This paper describes the effectiveness of armrests from the lower limb moment during the standing-up motion. Armrests are an important element in the standing-up motion from a chair in our daily life. To clarify the usability and the effectiveness of armrests is our purpose in this study. Chairs with/without armrests were examined in two ways as follows. Firstly, it was measured the locus of C. G. (center of gravity), velocities of the C. G., and the joint angles of subjects by using the image analysis. Secondly, it was calculated the lower limb moments (ankle, knee, hip) combining the motion analysis and the measured floor reaction forces. The result from the image analysis showed, it was clear that chairs with armrests make the amount of body flexion decrease during the standing-up motion. In addition to this result, the hip moment also decreased. Finally, it was found also that the knee moment decreases for chairs with armrests compared with chairs without armrests.

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This paper describes the results of experiments made on the most adequate supports of commuter trains under vibratory condition using train simulator. The lengths of straps were divided into 275mm, 375mm and 475mm; the heights of straps were ranged from 80 to 120% in terms of the ratio to the height of passengers with shoes. With respect to the strap length of 275mm, a ratio of 99% to the height of a passenger is the best, while the ratios between 90% and 105% were assessed to be an allowable range. Where straps became longer, the allowable range was limited by a decrease in the evaluation under lower conditions. Some recommendable patterns of strap height and length were found out in view of minimizing the ratio of passengers who are out of allowable range. The distance between handrails and seats were varied into five levels from 0 to 250mm. The handrails 150mm apart from the seats were more readily usable to compare with existent handrails as spaced nil from the seats; the flow of passengers was not disturbed.

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Force applied to wheels and handgrips of a four-wheeled walker during steady walking has been investigated by an experiment using force plates and by a theoretical model of the walker. In order to verify the validity of the theoretical model for the walker, ten healthy male subjects participated in the experiment. Each subject walked using three kinds of walkers. Force applied to the wheels was measured by two force plates. The theoretical model estimated the force and the torque applied to the handgrips and the wheels from the equilibrium of the force and the moment in the saggital and the frontal planes. Force applied to the front and the rear wheels depends on the center of gravity of the walker. To stabilize the body posture during a single supporting period, the user pushes the handgrips laterally toward the unsupported side. As a result, larger force is applied to the unsupported-side wheels in comparison to the supported-side wheels. The position of the basket of the walker should be designed from an ergonomic point of view because inequality of force applied to the front and the rear wheels can occur.

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