In trail running, runners often meet slippery condition, such as uneven, wet, muddy surfaces with slope. On these surfaces, slip/fall risk gets drastically higher and running performance gets decreased due to traction loss between shoe and floor. Therefore, grip property is crucially important function in the designing process of trail running shoe. The purpose of this study is to clarify grip generation mechanism for trail running shoe designing based on uphill and downhill running (hill running) motion analyses. Ground reaction force (GRF) distributions in hill running were corrected by using a specific sensor shoe system. In comparison of GRF distribution between hill and flat surface running, higher horizontal force was produced in forefoot medial side area at kicking phase during uphill running. On the other hand in downhill, higher horizontal force got higher in lateral side of fore-midfoot area at the beginning of contact phase than that in flat surface running. Interestingly, it is confirmed that force direction of these areas was quite different between hill and flat surface running. In order to check the validity of obtained results, grip properties were evaluated with two pair of developed test shoes having different tread patterns. As a result, it was concluded that the oblique shaped tread patterns corresponding to horizontal force direction on hill running motion efficiently increase grip.

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It is known that a passive dynamic walk for a biped robot is stabilized by limiting its angle ofthe ankle of the stance leg. Since the passive dynamic walk has a similarity with a relaxed human walking, it is anticipated that the ankle angle limitation also contributes to stabilize a human walk. The purpose of this research is to realize this ankle angle limitation mechanism into human shoes, and investigate the effect of this shoes with the stabilization of human walk. In this paper, a simple configuration of the stabilized shoes is shown. In the shows, an angle of the ankle is limited by the attachment on a shin and a heel which are pulled together by a rubber sheet. A series of experiments were conducted to measure the stability of walking by recording integral EMG signals at the muscles that are known to posture control of a leg. The results showed that the muscles were less active during wearing the shoes with ankle angle limitation.

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In strength training, squat exercise is a representative example of lower extremity training. As target muscles of squat exercise are mainly knee extensrs and hip extensors, it is well-known that posture can effect on the main muscles activities. In addition, it is pointed out that injuries on squat exercise such as patellar tendinitis and low back pain are caused by the wrong posture. Therefore, it is important to design shoe function considering safety posture, effective load, and stability. However, athletes and trainee tend to do barbell squat exercise with various types of shoes such as weight lifting specific shoes, versatile training shoes, and indoor athletic shoes. Hence shoe heel-heights, which are derived from sole thickness difference between rearfoot and forefoot, are widely different from almost 0mm to over 20mm and might change the effect of training. The purpose of this study is to investigate the influence of the shoe heel-height on squat motion. Firstly the motion analysis was conducted and it was confirmed that low heel-height structure leads anterior projection of the knee and high load on knee joint. In contrast, high heel-height structure causes trunk forward tilting and high load on hip joint. Secondly, the relationship between experience of the exercise and shoe heel-height was investigated using beginner and experienced subjects. Judging from the results, it was concluded that shoe heel-height makes influence on squat motion especially posture and load for beginners and stability for experiencesd subjects.

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The purpose of this study was to understand relationship between foot temperature and comfort to design thermally comfortable shoes. Whole-body and foot temperatures, thermal sensation and comfort were measured, and also human thermal load was calculated under various walking speeds. The experiment was done under the thermoneutral zone and the unified clothing insulation. Through the experiment, whole-body and foot temperatures, thermal sensation and comfort changes were occured by mainly metabolism. As a result, whole-body temperature didn't substantially increase. However, foot temperature increased 2 to 3 degrees during the exercise period. Whole-body sensation had a correlation with foot thermal sensation. This relationship was due to thermoregulatory function. Foot temperature elevation also had a strong relationship with whole-body thermal sensation and comfort. Therefore, considering the thermolytic function of foot is important for designing thermal comfortable shoes.

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Soccer balls are constructed with 32 pentagonal and hexagonal panels. More recently Teamgeist 2 and Jabulani balls have 14 and 8 panels, respectively, with dramatically different panel shapes and designs from conventional balls. The latest model called Context15, made with 6 panels, has been adopted by 2015 FIFA Women's World Cup. However, there are few studies on the aerodynamic characteristics of these balls. This study examined the aerodynamic characteristics of soccer balls constructed with different numbers and shapes of panels. Results of wind tunnel tests indicated that the aerodynamic forces varied significantly according to panel shape, suggesting that panel shape has significant effects on the flight of the balls.

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It is said that there are some differences between wind tunnel test and flight test on the ball aero dynamics. The reason of the difference seems to come from an acceleration and deceleration or unsteady motion at the flight test. In order to confirm the differences, PIV measurements around a flying table tennis ball are conducted. The high speed camera which frame rate is 10,000, is used to capture the instantaneous motion around the flying ball. The imaging region is 210mm×210mm. A coordinate transformation to the ball fixed coordinate system well captured the wake motion of non-rotating and rotating ball. It is observed that at non-rotating condition, the averaged wake velocity field of the ball is symmetric. On the other hand at rotating condition, it is asymmetric. These observations quantitatively agree with the wind tunnel test.

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In order to evaluate ski jumber's performance, many researchers have been examined their flight paths by using the video based analysis. However, since the range of motion of the ski jump is enormously huge, the resolution and the accuracy of video-based analysis have been poor. For that, the authors developed a measurement system for the ski jumber's trajectory using an infrared red 2D laser scanner. This real time monitoring system continuously gives us the information of the flight path of the ski jumber during their training. Laser scanner could obtain the reflection from the target maximally 45 to 50m in our experimental setting. With the RFID tracking system, the automated obtained jumber's trajectories were easy to calculate its velocity and the acceleration. A particle system model was adopted to estimate the flight dynamics of the ski jump. The authors examined the drag and filt force of each ski jump trial from the obtained jumber's trajectory. Instead of the drag and lift force, the drag and lift area show us the change of the jumber's aerodynamics at the early flight phase. Around 1.5 to 1.6 second after the take-off, the lift area decreased steeply. It was assumed that the target location of the reflection might be continuously changed and switched from front to back, or from the body to head, etc., However, the advantage of this lase scanner system must be the instantaneous visual skill feedback to the jumpers and coaches with the flight trajectory right after their trial.

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This paper describes a process for optimizing the design of the landing slope of the Zao jumping hill. The features of the landing slope that we considered were the construction fee, the safety of the jumpers on landing, the length of the flight distance such that it makes it an interesting spectacle, and the difficulty for unskilled jumbers. We regard these features as objective functions. The findings can be summarized as follows: it is possible to control the four objective functions by changing the profile of the landing slope; the safety on landing is almost equivalent to the difficulty for unskilled jumpers; there is a trade-off between the length of the flight distance and the safety on landing and the difficulty for unskilled jumpers; the construction fee is influenced by the horizontal distance between the edge of the take-off table and the K-point; and the safety on landing, the flight distance and the difficulty for unskilled jumpers are influenced by the ratio of the height difference and the horizontal distance between the edge of the take-off table and the K-point.

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Ethylene-vinyl acetate copolymer (EVA) with low fabrication cost and good durability has been usually applied to shoe midsole as cross-linked foam material. However, in this manufacturing process, considerable waste materials such as powder after buffing have been also produced. Waste EVA foam could not be reused as plastic material or recycle plastic fuel (RPF) because of cross-linked and containing metallic compound. The efficient reusing method of waste EVA form is required. To achieve this objective, it is investigated that powdered EVA is mixed into rubber composite as light-weight filler. As a result, EVA powder has excellent reinforcing effect for low modulus rubber composite. On the other hand, high modulus rubber composite with EVA powder decreases the tensile strength. In this study, in order to establish the application method of EVA powder, the mechanical properties of rubber composite with EVA powder are precisely investigated. Based on the above results, the reinforcement mechanism of not only filler but also EVA powder is comprehensively discussed.

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In this study, homogenization finite element analysis of compression tests for rubber specimens with periodic hole structure to investigate the effect of microstructure on mechanical properties of foamed rubber. The rubber specimens were made by natural rubber and periodical holes were processed mechanically. The diameter to hole and distance of holes were supposed as constant to present relative density of rubber form material. For homogenization methods, biaxial loading tests of natural rubber were conducted to evaluate elastic potential function of hyperelastic material. In small strain region, numerical results of homogenized analysis showed good agrement with loading tests results. From the experimental and simulates results, possibility of homogenization analysis to rubber form material which have periodical microstructures were confirmed.

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In this study, stress contribution of sports spats in running motion was estimated numerically. The fabric of sports spats consists of the fiber which shows anisotropic and hyperelastic characteristics mechanically. Uniaxial monotonic loading tests for 3 types of fabric were conducted to estimate material parameters of anisotropic hyperelastic model. The 3D-CG human simulation was performed by using 3D-CG model to calculate strech of the sports spats. As a result, stress distribution of sports spats in running motion was calculated by performing 3-dimensional stress analysis. 3-dimensional stress analyses for the 3 types of submesh of material A, material B and material C were performed. Therefore, the influence that sports spats gave to body in running motion was clarified.

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Ski jumping is a sport which competes the flight distance and the flight form, and jumpers attempt to fly as far as possible. Ski jumping can be quantitatively treated from the aerodynamics point of view. The features of the ski jumping suit have an influence on the aerodynamic characteristics. In the regulations for ski jumping competition, the outstretched fabric must show a medium air permeability of a minimum of 40 liters per m^2/sec with 10 mm Aq differential pressure. However, the effect of the air permeability of ski jumping suits on the flight distance has not been completely clarified yet. The purpose of this study is to investigate three types of fabric with different air permeability from aerodynamic point of view, and the effect of air permeability of jumpsuit fabrics on the flight distance is examined. The wind tunnel experiments were carried out using the fabric clothed elliptic cylinder. The flight distance for each fabric was calculated with the aerodynamic force data assuming that the elliptic cylinder files.

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We examine whether gymnastic maneuvers on the high bar can be achieved by the control of inter-joint corrdinations described as constraints in a configuration space. Two gymnastic skills on the high bar, the kip moiton and Weiler motion, were modeled using a three-link model. The inter-joint coordinations were modeled as several linear functions of joint angles. The model was controlled by a feedback controller to track the desired coordination, which was sequentially switched among the several functions depending on the stage of a motion. Through numerical simulations, it was shown that the kip and Weiler motions on the high bar can be achieved by the control of the inter-joint coordinations.

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In this report, we aim to minimize body sway of a human standing on an electric skateboard by applying a feedforward control. A model of human during standing was defined as a thrid-order transfer function and the parameters were derived from the impulse response test and the frequency response test. As a feedforward control, we adopted an access control. The control method enables us to suppress the residual vibration during accelerating compared with the bang-bang control that is typical feedforward control. The accuracy of the model and the effectiveness of the feedforward control were verified by the rest-to-rest control test. To evaluate the ride comfort, we compared experimental result in the method with the simple constant acceleration. The result indicated that the advantage of the present method was not clear. As for modeling, we found the equilibrium angle of the human should be considered because it is not vertical during constant acceleration.

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We have already formulated a human three-joint arm's optimal control model with a freezing-like mechanism in its hand joint and clarified the model's effectiveness in reproducing two-point reaching movement characteristics. This research formulates a new optimal control model for reproducing human arm's obstacle-avoiding movements through incorporating two kinds of obstacle-avoiding conditions into the three-joint arm's optimal control model and examines the model's performance. The first condition is that the hand path is tangent at an avoiding time to the avoiding line that is parallel to the line connecting the start and final points. The second condition is that the tangent point, i.e., the avoinding point, involves the position of the obstacle deeply. Consequently, the following results are obtained: (1) the proposed model can generate obstacle-avoiding movements similar to measured ones under the two avoiding conditions and is superior in reproducibility to the previous model; (2) there exists the optimal avoiding time to minimize the model's criterion function; (3) the model's optimal obstacle-avoiding trajectories based on torque-change minimization agrees better with the measured ones than those based on energy minimization. These results suggest that the model's avoiding conditions can be valid in reproducing human arm's obstacle-avoiding movements and that the human arm's obstacle-avoiding mechanism can function based on torque-change minimization.

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The paper reports a result of dynamical system identification for a human standing control. The whole-body behavior is approximated by COM-ZMP (the center of mass and the zero moment point) model, where ZMP is manipulated so as to stabilize COM, and a piecewise-linear state feedback control. It is the piecewise-affine system model identification, which is a chicken-and-egg problem since the equation of motion has to be known for the parameter identification, while the parameters are required for choosing the equation of motion by which the state is ruled. K-means method and EM algorithm are applied to this problem. The result supports that COM-ZMP model with a piecewise-linear state feedback control well approximates the whole-body motion in stance. It is useful since it helps to evaluate the responsiveness and stabilization ability of a subject.

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The excursion patterns on center of pressure (COP) during golf swing are recognized into two types in skilled golf players. These are named "Front foot" and "Reverse" styles. In front foot style players, their COP travels smoothly from the back to front foot. While, in reverse style players, their COP showed similar excursion patterns to front foot style from backswing to early downswing, but it abruptly traveled to the backward just before the impact of ball hitting. It has never known which styles were beneficial for better performance especially repeatability of golf swing. The purpose of this study was to investigate the reproducibility of excursion patterns on COP during golf swing. Thirty nine skilled golfers (male = 22; female = 17) were participated in this study. They performed 10 driver shots with their maximum efforts. The locations of COP in medio-lateral and anterio-posterio directions (COPx, COPy) were calculated with ground reaction force. The reproducibility of the excursion pattern on COPx and COPy during golf swing was evaluated by coefficient of variation, which was the variation in COP at ball contact. There were two excursion patterns on COP in the subjects of this study and classified 21 players as front foot style and 13 players as reverse style. The coefficient of variation of COPy for front foot style golfers was significantly larger than that of reverse style golfers. These results indicated that the reproducibility of excursion pattern on COPy for Reverse style golfer was lower than for Front foot style golfer.

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The purposes of this research were to analyze body and club kinematics during golf putting and to simulate key features of that motion. The force differences between right foot and left foot at impact were analyzed between skilled and unskilled subjects, and these had significant differences (p<0.001): skilled subject had more evenly shared weight and smaller variability across putts. Before impact, skilled subjects had significantly different kinematics in the vertical trajectory from a simple pendulum, which was simulated in Simulink based on experimental data for club-head trajectory. We will investigate face angle stability to small kinematic perturbations when the dynamic putter model follows the experimentally measured trajectories of novice and experienced golfers.

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We aim to clarify balancing mechanism of the golf swing. In the golf swing, inertial and centrifugal force are applied to the player's body which have bad effect on balance. In such case, golf players carry out weight shift to keep balance. At first, we couduct dynamic analysis of the swing using the double pendulum model for arm al club in order to calculate inertial and centrifugal force and calculate the trajectory of the center of pressure due to the swing. And, we calculate the effect of the weight shift on the trajectory of the center of pressure using one mass model of the trunk of the player. Next, we carry out an experiment to measure the trajectory of center of pressure during golf swing by using the force plate. Comparing the calculation results and the experimental results, we discuss on the balancing mechanism of the golf swing. Through the discussion, it can be seen that the acceleration pattern of the human trunk plays very important role to cancel the effect of the inertial and centrifugal force of the swing and keep balance.

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In recent years, in research fields such as gait analysis, ergonomics and sport, video processing has been used. A high speed camera can observe a motion slowly. We can get an animation of a slow motion by taking a number of frames at the time of photography. A motion capture is also a technique to record the movement of a real person and object digitally. We visualize a movement of the kendo, and analysis a motion of the lower limbs during swing of an experiencer or a beginner. The measurement contents are velocity measurement of the tip of the shinai. Motion analysis of lower limbs and analysis of tendon motion by floor reaction force. There was difference in velocity of the tip of the shinai by a person with experience and an inexperienced person. In the motion analysis on lower limbs, it has been understood that power to step is five times larger than power to kick.

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A service choosing the best equipment for each player that is called 'Fitting' has received a lot of attention in golf market. However, Fitting is only conducted by experts called 'Fitters' who have special knowledge and experience. The one reason is that golf swing moitons are too complicated to systemize. Our objective is to reveal the complex swing motions and to establish a fitting system of golf shaft that can be used everybody who has not special knowledge. Firstly, we evaluated the validity of the calculated swing data using Design of Experiment and Response Surface Method to achieve our goal. It was found that the swing data were correct for 80% golfers their handicap is less than 40. Additionally, we developed a fitting system to choose the best golf shaft for each player and evaluated its accuracy. Using the shaft that the system recommended, 89 golfers of 103 improved their distance or direction or both.

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In order to hit golf balls correctly, golfers are particularly concerned with the characteristics of their drivers. Therefore, golf clubs are designed to satisfy golfers' demands. However, the United States Golf Association has placed restrictions not only on the volume of the club head, but also on the coefficient of the golf club under the spring effect rule. It is therefore difficult to differentiate these specifications. Golf club developers use a variety of methods to customize clubs to individual golfer. One such technique is "database fitting," established by Sumitomo Rubber Industries, Ltd. (SRI). In the future, golf club developers would like to provide shafts customized to fit each individual golfer. In order to do so, it is necessary to predict shaft movement during a golf swing via simulation. Previous studies simulating shaft movement during a golf swing demonstrate shaft movement using a finite element method (FEM) model. A head was attached to a FEM model of the shaft as a simplified ridig model. Moreover to take the golfer's grip into consideration, we modelled the grip using potential grip energy during the swing. Using this simulation model, we simulated shaft movement while taking into account the golfer's swing. And resolving inertia force into its component elements, we simulated shaft movement. The objectives of this study are to verify the influence of the component of inertia force on shaft movement while taking into account the golfer's swing.

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The rotation of the golf-club around the long-axis of the shaft may be generated by two mechanisms. The 1^<st> mechanism is the angular impulse exerted by the golfer around the long-axis of the shaft directly. The 2^<nd> mechanism is the change in the orientation of the long-axis of the shaft with respect to the angular momentum of the golf-axis of the shaft in golf swing. A golfer performed 5-trials of "place shot" toward target away from 2m of the golfer. The electromagnetic tracking device was used to measure the three-dimensional motion of the golf-club. The angular velocity around the shaft was 1938±211°/s in the direction of "closed face" at ball impact. The angular velocity attributed to 1^<st> mechanism was 3543±378°/s in direction of "opened face", on the other hand the angular velocity attributed to 2^<nd> mechanism was 5400±312°/s in direction of "closed face" at impact. These results suggest that the angular impulse exerted by the golfer around the long-axis of the shaft be important to control the direction of the face.

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This paper discusses multibody dynamics of serial link structure based on Jourdain's principle. The advantage of this method is based on differential geometry described by Jacobian matrices relating joint velocities and generalized ones without using angle definition of each segment. The method which utilize the velocity constraint and independently described generalized forces are suitable for understanding the physical meaning of whole body human movement.

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A spike jump in volleyball is important movement, but there are many unclear points yet. Therefore, in present study, we proposed some fundamental dynamics models using results of motion analysis to coach. Firstly, it was described that three things are clarified by using motion analysis. They are as follows: (1) only a forefoot is being used at spike jump, (2) kinetic energy of an approach run is needed to get big floor reaction force, (3) A human can accumulate elastic energy into own body. Nextly, we tried to explain some fundamental dynamic phenomena from above-mentioned results. these are "horizontal moving is changed to rotary motion", "dynamics model using spring and actuator" and "dynamic function of raising movement of arms". Finally, we discussed about relations between traditional coaching and mentioned above.

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In order to find a criteria of a double-leg circle for training, the variety of performance is considered based on the mechanism of a double-leg circle. As a result, this variety of a rotation around body axis comes from an existence of a horse body and its pommels as obstacles to be got over by legs. Especially, the relation between the tiptoe position and the hip twisting timing are important for this variation. The described performance for smooth movement for a double-leg circle is attained by synchronization between tiptoe position and the hip rotation around its axis.

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Most of multi-legged robots have same structure for each leg. However, thoroughbred horses have each different natural frequency in fore and hind limbs. In order to realize locomotion, each limb movement was required to have a same frequency. The aim of this study was to clarify frequency control mechanisms in equine limbs during swing phase. An energy-based analysis was carried out using variable moment pendulum model to all limbs. Our results show that the control of the energy change caused by the pendulum extension/contraction and rotational motion compensate for asymmetric dynamic differences between fore and hind limbs.

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We fabricated flexible humidity sensor which responds 10 times faster than commercial CMOS humidity sensor. Our sensor is based on Ionic-Gel-coated Fabric (IG-Fabric). We use EMIMBF_4 as ionic liquid and mixed with PVDF to fabricate ionic gel. The EMIMBF_4 has a characteristic that it absorbs H_2O. IG-Fabric has wide surface area and high gas permeability so that gases can be easily absorbed and detached. This sensor has many applications such as flu-mask-type human breath sensor, wearable sweat monitoring sensor.

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This study aimed to investigate effects of skin cooling on sweating responses during exercise. Healthy young men performed one arm elbow flexion with (COOL) or without (NORM) skin cooling on the arm during exercise. Skin cooling delayed the sweating onset time and decreased the amount of sweating on the active muscle during exercise.

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We measured and analyzed a mechanomyogram (a record of muscle sound, MMG) of a human's biceps brachii when it is electrically stimulated. The biceps brachii was stimulated by electrical pulses with an EMS machine. The frequency and the amplitude of the pulses were 5 Hz and 11 V, respectively. The MMG was measured with a wideband acoustic emission (AE) sensor attached between the two electrode pads of the EMS machine. The MMG and the EMS pulses were measured simultaneously to investigate the muscle response to a single EMS pulse. It was confirmed that the MMG induced by the EMS appears soon after the EMS pulse and disappears in about 30 ms. The latent time, contraction time, relaxation time of the MMG were about 7 ms, 12 ms, and13 ms, respectively and the waveform of the MMG is similar to that of muscle force when a muscle twitches by low frequency EMS pulses. This suggests that the MMG and the muscle force during the twitch have the same kind of information. A scalogram was calculated by continuous wavelet transform and it was demonstrated that the MMG induced by the EMS exists in a frequency range of 10-100 Hz. This indicates that the muscle fibers vibrate concurrently with the dimensional changes and the gross lateral movement of the muscle.

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We propose a precise altitude change measurement method by sensor fusion of sensitive pressure change sensor, which is based on MEMS differential pressure sensor, and commonly used pressure sensor. Precision of the fused pressure measurement was as high as 0.1 Pa. We measured the pressure change during walking up stairs.

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We developed the sensor system and method by using wireless motion sensor (WMS) installing inertial and magnetic field sensors to obtain the torque of each joints for the hitting action by the rugby-football player. This system consists of inertial and magnetic field sensors and force plate. We defined the 3D rigid link model of the rugby player, and constructed motion equations based on the Newton-Euler method. We measured the accelerations and angular velocities by using WMS sensors attached to upper body and lumber segments, and impact force by using force plate. The WMS and the force plate outputs were converted into the torque of each joints (the lumber spine joint, the both of hip joints and the both of knee joints). The behavior of the torque of each joints for keeping the posture of the rugby player in the hitting action was expressed qualitatively.

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A fracture of fifth metatarsal bone caused by playing soccer has been widely reported. However, the fracture mechanism of metatarsal bone has not been sufficiently clarified yet. The purpose of this study is to investigate influences of moves in playing soccer on the fifth metatarsal bone behavior by using motion capture and foot pressure measurement system. The experimental results showed that foot pressure under the fifth metatarsus bone of the pivot foot in a cross step motion and a cross kicking motion were heigher than that in inside step motion. Foot width got narrowed in the cross step moiton and kicking motion at proximal end fifth metatarsus bone. On the other hand, foot width got widend at the distal end. It is expected that identification of the mechanical behaviors in cross step motion and the kicking motion on to the bone stress distribution provides useful information to clarify the metatarsal bone fracture mechanism.

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In this study, Judo and American Football (AF) are spotlighted as typical physical contact sports that concussion or subdural hematoma could happen during a play. In Judo, "waza" to cause a risk to hit a head on a tatami were performed by Judo players and recorded by VICON system and the motions were reconstructed by MADYMO by using VICON data and kinetic data and hit part were generated. In Americal football, the moment of concussion was reconstructed by MADYMO by observing the accident data in real play recorded on a video and kinetic data and hit pat were generated. In both cases the strain and stress of the brain tissue were calculated in detail by the FE human head model and injury risk was predicted, respectively.

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The purposes of this study were to measure the ground reaction force in service ball bound and to investigate the index for the performance of tennis serve. To perform these purposes, following results were performed; 1) The ground reaction force of the ball and the rotary torque when a serviced tennis ball bounced were measured using a force platform. 2) For one of this result, about 350N of ground rection force toward vertical direction were confirmed. Furthermore, ground reaction forces of female subjects in this study were between from 200 to 300 N. And these of male subjects were between 350 to 500 N. 3) Ground rection force to the vertical direction will be the power of the service, and it may be the parameter to evaluate a service performance (without the unit) of no dimension until now. These results can be hopeful to the general performance evaluation of the service performance. 4) It is thought to e important to construct the experiment setting that it becomes the becomes the environment that is near (the measurement) by the real condition in future.

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In order to evaluate the joint moment of cycling motion, the pedal type sensor has been used as one of the load input devices. In the conventional pedal sensor developed in our group, there is a distance of about 40mm between the pedal rotation axis and the center of pressure point (COP). As a result, the measurement results are not strictly accurate. In order to obtain a more accurate result in higher accuracy, the distance of it must be smaller as much as possible. In this study, we developed a new type pedal sensor using two kinds of force-sensor-devices so as to minimize the above mentioned distance. Using these pedal type sensors, joint angle and joint moment were analyzed by applying the sports bicycle and the bicycle for people with disabilities. Moreover, the performances of these pedal type sensors were compared in this study.

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The steering wheel of the bicycle running and the acceleration of the saddle were measured. The tire inflation pressure was used to experiment as 800kPa in the bicycle frame of the chromium-molybdenum steel and the aluminum base alloy. The tire inflation pressure was assumed to be 450kPa in the cyclo crossing car of CFR P frame. The acceleration has increased as the running speed increases. The acceleration decreases by about 30% when making it to E150 of 150° in angle of the elbow as getting on posture for E180 of 180° in angle of the elbow. The acceleration of E150 in CRF P frame has decreased to 1/3 compared with getting on posture E180 in chromium-molybdenum steel frame.

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In this study, efficiency of pedaling in cycling was investigated with a newly designed cleat-shape biaxial load cells and free body diagram of lower limbs. The size of biaxial load cells is almost same as commercial plastic cleats (Shimano Corp.). These road cells allow cyclists to connect their cycling-shoes to pedals. The lower limbs model consisted of three segments, the thigh, the lower thigh and the foot. From the lower limbs model, all position of lower limb segments, joint torques and joint torque powers were calculated. Additionally, the relationship betweeen the ankle angle and normal force was proposed. This relationship does not require the image-analysis software with the high-speed camera.

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There are few studies have mentioned the influence of trunk muscles relates to a bicycle pedaling. In our previous research, we therefore intended to construct a measurement system for estimate the trunk muscle force using inverse dynamics calculations in bicycle pedaling. The system consists of measurement devices, (1) reacting force of the bicycle (pedal force, saddle force, handle force), (2) Pedaling action (pedaling posture, crank angle) and (3) Electromyogram (EMG) of right leg. In this study, these measured value obtained from the system were try to use in the inverse dynamics problemof bicycle pedaling. As a result, current model of inverse dynamics calculation is not well matched to the actual muscle force, and the improvement of the analysis model is required.

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Human motions are often measured by a motin capture system and approximated as motions of a rigid-link model for performing motion analysis. However, the relation between the motions of reflective markers on the body surface and the motions of the rigid link model is difficult to define, because of noise and modeling errors. We propose a simple and analytical method to estimate the parameters and motion of a two-dimensional closed-link model that approximates motion capture data obtained from bicycle pedaling. It was shown that the method can estimate the motions of the closed-link model whose joint positions were close to the motion capture data.

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The purpose of this study was to elucidate strategy for accurate throw by focusing on trajectory of free throw in basketball. The subjects were the six skilled basketball players belonging to a university basketball club and the recreational basketball player. The subjects were required to sink a free throw. The behavior of the thrown ball was recorded by four normal-speed video cameras placed beside the shooter and analyzed using the three-dimensional direct linear transformation method. The results were as follows: 1) Initial velocity ranged 0.2 to 0.6 m/s, and release angle ranged 3 to 9 degrees. This result differed from previous research. Then, it is necessary to consider including not only initial velocity and release angle, but also release point. 2) All subjects tended to change release point forward as the distance to the ring increased. In order to increase initial velocity, it is thought to push the ball longer and carry the ball in a straight line.

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We developed the set-form assist RT using auditory biofeedback to improve free throw performance. In the previous study, we found that the RT suppresses the set-form variability in the shoulder joint movement. However the free throw trajectories acqired by the set-form assist RT has not been evaluated yet. In this paper, we compared Pre-Post data in terms of (a) ball height from the ground when release the ball, (b) elevation angle of the ball, angular in horizontal of the ball (c) initial velocity of the ball. As a result, we found that variability on the ball height from the ground when release the ball and angular in horizontal were improved. However, variability of the elevation angle of the ball and initial velocity did not change. The results of multiple regression analysis showed that initial velocity was the most impact factor for free throw trajectories.

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The purpose of this study was to investigate a relationship between finger force and upper limb kinematics for baseball pitching. Two collage baseball pitchers participated in the experiment and threw a four-seam fastball 10 times. A force transducer was installed in a baseball to make a direct measurement of force imparting on the ball by index finger during pitching (2000 Hz). A pitching motion was captured using 12 infrared cameras (500 Hz). The finger force showed a bimodal pattern for both participant. The 1st peak appeared at a moment of maximum shoulder external rotation (45-50 ms before instant of ball release). The 2nd peak appeared at 7-8 ms before instant of ball release. It was considered that the 2nd peak reflected angular velocity of shoulder internal rotaion.

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The purpose of this study was to investigate kinematic changes in baseball pitching during a simulated baseball game. Six collegiate baseball players threw 15 hastball pitches per inning for 9 innings in an indoor laboratory with a 5-minute inning interval and 5-second pitching interval. Whole-body kinematic data were collected by a motion capture system and ball sped was measured with a speed gun. Pitch strength and Grip strength were also measured during each inning interval. No significant difference was found in the ball speed over the 9 innings, where the trunk was leaned forward in the later innings. The subjects demonstrated decreased pinch strength in the later innings althoug no such decrease was found in the grip strength. These results suggest that consective pitches would mainly affect pinch strength, which may not be a major determinant of ball speed.

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The aim of this study is to establish the method for the accuracy improvement of joint torque estimation in body motion analysis by wearable sensor system. The wearable sensor system consists of the wearable motion sensors and the wearable force plates, and the system can measure the 3-axis angular velocity, the 3-axis acceleration and the 3-axis magnetic field in the body segment and the ground reaction force. The wearable force plates measure the 6-axis force compontens in the heel segment and the toe segment. We established the method for calculation the resultant force of ground reaction force by considering the change of posture between heel and toe segments. The posture is estimated by using the Extended Kalman filter. The components about impact forces of force plates are used for the posture estimation. We conducted the measurement experiment of ambulation by attaching the wearable force plates, and we obtaned the resultant force (force and moment). The results indicated the effect by considering the change of posture between the heel segment and the toe segment.

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We investigated how the velocity of walking, jogging and running affects the 3-axis stress distribution at a human sole by using the measurement system assembled previously from eight MEMS 3-axis force sensors, amplifier boards and wireless communication module. The velocity was determined by using a treadmill and changed from 2km/h to 16km/h by 2km/h. In each condition, a series of 3-axis stress distribution data that corresponds to 30 steps on one foot was acquired. Peak value at each axis in each sensor position was evaluated from the waveform of every step, and the average of peak values was calculated in each condition of velocity and plotted in graphs. As plotted data were discontinuous between the velocity of 6km/h and 8km/h, they can be divided into two groups, walking group and jogging/running group. I both groups, there are strong correlations between the velocity and the average of peak values at each axis in each sensor position.

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The purpose of this study is to develop the gait analysis by using a motion sensor. Gait analysis is useful method for efficient physical rehabilitation and training of sport. In the past, gait analysis was measured by3D motion analysis system and force plates. Recently, gait analysis is measured by using a wearable sensor system, which is composed of a lot of motion sensor modules and ground reaction force sensor systems. This system is available everywhere and continuous walking. However this system is expensive price and take a long time to set. In this paper, a new estimation method for estimating walking state and ground reaction force of vertical direction by using a motion sensor is proposed. This system is low cost and easy to measure. From output of the sensor, walking state and ground reaction force of vertical direction is estimated by acceleration. Experimental study is carried out to evaluate accuracy of the proposed estimation system. Experimental result of the proposed system is confirmed to be valid.

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Walk analysis is enabled to use wearable gait analysis system without choosing the measurement range and the place. However an error is included in the output of the sensor. A shocking acceleration to occur at the moment when a heel grounds during a walk has a large influence on the attitude angle estimate of the heel. This result leads to a decrease in the precision of walk analysis. Therefore this study is suggested a method to control the decrease in the precision of the attitude angle estimate of the heel. First, when a heel grounded, we use an integral of the gyro sensor that there is little influence of the shocking acceleration. Second, the angle of the heel is corrected to 0 degrees at the foot flat. Finally, the error by a phase gap is compensated using a logarithmic function. The proposed method improves the precision of a heel attitude angle estimate in the walking.

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In this research, the effects of oar vibration on boat speed and comfort in rowing were evaluated. First, the significance vibration difference by two types of boat oar to the handle part was observed by modal analysis. And then, the oar vibration transferred to the front end of a boat on the feature when turning oar blade in rowing. Therefore, it was clarified that the relation between the boat speed by GPS and the boat vibration had a negative correlation. Secondly, the boat vibration by two types of boar oar was different, and then the large catch vibration by a type of oar was observed. Finally, it was clarified that the vibration effects on the comfort in rowing by a subjective evaluation on the simulation test by using a shaker.

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While the old yacht used only the drag of the wind, the recent yacht uses the lift force generated by both the sail (wing in the air) and the keel-bulb (wing in the water). When the ship heels, the keel-bulb makes the restoration moment and stabilize it. However, the trailing vortex generated from around the keel bulb is a problem. To solve this problem, it is necessary to know about the trailing vortex. In the wind tunnel experiment using particle image velocimetry (PIV), the flow around the keel-bulb is visualized. As a result, when given the angle of attack to the keel-bulb, the bulb rear end is confirmed two vortex larger in behind it, not only identified a single vortex.

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