The purpose of this study is to develop a motor evaluation system for the lower limb using a sensor ergometer and a musculoskeletal model with the prospect that the system is used in rehabilitation and in general exercise institutions. To estimate joint angles from the pedal position, an inverse kinematics model was constructed, and the validity was investigated by comparing these values with those from a motion capture system. The muscle forces were calculated from the musculoskeletal model, and also compared with the filtered EMG patterns. Using the developed system, the effect of changing the saddle height on a mechanical load of the patellofemoral joint was discussed. As the results, the estimated joint angles agreed with those from the motion capture system with the accuracy of correlation coefficients of over 0.98, and the calculated muscle forces pointed to a trend to analogize with the EMG patterns. These results showed that the proposed system was valid. However, the relationship between the mechanical load of the patellofemoral joint and the saddle height was not found.

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We carried out fundamental experiments to investigate how people could adapt to such peculiar environment and develop their ability to adapt to it. We set up the constraint of experiments as “the peculiar environment” which made delayed response to their own reaction. Recently accidents for human error have occurred frequently in such peculiar environment. It may be considered that no elimination of such accidents partly owes to only insufficient researches on human behavior in such peculiar situation. We carried out two experiments through reduction to simple conditions in which response delay occurs. The results showed that people can acquire the ability to adapt to any environment of conditions in mixed response-delay environment. In addition, there was often acquisition of ability to adapt to little or no response delaying environment. People could not or little acquire it through accumulation of much response to larger delaying environment.

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Users viewing movies on LCDs often complain of blurring and bleeding of the images. Optically compensated bend (OCB) mode LCD panels are newly developed displays that have excellent moving picture quality. We measured the centre of gravity of subjects' bodies, and compared statokinesigrams obtained from subjects viewing moving maps on OCBs and on conventional model displays. The map of a fictitious city scrolled from left to right. The subjects first stood with their eyes open for 30 seconds; they then viewed each display in a moving map task for the following 30 seconds. The subjects were 55 people from 20 to 73 years of age, with no history of equilibrium function problems. We calculated two indices from statokinesigrams. Significant differences were observed between the displays in the indices. It was also shown that viewers' centre of gravity was steadier with OCBs than with conventional model displays. This trend was significant in younger people and but was less so with age.

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In this paper, we carried out a fundamental experiment to skill acquisition based on human factors. In recent years, many devices equipped with the interface that values the usability are developed. However, most of researches have addressed usability with specific hardware and software without sufficient investigation on human fundamental cognitive ability. We carried out an experiment on the effect of RRI (Response-Response Interval) on skill acquisition through reduction to simple conditions. Our results showed that people can produce higher frequency of correct responses and larger improvement over trials without RRI than with it. We found that the level of accuracy and improvement decreased as an inverse function of RRI.

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The recommendable diameter of vertical handrails and straps under vibration of trains was studied. Seventy-nine subjects were divided into 2 groups, “Adult” who were 59 years old or less and “elder” who were 60 years old or more. 5 levels of diameter, 3 kinds of antislip surface of handrail and 6 levels of strap diameter were tested. The recommendable diameter of handrails was around 28mm to 38mm for stainless, and the diameter of 40mm was also usable for antislip surfaces. These values were not changed according to age groups, but changed according to passengers' hand size. The recommendable diameter for strap was smaller than that of handrails, around 18mm to 29mm, and 25mm was the best diameter.

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