This study aimed to investigate the influence of control of inspiratory-expiratory (I:E) ratio on coordination between locomotor and respiratory rhythms. Exercises of 10 healthy women were performed at the intensity corresponding to ventilatory threshold. Breathing rhythms were spontaneous breathing and two control breathings which I:E ratios were 1:1 and 1:2. The degree of coordination at I:E ratio of 1:1 was significantly higher than that of other breathing rhythms. Compared with spontaneous breathing, RPE was significantly lower at I:E ratio of 1:1 and significantly higher at I:E ratio of 1:2. V^^・E/V^^・O_2 at I:E ratio of 1:2 was significantly higher than that of I:E ratio of 1:1. The results suggest that control of breathing rhythm affect RPE, and control I:E ratio of 1:1 might be effective for coordination during walking at moderate intensity.

View full abstract

The purpose of this study was to examine the gait patterns of young and elderly people. The subjects were fifteen young males (mean age ±1SD; 19.6±1.9) and 4 elderly males (68.8±4.1). "Step widths" were configured in 3 types. The marker of the right shoulder and the center between the left and right shoulders were analyzed for the migration of the length generated by wobbling of the body trunk from right to left, which we termed the sideways "rolling index." Additionally we corrected the marker of data by an axis line. The center between the right and left shoulders formed a rolling index for "from right to left" on the 40cm step width, which was larger for the younger group than for the elderly group (F_<(1,51)>=3.45, p<0.1). As a result, the mark of right shoulder moved sideways as the step widths grow wider. Remarkably, the older group on the 20cm and 40cm step width had a larger rolling index for the left side than the right side (p<0.1, p<0.05). The rolling index of the elderly people decreased when the step widths widened. Also the elderly group expressed larger disproportionate shakiness on the left side than the younger group. We suggest that the stability of walking can be used as a useful single indicator for the risk of falling accidents.

View full abstract

To clarify the characteristics of Uzukuri, a straw brush for polishing a wood surface to make it uneven, through the sense of touch by the foot. Fifty subjects (31.6±12.5yrs, means±SD) touched 6 types flooring materials at invisible situation, and evaluated the sense of touch. Uzukuri polished cedar board, smooth cedar and carpet revealed similar data. Uzukuri Masame was the most popular material. Uzukuri has moderate stimulus and retains the characteristics of natural material. So, Uzukuri polished cedar is suitable for floor material.

View full abstract

Joint torque in humans is affected by such factors as optimum muscle and moment arm length. The torque exerted varies with the static joint angle, and the differences are generally called joint angle-torque characteristics, which vary with the type of joint and direction of joint motion. These characteristics are therefore regarded as important factors when considering the most appropriate postures for specific exertion in clinical practice or the biomechanical field. Several studies on angle-torque characteristics have been performed on a small number of subjects, but limited data has been obtained from studies performed on large number of subjects, let alone the assessment of the impact of such characteristics on the differences in the joint angle of extremity joints. Accordingly, in the present study, we investigated angle-torque characteristics of extremity joints based on the patient characteristic data of 711 healthy Japanese individuals obtained between 2001 and 2002 obtained from the National Institute of Technology and Evaluation. The results revealed characteristic peaks in the joint-torque curves near the center of the measurement range for elbow flexion, shoulder flexion, shoulder extension, and knee extension. The peaks were most evident in elbow flexion. The joint torque values in elbow extension, knee flexion, hip flexion, and extension characteristically peaked at either end of the measurement range. In addition, the results of a two-way ANOVA performed on joint torque with generation and joint angle as independent factors revealed that the joint torque was affected by generational differences. This result suggests that it is impossible to achieve adequate accuracy in the fields where joint angle-torque characteristics are used such as product design without the data for generational differences.

View full abstract