Ski vibration and EMG（Elecromyography）measurement have been important in the evaluation of a ski performance or the investigation of a ski injury or exhaustion in skiing. The purpose of this study was to develop a new date logger system for parallel measurements of ski vibration as a physical element and EMG as a physiological element. Until now, vibration and EMG could not be measured in parallel using one unit, because the natural frequency of the vibration was different from that of the EMG. In the system, both can be measured electrically over time, in parallel. This allows integration of physical and physiological data for the study of such situations as occur in actual skiing. Furthermore, these data are transformed into a power spectrum by fast furrier transformation to calculate the MPF（mean power frequency）for the index of exhaustion. In test results, integrated EMG, EMG and vibration frequency components can be shown over time in skiing in parallel. In addition, an analysis on interactive relationship between the vibration of ski and the EMG were performed using this system.

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We have developed various kinds of the alpine skiing robot to clarifying the basic elements of a skier's movements, which look complex during turns. The skiing turn is classified roughly into carving turns and skidding turns. The alpine skiing robot is split into two basic types: an active type（with actuator）and a passive type （without actuator）．We have developed active carving-turn models with actuators, skidding-turn models with actuators, and passive carving-turn models without actuators. However, so far the research has not included the conditions and objectives of a passive skidding-turn model without an actuator. So we have developed a passive skidding-turn model, with inner rotation of the hip joints around the femur axes, but with no actuation, and which can snowplow like a skier. In terms of the performance of the passive skidding-turn model, keeping the bilateral hip joints of the skidding-turn model（which are rotated slightly inside with a trapezoidal double-lever mechanism of the four links of a quadric crank-chain），a sequential skidding-turn could be achieved with energy- less skiing. For the passive skidding-turn model, even if the rudder angle was applied to the top-lifted side, a turn could be achieved. Moreover, the direction of the turns of the skidding-turn model with inner rotation of the hip joints corresponded overall to the direction of the steer of a ship.

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This paper deals with the motion analysis of ski turns and the 3D posture measurement of skier in gliding on the actual snow field. The measurement system consists of the inertial sensor（the 3-axis gyro sensor and the 3-axis acceleration sensor）and measures the 3-axis angular velocity and the 3-axis acceleration. We established the motion measurement method that estimates the 3D posture（Roll-Pitch-Yaw angles）in local coordinate system using the inertial sensor output. This method can compensate the drift error of gyro sensor output and avoid the effect of dynamic acceleration by applying the Unscented Kalman filter. Therefore, the method can be used to measure the motion of skier gliding on the actual snow field at high speed. We conducted the measurement experiment of carving and skidding turns by the skier gliding on the actual snow field. The measurement systems were attached to the body segments（upper body, lumber, upper thighs and lower thighs）of skier and the ski boots. The joint angles（lumber, hips, knees and ankles）of skier were calculated by applying the 3D posture to the inverse kinematics. The results of measurement experiment indicated quantitatively the joint angles of skier, and the analysis results represented the major features of skier in carving and skidding turns.

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This paper deals with the estimation of lower limb muscle tension and the motion analysis of skier gliding on the actual snow field. The lower limb muscle tension is estimated by the measurement information of motion and reaction force from snow surface. The motion measurement system that consists of the gyro sensor, the acceleration sensor and the magnetic field sensor measures the 3-axis angular velocity, the 3-axis acceleration and the 3-axis magnetic field. The measurement system of reaction force from snow surface that consists of the 6-axis force sensor measures 3-axis force and 3-axis moment vectors from snow surface. The joint angles and joint torques are calculated using the sensor fusion, the inverse kinematics and the inverse dynamics. The lower limb muscle tension is estimated by applying the joint angle, the joint torque and the body segment parameter to the 3D muscle-skeleton model. The measurement experiment was conducted for the skier gliding on the actual snow field. The motion measurement systems were attached to body segments（lumber, upper thighs and lower thighs）of skier and ski boots. The measurement systems of reaction force were installed to between boots and skis. The results of the motion analysis by the lower limb muscle tension indicated the major muscle activities of the skier gliding on the actual snow field. Therefore, the motion analysis method can be used to development of training and injury prevention methods.

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Sapporo was selected as the host of the Winter Olympic Games by the I.O.C. in 1937. However, due to the outbreak of the second Sino-Japanese war, it did not happen, so it was called the Visionary Winter Olympic Games. The objective of this study is to indicate the activities for improvement and use of performance enhancement approaches in skiing that the National Ski Association of Japan had prepared for the Winter Olympic Games. The National Ski Association of Japan facilitated performance enhancement in order to match to the top level skiing standards of the world from1928 to1931. This involved the invitation of top Norwegian ski racers and the introduction of new ski race events throughout Japan. In 1932 the National Ski Association of Japan designed and rapidly implemented a special program to attain medals for the upcoming 1932 Winter Olympic Games. They carried out various programs from 1932 to 1935. The contents of these programs consisted of fostering good ski racers, building a strong skiing establishment and practicing the best plan to win. The result was successful, in that the National Ski Association of Japan achieved better results than the previous Winter Olympic Games.

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Alpine skiers require both aerobic and anaerobic capacity particularly for knee extension and flexion muscle strength. As for most all athletes, lactic acid removal is of utmost importance. In past studies, athletes from various disciplines have had their anaerobic power test measured using the power max VⅡ, but these studies were limited to only three parameters: body weight per peak power（watt/kg）；peak revolution（rpm）；and peak weight load（kp）．However, the data generated was not very useful for elucidating discipline specific characteristics. With that in mind, we felt it necessary to search for more meaningful parameters that could possibly distinguish between speed and strength type muscle power and their relative contributions for peak performance in a range of disciplines. We studied such parameters in alpine skiers and found that they do indeed provide extremely useful data that can be used to better fine tune their training regimen. This study consisted of 97 subjects in three categories: ALP; 32 alpine skiers, XC; 39 cross-country skiers, and a control group of 28 fit but not athletically competitive adults. The average max power outputs for each group were as follows: ALP group 14.8±1.5watt, XC group 13.9±1.4watt, CONT group 13.1±1.5; anoxia values for the power tests anoxia characteristics are not shown as the results are obvious（ALP＞XC＞CONT）． The observed strength to speed ratios varied significantly among the three groups: ALP＞XC＞CONT, with only the CONT ratio being below 1. This suggests that for alpine skiers the best training regimen should focus heavily on developing power in strength type muscles.

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In Japan, the number of telemark skiers has increased in recent years. However, most of them use alpine skis instead of specialized telemark ones. Although alpine skis are heavier than telemark skis, they are more controllable when skiing downhill and are preferred when skiing downhill compared to hiking uphill or walking around a snow mountain.
Traditionally, telemark bindings are attached to a ski according to its code-center, which is the middle of a ski length. The code-center has to be matched with a three-pin-line located under a skier’s telemark boot. Certain alpine skis, however, do not suit telemark skiing, particularly if telemark bindings are traditionally mounted. This is because alpine skis are specifically designed for alpine skiing and not for telemark skiing. However, these skis also have a boot-center line generally marked by a ski manufacturer. This line can be used to set up bindings for alpine skiing.
It is useful to know the most efficient mounting point of telemark bindings on alpine skis. This study conducted tests with two different settings of telemark bindings. In the first setting, the adopted boot-center line was used, which was in a position similar to that of the code-center. In the other set up the telemark bindings were positioned 5 cm forward from the first position. A tester skied in hard snow as well as mixed snow conditions with the two settings to examine the skis’ operability. From the results, this study considered an alternative method to set up the telemark bindings that would provide skiers with better operability.
The results of this test suggest that the second setting, in which the binding position was approximately 5 cm forward from the traditional setting, allowed better ski control.

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