, it is difficult to compare accurate precision between experiment and simulation. But, experiment result showed tendency of fatigue, and taking difference of motor command level into consideration, precision of quantification of muscle fatigue is almost good. We will aim at more accurate quantification of muscle fatigue and validation method of muscle fatigue model in the future.
  • 修行 雄大, 松田 昭博, 高木 英樹
    原稿種別: 本文
    セッションID: A-36
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In this study, effect of competition swimsuit on human body were investigated by musculoskeletal simulation. Recently, many compression sportswear were developed to supports the movement of human body. Improvement of athletic performance, reducing fatigue and promotion of blood circulation were expected by the compression sportswear. Applications to medical field are also expected. Competition swimsuit was designed to adjust human body strongly in sportswear to reduce the water drag. Positive effects of swimsuit on the start of competition were important issues. The uniaxial monotonic tensile loading tests of competition swimsuit fabrics were conducted to evaluate the characteristics of swimsuits. As a result, material properties of swimsuit fabrics were obtained and anisotropic was confirmed. The musculoskeletal simulations were conducted to evaluate effect of competition swimsuit on human body in diving start motion. As a result, reducing muscle force by swimsuit was found.
  • 林 祐弥, 大島 成通
    原稿種別: 本文
    セッションID: A-37
    発行日: 2015/10/30
    公開日: 2017/06/19
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    For the record improvement of the pole vault, athlete pole manipulation techniques and the characteristics of pole are closely related. Pole of manipulation techniques because of the complex operation and requires lot of skill. In addition, pole characteristic, it is necessary to select the one that matches the physical characteristics of athletes. In this paper, it is the simultaneous optimization of athlete skills and pole characteristics in the pole vault. Simulation software is used Open Dynamics Engine. ODE is capable of creating a rigid body of various shapes, because it operates at a high speed, it is effective for simultaneous optimization of athlete skills and pole characteristics. Competitor model to take into account the physical characteristics to create a musculoskeletal model, the muscle activity that controls muscle movement, and the release time as a variable. Pole model connects the 20 rigid body, and the resistance value and the total length of each of the connecting portions between the variable. These variables we are optimized with genetic algorithm.
  • 井尻 哲也, 木村 聡貴, 塚田 信吾, 中島 寛, 河西 奈保子, 住友 弘二, 柏野 牧夫
    原稿種別: 本文
    セッションID: B-1
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Different physical and mental conditions cause the human heart rate to fluctuate. However, it is difficult to record physiological data in real sports situations without impeding an athlete's movement, and no effective method has been established for quantifying changes in an athlete's heart rate that are unrelated to exercise intensity. Using a recently developed wearable bioelectrode ("hitoe"), we performed electrocardiographic and bodily acceleration measurements on two baseball players during actual practice and game situations. Analyzing the practice data, we constructed a linear regression model that accurately predicts each player's current heart rate from the previous 15-min acceleration data (R^2=0.86). Using this model and recorded acceleration data, we estimated the heart rates of the baseball players during a game. The results showed that the recorded heart rate deviated rapidly from the estimated heart rate relating to some game situations. Therefore, our proposed method effectively detected increases in the players' heart rates that were related to the game situations rather than to the exercise intensity, which could be interpreted as heart rate changes induced by the players' mental state.
  • 中村 遼太, 加藤 智久, 武田 宏二, 佐藤 稔, 中島 求
    原稿種別: 本文
    セッションID: B-2
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Although several previous studies investigated bathing comfort from the perspective of thermal effect or physiology, few studies investigated that from the perspective of biomechanics. The objective of this study was to ecaluate bathing postures from the biomechanical viewpoint. Bathing postures and reaction forces from the bathtub to a human was measured for ten healthy male subjects and in two bathtub conditions (new bathtub and conventional one). A three-dimensional motion analysis system and 3D force plates were used to measure the experimental data. A biomechanical model in which a human body is represented as a link of body segments was constructed. The torque due to buoyancy and passive elastic joint torque were considered in the model. The result showed that all the torque components due to buoyancy and gravity, reaction force, and passive elastic joint torque contributed to the joint torque and each torque component changed among bathtub conditions. In addition, joint torques on ankle and knee joints in the new bathtub were smaller than those in the conventional one significantly. These results suggest that the bathing posture in the new bathtub was more comfortable than that in the conventional one.
  • 相原 伸平, 田中 毅, 伴 秀行
    原稿種別: 本文
    セッションID: B-3
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Recently, wristband-type acceleration sensors are used in the fields such as health care and sports. However, from previous research, the body posture estimation by movement's strength is poor accuracy. In this paper, we developed the highly accurate estimation method with extracted various features from 3-axis acceleration data. Especially, we discriminated the sedentary or no sedentary behaviors which are typical low-intensity activity. Firstly, various features for machine learning were calculated from time-series acceleration data. These features were meaning the exercise volume and inclination with an arm. Next, the most suitable feasures combination was selected from among these features. Finally, sedentary or no sedentary behaviors were discriminated by a random forest using selected features. In the result, we achieved higher accuracy (more than 90%) than previous methods. This result proves that our method can estimate the body posture by arm movement easily and correctly. We would try to apply this method to the posture estimation of the athlete playing games.
  • 木村 聡貴, 井尻 哲也, 塚田 信吾, 中島 寛, 河西 奈保子, 住友 弘二, 柏野 牧夫
    原稿種別: 本文
    セッションID: B-4
    発行日: 2015/10/30
    公開日: 2017/06/19
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    It is not easy to measure electrophysiological signals adequately and comfortably in real sports environments since many conventional measurement methods, such as using wired electrodes, interfere with an athlete's actions. We have developed a conductive fabric called hitoe that enables us to solve this problem because the athlete wears it. This novel wearable bioelectrode has already been put to practical use for the continuous heart rate monitoring. In the present work, we studied a way of using this bioelectrode to measure electromyographic (EMG) signals during certain sports actions such as a golf swing and a squat movement. The EMG signals in multiple muscles were measured from bioelectrodes sewed into an athlete's clothes and were transmitted wirelessly through a compact amplifier. We found that our wearable bioelectrode could obtain EMG signals with satisfactory accuracy and evaluate muscle activities under natural sports conditions, although there were certain limitations as regards electrode location (change in muscle shape) and motion type (motion speed).
  • 高嶋 優, 尾身 郁哉, 時枝 健一, 藤原 聖司, 新井 和吉
    原稿種別: 本文
    セッションID: B-5
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The baseball's coefficient of restitution (COR) has been regulated by the Nippon Proffesional Baseball (NPB) for a regular season game in the first team of professional baseball players. If a ball impacts a rigid wall at 75 m/s, the ball's COR makes 0.4134 a desired value. The impact point of the ball is uncontrollable by the COR measuring method using a pitching machine. Since the surface form of a ball is not constant, it can be considered that the COR is influenced by the ball's impact point. In this study, the impact experiment of a ball for a rigid body wall was examined, and the ball's impact point was controlled using a light gas ball canon and a ball sabot. The effect of the ball's impact point on the COR was also investigated. The ball's impact points were the stitches part and the cowhide part (between stitches of the ball). As the results, the COR of the stitches part was higher than that of the cowhide part, and this difference increased with decreasing impact velocity of the ball. A t-test was performed to evaluate the difference between two CORs at a low impact velocity. Consequently, a clear difference was noticed between them. Furthermore, when measuring the impact load with a load sensor and deformation of ball, the absorbed energy was observed that the stitches part became lower than that at the cowhide part.
  • 北出 侑也, 酒井 忍, 伊藤 謙太
    原稿種別: 本文
    セッションID: B-6
    発行日: 2015/10/30
    公開日: 2017/06/19
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    It is difficult to shoot a ball of high speeds with horizontal and gyroscopic spins for a curently commercial table tennis robot (table tennis machine). In this study, the table tennis machine which can shoot the ball of various shot types (loop, smash, drive, knuckle, chiquite, etc.) was designed. The machine has tow launce and two gyro rollers, and the rotation direction and the revolutions of the four rollers are controlled independently. The shot performances of the machine were simulated using finite element analysis. In the shot simulations, various shot types inthe shot ball were confirmed. From the results of the shot experiments, the machine has high performance to shoot the balls of assorted spin types (top, back, side and gyro spins) with the maximum spin rate (over 12,000 rpm) and a wide range of speeds from 2.8 m/s (10 km/h) to 42.5 m/s (153 km/h). Moreover, the direction of the spin axis of shot ball can be selected as freedom the 360 degrees by the rotary control of two gyro rollers. The launcher mechanism and shot performance in the table tennis machine are described.
  • 坂本 誠
    原稿種別: 本文
    セッションID: B-7
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Use of metal baseball bat was allowed in the Japan high school baseball from 1974. Since a metal baseball bat has breaking little as compared with wooden bats, it is mainly used by high-school baseball. Many researchers are studied about the properties evaluation of a metal bat. However, discussion of sports injuries such as fractures and discussion of the major impact has not been done very completely imposed on the finger or the batter when using a metal bat. Then, in this study, the system which measures the impact load applied to a batter's fingers is built. And it aims at clarifying the impact force. After clarifying the impact load, the alarm about use of metal bats is sounded. Moreover, the simulation of a ball and a bat is performed using the finite element method, and it gropes for the method of easing a batter's burden from both sides of an exmeriment and analysis. First, a three-dimensional-CAD system is used and design and manufacture of an experimental device are performed. The system by which the impact load applied near the grip of metal/wooden bat are measured and evaluated is produced.
  • 湯川 治敏, 植田 剛志, 玉泉 範行, 河村 庄造
    原稿種別: 本文
    セッションID: B-8
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Shock attenuation property of sports surfaces is especially important not only for the athlete's performance but also for injury prevention. To evaluate the properties of the sports surfaces, some sports governing bodies often adopt friction tests and shock attenuation tests to determine the horizontal and vertical characteristics, respectively. Although the diagonal impacts are often observed in athletic sports, shock attenuation test only treats the vertical impact test. Therefore we developed a two-dimensional impact test device for examining the two-dimensional cushioning characteristics of sports surfaces in previous studies. To produce a simultaneous two-dimensional force against a test specimen, we incorporated a parallelogram linkage in the measuring system. In previous study, three different hardness of surfaces were examined for calculating the FR (Force Reduction) values not only the vertical component but also the horizontal component. As the results, Vertical FR values were increased with increasing the initial angle and impact intensity in all surfaces. And the different patterns of horizontal FR values were observed in these surfaces. In this study, we evaluated vertical and horizontal displacement by two-dimensional impact tests with high-speed video analysis. And we evaluated hysteresis properties of sports surfaces. As the results, horizontal properties of sports surfaces might depend on not only the material but also the structure of the specimen.
  • 小池 関也, 酒井 紳, 永井 悠樹, 高木 英樹
    原稿種別: 本文
    セッションID: B-9
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The take-off velocity of swimmer is generated by the forces exerted by the upper and lower limbs. Since closed loop problem exists between the lower limbs and starting platform as well as between the upper limbs and grip handle, it is difficult to implement kinetic analysis of lower and upper limb joints of swimmers during start motion. Therefore, the purpose of this study is to obtain joint moments by using an instrumented starting block. The block is equipped with two force platforms for measurements of forces and free moment exerted by the individual lower limbs and one grip handle containing two sets of 3-axis load cells for measurements of forces exerted by individual hands. By inputting kinetic data measured with the instrumented block as the exerting forces/moments of distal-end segment of individual limbs, inverse dynamics calculation can be implemented by using coordinate data obtained via three dimensional DLT analysis of swimmer during start motion. The result obtained in this study demonstrates that hip joints and shoulder joints show large extension moments during start motion.
  • 梅野 貴俊, 下戸 健, 日垣 秀彦, 岩本 英明
    原稿種別: 本文
    セッションID: B-10
    発行日: 2015/10/30
    公開日: 2017/06/19
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    Speed, agility, and quickness ('SAQ') are important components in most field and team sports but have not been extensively researched in terms of the technical skill of rapidly changing body direction. The purpose of this study was to examine the ability to change body direction rapidly with a reactive agility test. The research was conducted on a sample of 52 students from basketball teams in elementary schools, all females, aged 10.6±1.3 years. The results showed that agility (motion speed) in the anterior direction was comparable to that in the horizontal direction and was higher than that in the posterior direction. Additionally, the 20% of participants who took a basic dynamic posture stance were significantly faster than those who did not.
  • 右田 純生, 古屋野 浩志, 佐藤 史彬
    原稿種別: 本文
    セッションID: B-11
    発行日: 2015/10/30
    公開日: 2017/06/19
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    In 2014, the Japan Patent Office (JPO) carried out a technical trends survay based on patent applications in the field of exercise machines. The survey includes the analyses of technological development and proposals for future R&D strategy, which are based on the trends of patent application, scientific research and market. We expect that the result of the survay will be helpful for determining the direction of management and R&D. In this report, we present the overview of the survey.
  • 芦田 啓慈, 塩野谷 明
    原稿種別: 本文
    セッションID: B-12
    発行日: 2015/10/30
    公開日: 2017/06/19
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    The purpose of this study was to develop the object tracking system keeping the human movement or trajectory of ball in tennis using image processing. In this study, a dynamic field such as the human movement or trajectory of ball in tennis was extracted using the background subtraction, especially MOG model by mixed normal distribution which was strong in the fluctuation of the background and a change of the brightness by the break in the weather. As a result of having adapted itself to this algorithm, human (player) and the ball which were a change domain could be extracted.
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