The value of grip force is widely used for the brawn measurement in the physical strength examination because of its easy measurement. However, by use of the grip dynamometer being on the market, force is measured to only one direction, so it is doubtful whether various kinds of brawn can be measured. For example, the grip force to tennis racket seems to be different from the force measured by the grip dynamometer. Therefore, we developed the equipment to measure brawn gripping the cylindrical bject like tennis racket grip. Then we examined characteristics of both conven ional grip dynamometer and the newly developed equipment. As the result, for the ormer, grip width has an influence slightly on grip force, but, for the latter, grip iameter affects strongly as the human sense feels.

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Every skier who enjoys skiing probably wishes to master parallel turns(Christies)repeated rhythmically in a stable manner. To repeat parallel turns, the skier needs to transpose his weight from one side edge of ski to another when he starts next turning. Furthermore, at that instant, the value of edging angle of ski passes through zero .Therefore, in the course of repeated parallel turns, the skier must perform smooth turning between unstable states of zero edging angle. In the present investigation, we assume a stick-pictured model of skier of which the rigid upper body is combined with the rigid lower body at the hip joints. The skier is assumed to be equipped with a single rigid ski in which an effective side-curve is formed. We take into account only one degree of freedom of skier's internal motion, namely, the rotation of hip joints (the rotation of upper body around the femur axes), which simulates the mechanism of the Alpine ski-robot. We derive the equations of motion and solve them numerically. The skier starts turning by carving turn along the effective side-curve of ski and then the skidding of ski takes place by the centrifugal force. When the value of edging angle of ski decreases down to zero, the weight of skier is transposed to the another edge of ski and the next turning begins towards counter side. We obtained the results corresponding to repeated parallel turns with long as well as short rhythm. These results show essential features of repeated parallel turns performed by a human skier and suggest how to practice skillful parallel turns.

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The restitutional property is one of the most important factors on the regulation baseball bats. When balls collides with baseball bats, local deformations are caused on the attack surface. These local deformations have the great influence upon the restitutional properties. In this study, the relationship between the local deformations and restitutional properties is made clear by using the finite element method. In order to make the designing guide of baseball bats, the relationship between the local deformations and mechanical properties of the baseball bats such as flexural and lateral compressive stiffnesses is investigated. The application of fiber reinforced plastics (FRP) to regulation baseball bats is also examined. This application can give the more extensive approach to the designing of baseball bats, compared with conven tional materials such as wood and metals, because the FRP has the high specific stiffness and the anisotropy.

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Dynamics of Japanese bows is very complicated, so that computer simulations are seriously required to analyze the dynamics. In this paper, a link segment model was used to represent the restitution of Japanese bow and to calculate torque about grip position to shoot arrows horizontally. The model provided here could well reproduce two dimentional restitution of Japanese bow and trajectories of flying arrows . It is also found that downward torque about grip was necessary to maintain horizontal trajectories of arrows.

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Hard braking of a bicycle often causes ruler over the handlebar . To Analyse this phenomenon, we assumed that bicycle-rider system consist of rigid body model which have one mass and one arm. Input of this system was braking force function which acts as frictional force between tire and road surface . We analyzed this model by computer simulation method. Results of computer simulation well showed experiment tal data. Simulation showed, if rider braked very hard with him over the handlebar, he can avoid danger, as quickly as he could release brake levers, or as far as he couldshift his seated position backward.

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Two different bioenergetic power resources, anaerobic power and aerobic power, are supplied to human muscular exercise. In the field of exercise physiology, a great deal of experimental knowledge has been gathered, however, mathematical model of the power supply has not been determined. This paper describes the mathematical model of human bioenergetics and demonstrates some optimal running paces in long distance. On this study, the optimal control problem is to maximize the distance reached by 16.5 minute running. From the result of optimal solution, in the long distance running events, concentrated anaerobic power must be supplied at the last purt. As to compare with real running pace, this mathematical solution can be approximated to the real 5000 meter running event.

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The purpose of this study is to clarify the manufacturing and selling activities of Ozaki Ski Manufacturing in Fukui Prefecture from the end of the Taishow Era to the early years of Showa. The following conclusions were derived ;1) Ozaki of Ski Manufacturing began to manufacture skis in the autumn of the fourteenth year of Taishow Era.2) Skis, Sticks, Waxes were made from materials procured from all over, e.g. savings, metals, leather, bamboo.3) The business of the Ozaki Ski Manufacturing grew from local retail to all over the country.4) The manufacturing and selling activities of Ozaki Ski Manufacturing made rapid progress from the fifth year of the Showa Era. Ozaki Ski Manufacturing contributed to the spread of ski equipment all over the country.

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