We employ the take-off model with three degrees of freedom in order to investigate the optimum take-off angle in long jump. This model includes three parameters : take-off speed and angle, and also horizontal speed of the jumper's body which gives the effect of run-up. Based on this model, the initial speed of take-off is derived successfully as a function of the initial angle. Comparing the function with other ones, which have been obtained by measurements in shot put and long jump, we estimate the model parameter of the horizontal speed and finally obtain the optimum angle. The results show good agreement with the measured data, and this means that the three DOF model is effective as a model for take-off in long jump.

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In alpine ski races, suitability of design of ski boots is important to achieve accurate and quick lean of legs of ski racers in turns. This study is aimed at developing a new ski boots that can improve the results of alpine ski races for Japanese alpine racer. In this paper, the optimum range of the upper shell height for quick lean of a skier was demonstrated by utilizing principle component analysis. Finally, the effect of the new optimum range of the upper shell was verified in field test by Japanese alpine ski racer.

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The purpose of this study is to investigate relationship between shoe grip properties and running performance. To clarify the influence of the grip property, high grip (HG) and low grip (LG) typed shoes mounted miniature triaxial force transducers were developed. Isoprene rubber and polyester non-woven fabric were applied as outer sole materials in HG and LG, respectively. By using the shoes, distributions of lateral, longitudinal and vertical force components at 19 local positions were measured in running at 4.2m/sec. The experimental results showed that the distributions of traction coefficients, which is calculated from the horizontal force divided by the vertical force, were clearly different in HG and LG at 0-40% and 60-100% of stance phase. Furthermore, in comparison of ground reaction forces (GRFs) obtained from shoes with different grip properties, it was confirmed that lower grip property in both rearfoot and midfoot area decreased lateral GRF after heel contact and loading rate. Longitudinal GRF and traction coefficient were drastically decreased at 80% of stance phase by low grip in toe area.

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The purpose of this study is to evaluate from the side of utilization of the elastic energy by performing ankle jump to diagonal course while wearing sprint spike shoes and quantifying the elastic energy of the crural muscle-tendon complex . For these purposes, subjects performed a planter flexion jump (PFJ), a counter movement jump (CMJ), and a drop jump (DJ) using a slider seat system developed in this study, while wearing the several spike shoes. Furthermore in this study, we estimated the spring constant by performing ankle jump to vertical course. According the result, the increasing ratio of mechanical power was significantly correlated to the contribution of elastic energy and was observed that a ratio of LEMG of dorsal flexion for iEMG of plantar flexion is stabilizing in Long-plate type spike shoes. This result suggest that Long-plate type spike shoes may demonstrate high performance in the actual race.

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The purpose of this study is to obtain elementary information for sole designing in soccer boots. The grip property depends on cleats geometry and arrangement. The proposed technique with miniature sensors measures ground reaction force distribution. By using test boots with 19 cleats and miniature sensors, force components loaded on each cleats are clarified under the side step motion. Therefore it was confirmed that cleats under the ball area produced the higher vertical and horizontal rather than other cleats. Moreover ground reaction force distributions are measured by using the boots without ball area cleat. The effects of cleat deletion on cleats at the vicinity are quantitatively evaluated.

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From the unicycle riding experiment of human, pitching moment, rolling moment and yawing moment that generated by pedal control known to be exerted influence by attitude angle of unicycle, but control algorithm remain to be elucidated. This study tries that manufacture unicycle robot recreating pedaling control of human and recreates stability riding of unicycle by fuzzy inference. This paper reports on result of pitch angle control as initial stage of our work.

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We have formulated an optimal control model that reproduces human sitting movements on a chair. The model switches its dynamics at the moment (switching time) when its body sits on the chair, and optimizes its criterion function composed of three kinds of energy costs, a center-of-gravity cost, and an input cost. We clarify its fundamental performance in sitting on a chair and discuss factors indispensable for reproducing the same sitting movements on a chair as humans. Consequently, the following results were obtained : (1) experimentally measured sitting movements on the chair were successfully reproduced by appropriately adjusting the switching time ; (2) there existed the optimum switching time with respect to each sitting condition. These results suggest that the proposed model is effective as a model of the human sitting mechanism on a chair and that the switching time can be a factor involved strongly in human sitting movements on a chair..

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We have formulated an optimal control model that reproduces human rising movements from a chair. The model switches its dynamics at the time (switching time) when its body moves away from the chair, and optimizes its criterion function composed of three kinds of energy costs, a center-of-gravity cost, and an input cost. We clarify its fundamental performance in rising from a chair and discuss factors indispensable for reproducing the same rising movements from a chair as humans. Consequently, the following results were obtained : (1) experimentally measured rising movements from the chair were successfully reproduced by appropriately adjusting the switching time and the weight for the input cost ; (2) there existed the optimum input weight value with respect to each switching time. These results suggest that the proposed model is effective as a model of the human rising mechanism from a chair and that the switching time and input weight can be factors involved strongly in human rising movements from a chair.

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In order to realize stable walking by elderly people with supporting objects, we evaluated balance recovery capability by planar-shaped objects. Human arm and other body segments were modeled by a serial mechanism with seven dof and an inverted pendulum with a single dof. An evaluation index expressing capability of balance recovery by supporting object was proposed using these models. To formulate this index, manipulating-force ellipsoid of the serial mechanism and a friction cone (RFCS) at the contact point of the hand of human with the supporting object was integrated. Another index to express the degree of effective use of reaction force and frictional force was also presented. To obtain necessary parameter values to calculate the indices, experiments using motion capture system were conducted. An example of application of the proposed indices to determination of the height of supporting objects to help human to achieve stable walking with the help of supporting objects was shown.

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The surface of the rice-husk has a sharp irregularity. It contributes to an increase in the grip force to wet surface. Because, it depends on the rice-husk's breaking through the water screen. The rubber material with the rice-husk of the wear-out rate and coefficient of friction were measured. As a result wear-out rate became higher as the average grain diameter of rice-husk became smaller. The coefficient of friction became higher under wet condition than under dry condition when the addition of rice-husk to rubber. The wet properties of rice-husk reinforced rubber are increased on the contact area by the bend of the rice-husk.

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Excessive pronation should be controlled in not only running but also walking in order to enhance footwear stability. In the designing of footwear stability, it is important to clarify excessive pronation mechanism consists of foot and ankle movements. The purpose of this study is to clarify requirement properties for footwear stability in walking. To consider the excessive pronation in walking, ankle motion analyses on 5 surface conditions (flat, 2-side hill, down hill, up hill) were carried out. It was confirmed that maximum rear-foot eversion (β_<max>) and maximum tibia internal rotation (γ_<max>) in HC to FF phases were important parameters for stability function in walking. The relationship between γ_<max> and sole rear-foot torsional angle was discussed and γ_<max> obtained from shoes with various sole rear-foot stiffness were evaluated. In the result, it was clarified that small rear-foot internal torsional angle makes a good influence on footwear stability in walking.

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Recently "Ride" is described as the perception of running shoes in the international running magazine. But it is difficult to evaluate the "Ride" perception by physical measurements. The purpose of this study is to find the relation between the "Ride" perception and physical measurements for running shoes. In this research, good and bad "Ride" perception shoes are prepared. The running motions using these shoes were captured and the energy due to MP Joint Torque was calculated. The results showed that the "Ride" perception of the toe-off phase tended to depend on the energy loss due to MP Joint Torque. The analysis of the energy found the optimal construction of the grooves in forefoot of running shoes.

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In the designing process of footwear, it is important to consider requirement properties and establish the quantitative evaluation technique. Generally footwear stability which controls the excessive pronation has been quantitatively evaluated by foot joint angles, calcaneus eversion and tibial internal rotation. On the other hand, upper portion must be deleted to attach the reflective markers on the ankle in the current evaluation method. The purpose of this study is to develop the new footwear stability evaluation method without upper deletion. The new method focuses on the difference of medial and lateral midsole compressive deformations at the vicinity of MP joint. In order to check the validity of the proposed method, four runners with different contact patterns are used and motion analyses are performed. Therefore it is confirmed that the above difference can be an index to tibial internal rotation. Furthermore the application examples of the method to the practical footwear designing are described.

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Every running shoe has a function of preventing injuries, primarily achieved by its stability and shock-absorbing characteristics. These characteristics have been evaluated mainly in the respects of motion analysis and sole-material analysis, up to now. In addition, EMG analysis can be considered essential since muscular overuse is known to cause such injuries. This paper describes the relationship between shoe's stability and kinematics and EMG activity of lower extremity. Experiments employing 5 experiences runners revealed that activity of tibialis anterior could be effective for evaluating pronation, and activities of both fibularis longus and gastrocnemius would probably be useful for evaluating kinematics of the foot in the kicking phase.

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The purposes of this study are 1) to propose an evaluation index for the function of support leg joints during running under the conditions of wearing shoes with different sole properties and 2) to determine the influence of increasing sole bending stiffness on the function of support leg joints. We discussed about the methodology to select the optimal sole bending stiffness distribution for each runner. Four male runners participated and 4 types of shoes, which have different midsole bending stiffness, were used in this study. The contribution of joint axial torques to the acceleration of body CG (center of gravity) was derived from dynamics analysis. We defined a contribution index as the ratio of total torque contribution to the sum of leg joint torque contributions to the generation of the horizontal acceleration. Increasing midsole bending stiffness led to increasing the contribution of ankle planter/dorsal flexion torque to horizontal acceleration and MP joint planter/dorsal flexion torque to horizontal deceleration. Furthermore, the results indicate that the optimal bending stiffness of midsole, which improves the contribution index, may exist for each runner.

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From a prosthesis under cover to a one comes to light. Our common recognition has began to change through sports. For amputee's more beautiful form in running, we've developed prosthesis specially focused on usability, exterior, and safety. Here we introduce designs of prosthesis for lower limb, knee joints and air stabilizer for the carbon fiber foot.

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The purpose of this study was to develop a single-handed driving sports-specific wheelchair in order to improve a driving performance. To perform the purpose, NSB-07 for wheelchair basketball made by the Nisshin Medical Industries Company Limited was improved to a double ring typed single-handed driving sports-specific wheelchair. Two universal joints were used to transmit revolution of handrim in drive wheel. Furthermore, the EMGs from upper limb and the revolution velocity of handrim were measured when the wheelchair mentioned above was driven only one stroke by four driving ways which were double-handed driving, single-handed driving on both handrims, single-handed driving on handrim of left drive wheel, and single-handed driving on handrim of right drive wheel. In the result, It was indicated that a single-handed driving sports-specific wheelchair was have high driving performance by iEMGs of pectoralis major, biceps brachii, and anterior deltoid and revolution velocity of handrim on four driving ways.

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This paper introduced a new non-destructive procedure for visualizing a hand in a baseball glove using a 3-D computed tomography. Glove surface, hand in the glove and bone in the glove were visualized clearly. Furthermore, intra-examiner and inter-examiner reliabilities of joint angles and distances were comparatively high evaluated by the intraclass correlation coefficient.

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In baseball games, the most annoying problem for both players and audience is that the umpires sometimes make mistakes in their judges. We pay attention to a simulator system which can be used for educating and training those who want to be an umpire-in-chief. Constructing a simulator system consisted of a screen projection system and a computer, we conducted some experiments with the cooperation of some testees. In this paper we report our experimental results.

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Pole vaulting is a sport in which an athlete clears the highest jump heights achievable in a competition. A vaulter takes off and reaches a given height due to their kinetic energy and joint torque generated during the vault which is applied to the pole, and, as a result, gets height. Therefore, the height obtained changes greatly with combination of various parameters, such as the pole characteristic, vaulter's weight, takeoff speed, and torque of each joint produced by a vaulter. The purpose of this research is to determine the optimal solution of such a combination problem. In this paper, a flexible multi-segment pole model ,a three-dimensional vaulter model and a genetic algorithm are used to solve the optimization problem of the pole stiffness distribution and joint torque of pole vaulting. A complete system model is used to study the effects of different initial conditions and the effect of time variations in the control torques during the vault. From the results, it was clarified that there is optimal pole characteristic which is linked to the vaulter's initial velocity and weight.

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The purpose of this study was to propose a methodology to describe the dynamics of the whole-body and pole system during pole vaulting motion for the development of a pole vault simulator. The whole-body was modeled as a system of 15-rigid linked segments, and pole was modeled as N segments with elastic rotary joints. In the modeling of the whole-body, the constraint axes of the elbow, knee and other joints were considered. Each hand was considered to be connected with the pole through zero DOF virtual joint. The equation of motion with respect to the whole-body and pole was obtained from 1) the equation of motion for each segment, 2) equations for constraint condition in which adjacent segments are connected by joint, and 3) equations for the constraint axes of joints. We can calculate the forces exerted by each hand on the pole from the force vectors which is obtained in the process of deriving the equation of motion with respect to the pole vaulter and pole system.

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As a model for putting a shot, we employ the release model with three degrees of freedom which includes three parameters : shot putting speed and angle, and also horizontal speed of the shot putter's body. The three DOF model provides the explicit solution of the optimum release angle with the model parameters, and the solution is used for estimating the value of the parameters from measured data. Under the assumption that shot putters release a shot at the optimum angle, the speeds of putting a shot and the body are estimated. The result shows the distinct negative correlation between these speeds. Also, we attempt to clarify the difference between the glide and rotation techniques, and find that the optimum putting angle and the distribution of the body speed depend on the throwing techniques.

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The motions of a hammer are commonly regarded as a circular movement which a hammer undergoes around a turning human body. The distance of a throw depends on the speed of the hammer and the angle of its trajectory at the instant of release. The speed of the hammer increases gradually during preliminary winds and turns. During each turn the hammer rises up toward the high point of the trajectory and passes through the low point. Our interest in this study was to understand the mechanism of acceleration of the hammer in terms of parametrical excitation. The motions of hammer were analyzed to examine our theory using double pendulum model.

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It is needed to clarify the role of the golf club on the swing motion in developmental process. It is difficult to figure it out from the experiment that a lot of sample players test a number of different club models. Therefore, it is the rational procedure to use the numerical simulation. It has been proposed some models for the numerical simulation in past studies. The aim of this paper is to show the guideline in the select of the model to match the swing action of the player. We apply the two dimensional double pendulum models and propose the method to focus the relationship between the arm action and the wrist action. The result of the numerical simulation using the method is consistent with the result of the experiment. We show the effectiveness of the method.

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The purpose of this study was to understand characteristic of three-dimensional ground reaction forces in the golf swing. Eight right-handed professional golfers used their own drivers to hit standard golf balls in our laboratory. The swing motions were recorded using a 3D optical motion capturing system with a 200Hz frame rate, and three-dimensional ground reaction forces were captured by two force plates operating at 1000Hz on the floor of laboratory. Also, the center of pressure during the golf swing was measured. The angular velocity of the hips and the velocity of left hand were calculated as kinematic data. As for the results, movements of the center of pressure of both feet were small. The vertical ground reaction force in the right foot showed greatest when the hip changed the direction. On the other hand, maximum vertical ground reaction force for the left foot showed at the impact.

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An easy and economic system to automatically diagnose golf swings has been developed. The system takes 180 photos and selects 12 images required for diagnosis of the golfer's swing. Swing positions are detected by extracting the body silhouette in selected images and identifying colored marks on clothing. Results of the analysis are then compared with a standard swing. The system then generates suggestions for improving the golfer's swing, as well as, practice method recommendations.

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We are developing a system to confirm 3-D coordinate (x, y, z, t) of golf ball flight trajectory by using video camera image. Information of tilt θ _c(t) and pan φ _c(t) angles of the camera are detected by two rotary encoder. The absolute distance r(t) from the camera to a golf ball will be detected in relation to the number of pixel area of a golf ball on the screen. The center position of the golf ball on the screen is transformed into the tilt θ _s(t) and pan φ _s(t) angles of the camera, then they revise θ _c(t) and φ _c(t). Finally, 3-D position (x, y, z, t) of the ball are decided from spherical coordinate system (r(t), θ(t), φ(t)).

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The sound simulation program estimates the sound radiation. It has been developed in our laboratory. A past research estimates the ball impact sound of the golf club. As for past research results, the difference was seen in "Sound collected by the excitation experiment" and "Sound that had been calculated by the sound simulation program" in the driver of the golf club.Therefore, the accuracy of the program is confirmed and improved in the present study. Then, it is preferable to be able to understand the accuracy of the program precisely. The experiment and the calculation are compared by using the plate and the cylinder with few error margins of the finite element model, and then, this research compares, and examines the surface vibration velocity and the sound pressure. As a result, if the error margin of the finite element model is few, it has been understood that the straight advancement sound from the surface vibration velocity and the surface vibration velocity is correctly computable. And, the influence of the diffracted sound was able to be experimented.

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We was investigated the relationship between viscoelasticity and impact resilience. The polybutadiene rubber was kneaded several kinds of additives. Then they were made to vulcanize it in the press machine and the film was made. A dynamic mechanical thermal analysis and static tensile test was measured with the film. We examined the influence that the film making condition gave the viscoelastic property.

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This sheet deals with analysis of the oblique impact system, which is composed of the golf-ball and club. The impact system is modeled by both a nonlinear spring and a nonlinear dashpot using Hertz's contact theory. This model is applied to the oblique impact system of ball. The characteristics of the oblique impact were obtained by using this model. In previous studies,the validity of the normal model was confirmed, validity of tangential model was not confiemed. Therefore, reconsider the tangential model. The result is improved accuracy of the model.

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The objective of this study was to grasp the relationship between clubshaft positions and the rebound of a ball, and to investigate the factor of the relationship using a finite element (FE) analysis on a ball colliding with a simplified club. The clubs were constructed by holding simplified clubheads in a locking ring fitted onto a steel shaft. The clubheads were designed with reference to the mass, volume and position of centre of gravity (CoG) of commercially available clubheads. FE models with linear elasticity of the clubs were constructed. The FE model of the ball consisted of 8-node solid elements, and the material model was expressed as a hyperelastic/viscoelastic model. Impact experiments were also conducted for comparison to confirm the accuracy of the FE models. The results of impact simulations closely matched the experimental results. The ball rebound was analysed using the constructed models by varying clubshaft positions to the CoG of clubhead. The rebound behaviour of the ball tended to be strongly depended not on the clubshaft positions, but on the characteristics of the clubhead in the case of a collision with the sweet spot of a clubhead. In the sole and crown impact cases, the ball rebound were varied with the shaft positions and the variation seemed to be influenced by the impact force of direction parallel to the axis of shaft.

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Human tympanic membrane vibration induced by sound is transmitted to a cochlea via auditory ossicles and stimulates an auditory nerve. Therefore, the detailed study of the tympanic membrane motion is necessary to elucidate mechanisms of human hearing. In the present study, the sound-induced vibration of tympanic membrane was measured by using a laser doppler vibrometer and the optical system of a surgical microscope in three normal hearing human subjects at six sound frequencies. The vibration was measured at the center of the tympanic membrane, the center of the area of the light reflex, the center of the opposite area of the light reflex, and the center of the area of the tens part. Experimental results show that the amplitude of the vibration at the center of the tympanic membrane is smaller than that of the other measuring points. This is important because it provides a crucial information to create better vibration models of the tympanic membrane.

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In this study, bone strength evaluation method using a response of hammering test was considered. In the method, transfer function of the bone is measured, and the response level which is stable at lower frequency of first resonance is obtained. On the other side, a relationship function between the response level and bending stiffness of the bone using theoretical beam vibration model is calculated. After then, the bending stiffness of the bone through the relationship function and the obtained response level is estimated. For the verification of the method, bending stiffness of some test pieces, which bending stiffness were already known, were estimated by using this method. As results, the obtained bending stiffness was very close to the actual value. From these consideration and experiments, the method is considered to be a suitable bone strength evaluation method.

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The person who injures his cervical vertebra in the traffic accident goes up to about as many as 500,000 people a year, and immediate clarification is requested in recent years. To clarify the cervical vertebra sprain, the present study executed living body information on electromyogram and a movable angle and questionnaires of NDI and the accident situation, etc. for the patient with the traffic accident. The tracking experiment of one testee who appealed for the pain to the monk cap muscle side after 487 days was executed three times in the experiment 155 days later 47 days after the wound of receiving. The NDI value would decrease in 487 days as a result of the experiment, and electromyogram showed the change. Moreover, a movable angle of the neck showed the increasing tendency.

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There are mainly two kinds of diseases in intermittent claudication. One is lumbar spinal canal stenosis (LSS) and the other is arteriosclerosis obliterans (PAD). Whether differentiate LSS or PAD is critical issue. Concerning above, this paper presents a novel approach for classification of intermittent claudication from walking motion. We measured the walking motion by camera and track the LED markers in the walking on the treadmill. Then we can get the information such as joint angle trajectory and hemi-foot step. We investigated about the differences among the walking motions of healthy person, LSS patients and PAD patients. It has been revealed that the average of ankle joint angles and hemi-foot step can be used for the diseases differentiation. As the method of diseases differentiation, The SVM has been applied to make the boundary to divide the disease areas. From the differentiation test using the measured data, the availability of this method has been confirmed.

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In previous studies, we proposed a variety of models of material and methods for identifying the parameters of these models by multi-intensity impact test. In particular, the exponential model (Kobayashi & Yukawa, 1998) shows excellent accuracy in identifying the properties of material behavior. Although other papers reveal that this model is applicable in cases of varying impact duration and various temperatures, we have not yet discussed how the properties would change as the impact area changed. The purpose of this study is to propose an identification technique of nonlinear Voigt model with hysteresis and dependence on impact area by multi-intensity multi-area impact test. The nonlinear elastic element of this model is expressed by the exponential function based on displacement and impact area. And the nonlinear viscous element of the model is expressed by the product of the exponential function based on displacement and the exponential function based on velocity.

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The purpose of this study is to investigate a viscoelastic model which can generate two dimensional ground reaction force in steady pace running. In previous our studies, we had proposed 3 degrees of freedom viscoelastic model which could generate not only the vertical ground reaction force precisely but also the rebound velocity which is almost same as the rebound velocity in experiment. According to the angle of the ground reaction force calculated from the ratio of vertical and horizontal ground reaction force during contact period, the model should have a rotational control element because the rotational behavior of the model showed a complicated movement. Therefore, the nonlinear rotational elastic and viscous elements were incorporated to the model for governing the rotational behavior. And the parameters of the model were obtained with parameter searching. In conclusions, there were some significant error between the experimental data and the simulation conditions though, the two dimensional ground reaction force was reproduced with the proposed model.

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Because the amount of traffic increased in the Tamagawa cycletrack for the runner boom and the bicycle boom, and the bicycle accident happened frequently with the pedestrian and the runner, the barrier in the cycletrack was investigated. It ran 23 km/h±2km/h in average and 1200km in total in the Tamagawa cycletrack by bicycle, the acceleration was measured with three axis accelerometer installed in the right wrist, and it took a picture of the video image at the same time. The results of measuring the acceleration of the Tamagawa cycletrack when running were 20 m/s^2 on the average and maximum value 205m/s^2 by the crack part of the road. Steps that had been set up for the speed control of the bicycle were observed to cause the speed decrease on 3.5 km/h average with the road bicycle.

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In our previous study, DIN standard test was found to be inappropriate to evaluate the shock absorbency of long pile artificial turf (3-g turf), in particular for acute, high loading likely caused by human sports action, and a new testing procedure which precisely reproduce that load has been proposed as a better mechanical test. In the present study, therefore, an attempt was made to measure more representative shock absorbency of 3-g turfs (different infill components combined with shock pads) using that testing procedure. Also the shock absorbency of 3-g turf was compared with that of natural turf using acceleration change of the impact head of the test rig. Several types of 3-g turf tray with different infill: sand, rubbers (large, medium and small grain), sand/rubber and new type (shallow infill with underneath shock pad) were tested, and those combinations with underneath shock pads (rubber/urethane combined and polythene foamed) were also tested using the new testing procedure. In contrast to our general understanding, most types of 3-g turf (untouched condition) showed a smaller peak acceleration and a milder jerk than those of the natural turf. Moreover, a 3-g turf with unusual infill component with rubber shock pad demonstrated a quite similar jerk with that of the natural turf. This result may reinforce the needs for reconsideration of appropriate shock absorbency for 3-g turf.

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We have developed a mobile force plate (M3D) and 3D motion analysis system by integrating small triaxial force sensors and 3D inertial sensors for estimating multi-axial GRF and orientations of feet during successive gait movements. In order to verify the measurements of the developed system, we used a stationary force plate as a reference measurement system to simultaneously measure the triaxial GRF and center of pressure when a subject was required to wear the M3D. Static and dynamic test experiments were implemented to validate the triaxial force measurement of the M3D. Experimental results verify that the developed system can be used to measure the triaxial force with acceptable precision An application trial for going up stairs was carried out using proposed system and wearable 3D motion sensors which we have developed.

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Sprinters adjust the arrangement of their starting blocks prior to a race, but there is no clear standard for arranging the blocks. It is unclear at present how the arrangement changes the forces applied to the blocks and consequently affects performance coming off them. The purpose of this study was to investigate the effects of the arrangement of the starting blocks on the forces applied to them. Forces applied by a sprinter to the front and the rear starting block as well as to the ground on the first step were measured using three force platforms for 18 different arrangements of block spacing. The results indicated that the amount of the impulse applied in starting posture to both the front and rear starting blocks changed little between the 18 arrangements. Likewise, no substantial change occurred in the forces applied to the ground on the first step. However, as the distance between the front and rear blocks changed, the ratio of the impulse applied to the front and rear blocks changed : as the block spacing was increased, the impulse applied to the front block during starting posture decreased while that at the rear block increased. In addition, changing the distance from the starting line to the front block influenced the relation between the block spacing distance and the forces applied to the two starting blocks. It was thought that in response to changes in the position of the starting blocks, the movement of the legs varied, with one leg compensating for the loss of force of the other leg, and thereafter there was no substantial change in the force applied to the ground on the first step.

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The purpose of this study was to study the effect of impact velocities on the passive impact forces of the whole foot and heel part during rear foot strike running. Three healthy male subjects performed three sets of barefoot running at self-selected normal, slow, and fast speeds to get running data. A simple mechanical model consisting of two masses, linear springs, and dampers and nonlinear spring which could consider contact phases of running and contact points: the heel and toe parts was used to simulate vertical ground reaction forces. Sensitivity analysis was done by changing impact velocities. The results showed that the peak passive impact forces of the whole foot and the toe part had a different tendency. Furthermore, the average vertical loading rates of the toe part ground reaction were higher than those of the whole foot ground reaction force in spite of their similar tendency.

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Rugby Tackle is an only method for defense to attack. It is necessary to clarify the motion during tackle to know effective tackle. The purpose of this study is to clarify the characteristics and difference of tackle motion among different competitive levels by analyzing tackle motion of rugby players belonging to high school, college, and professional. In this study, tackle form was especially investigated and compared. Subjects ran enough, landed on the force plate, and tackled on the tackle bag on which an acceleration sensor attached. Impulse of the tackle bag increased as the competitive level increase. The angle of truncus to direction greatly changed in professional players compared to high school and college players. The average angle of truncus to horizontal plane was smaller for the professional players at Foot Contact phase, almost same at Tackle phase, and bigger at Foot Off phase. Distance between stepping position and the tackle bag was longer for professional players. Therefore, it can be considered that professional players could change those truncus angles after Foot Contact.

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Blood pressure pulse waves are propagated from the heart to peripheral with changing their shapes according to characteristics of pass way. A characteristic of total arteries can be detected from pulse waves as an arterial stiffness. Some diseases, like an abdominal aortic aneurysm, can be predicted if some deformed pulse waveform of specific arteries are detected. The aim of this research is to propose new method to detect such diseases. A pulse wave propagation model based on an arterial tree can help to analyze the cause of deformed pulse waveform. In this paper, the propagation of pulse wave characteristics is theoretically analyzed and new method to detect the diseases is proposed and verified in the simulation.

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Anaerobic Threshold (AT) is defined to an exercise of the maximum workload when it can be performed without the continuous blood lactate concentration rising while the gradual increasing exercises. AT is widely used as an index of the safe and effective exercise workload in exercise therapy. To determine the AT, the blood lactate measurement with blood sampling or the ventilation measurement is needed. The blood sampling can not be performed except the medical licensed doctor or nurse, the ventilation measurement is needed a very expensive device. The purpose of this study is to make the procedure to estimate the AT using the vital signals such as the breathing curved line (BCL). From the preliminary experiment (Experiment 1) result, the BCL was focused as the index for AT estimation in this study. In experiment 2, the rapid increase of the ventilatory volume (VE) in which AT was made a boundary tried to limit the breath frequency from the point of depending on the frequency of breath.

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It is thought that the rescue can be helped by understanding the car occupant's heart beat and breath at a traffic accident. It went in real time in the noncontact method for measurement of the heart beat and breath by installing the sensor in the car seat, and using the micro wave in the present study. As result, the heart beat and breath were able to be measured from the car occupant in real time in one minute in the measurement time. It will be thought that this technology can be applied in a wide field only equipped with the car in the future.

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In general, the enhanced electromyographic activities were involved in increased metabolism of those muscles. In this phenomena, percutaneous oxygen saturation, such as the oxygenated and deoxygenated hemoglobin, shows certain changes in muscle. It was expected that the changes in the percutaneous oxygen saturation represented the phasic pattern in ankle synergistic plantar flexor muscle group, soleus muscle and medial gastrocnemius muscle. However, there were no results about changes in the oxygen saturation pattern for its antagonistic muscle, tibialis anterior muscle. The purpose of this study was to clarify the relationships within the oxygen saturation between agonist and antagonist muscle relative to the EMG activities during upper and lower limb different motor tasks.

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Stress means the distortion of the physical or mental condition, which is caused by various stressors. Various countermeasures are needed against stress because the distortion of the physical or mental condition causes various physical and mental illnesses. The purpose of this study is to create the concept design of a floating biofeedback system for mental management and health. Supine floating was adopted as the floating method for the system. For the purpose of this study, the effect of supine floating on the autonomic nervous system was investigated experimentally. Subjects underwent 2 types of relaxation. One was the supine floating in a swimming pool. Another was the supine on the matt. ECG data during the each supine was measured, transmitted to a computer, and transformed into a power spectrum by FFT. Furthermore, the breathing curved line in each supine was measured by the thermistor. The new concept design of a floating biofeedback system was created based on this experimental result.

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In this study, we investigated how visual feedback regarding pinch force for left and right hand contributes to maintaining and controlling constant force amplitudes. In the present pinch tasks, participants were asked to maintain target pinch force levels for left and/or right hand of 5 or 10% maximal voluntary force (MVF) for 20 seconds. The target amplitudes and current amplitudes of left and right pinch force were displayed with visual cursors. In no visual feedback conditions, one or both side of the cursors disappeared 10 seconds after beginning of the task. Results showed that errors of the pinch force increased as time from disappearance of the feedback cursors, and that variability of the pinch force increased immediately after the disappearance. The errors and variability of the pinch of 10% MVF in no visual feedback condition became largest when accompanied with the pinch of 5% MVF in no visual feedback condition. One side of pinch force with no visual feedback showed better control performance when the other side of visual feedback was available. These results suggest that only one side of the visual feedback aids the maintaining performance of the pinch of the other side with no visual feedback in executing bimanual pinch movements.

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Tiredness by the car driving for a long time examines the extraction and the tiredness of the influence that causes it at the Choice selection reaction time in the purpose of this research and the possibility of the objective evaluation is examined from the surface electromyogram and the electrocardiogram.We Have the highway for two hours to travel the subject choice reaction time was measured before and after practice running.Electromyogram measure using lower extremity muscular group for pedal operating analysis, included tibialis anterior and Gastrocnemius medialis.As a result,it has been understood to delay greatly at a problem yellow (LED) at the reflex time. The muscle fatigue was able to be extracted by the total electrical discharge amount analysis of the surface electromyogram. The decrease at awake the level was able to be extracted in LF/HF of the electrocardiogram.

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