[in Japanese]

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[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

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The objective of this study is to experimentally validate the optimal walking form in water for muscle training, which was proposed in the previous study. The electromyogram and motion of the lower extremity, as well as the ground reaction force, were measured for five subjects walking in various forms. From the motion analysis, it was confirmed that the subjects walked in the same form as the simulation analysis in the previous study. It was also conformed that the difference between GRF of normal form and that of proposed forms was small. Finally, the validity of the proposed form was verified since the value of electromyogram of the proposed form was significantly larger than that of other forms.

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This paper proposes a method of estimating fingertip forces in finger tapping movements based on human fingerpad characteristics. In this method, first, the relationship between the fingertip force and the displacement, which are caused by elastic deformation between the thumb and index fingerpads, is modeled as a fingerpad-stiffness model. Then, using this model, the force between the two fingertips (the fingertip force) can be estimated from the measured fingerpad deformation only. In the experiments, fingertip forces and the displacements between the two fingerpads generated when a subject pinched and pushed a force sensor with the thumb and index finger were measured to approximate the relationships between fingerpad force and deformation. The results indicated that human fingerpad characteristics can be expressed using a nonlinear fingerpad-stiffness function, and that fingerpad forces can be estimated using the proposed model. Furthermore, finger tapping forces of Parkinson’s disease (PD) patients were compared with those of healthy subjects. These results lead us to conclude that the finger tapping forces could be used as a new index for evaluating the finger motor function.

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Simple goniometer for hip joint was developed utilizing universal joint. It uses two angular sensors and a displacement meter of the strain gauge-type. Accurate positioning is not necessary for the goniometer developed, which was the problem of conventional goniometer. Basing upon a mechanical model, the center of hip joint was estimated theoretically by the least-square method. The slide tracks on a femoral head were calculated. According to the results, characteristic patterns were obtained that reflected the way of walking of each subject.

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In cementless stem fixation, the strong hammering of the stem required to ensure sufficient fixation force is occasionally complicated by the occurrence of bone fracture. Because small bone fractures that are not visible to the unaided eye or through X-ray radiographs are not detected, however, the reported incidence of small bone fractures is currently underestimated. We determined the amount of stress applied on the femur during cementless stem press-fit fixation using stress measurements and finite element analyses. Employing the same method as that used in total hip arthroplasty, we hammered the stem into artificial femurs which were mechanically equivalent to living femurs. The hammer was attached to a load sensor which allowed us to compare the amount of stress applied on the osseous tissue. Using stress measurements and finite element analysis, we then evaluated the conditions under which bone fractures are likely to occur. Under these conditions, we found that the hammering force caused fracture of the artificial femur. Our measurements showed that the hammering force was more than 9.25 kN and von Mises stress generated by the first and second hammer strikes was 31 and 68 MPa, respectively. The first two hammer strikes caused large displacement, and were therefore unlikely to generate intraoperative fractures. Two strikes are sufficient to emplace stems requiring a large displacement.

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The purpose of this study is to investigate the characteristics of sprint motion in children through the comparison of sprinting movements between fast and slow groups, which were classified among 20 children based on their sprint time．The fast group showed high values in stride length and step frequency that determined the sprint speed．For the movements to raise step frequency of the fast group， it was suggested that the small changes in angles of the hip and knee joint shortened the time of a support phase．For the movement to raise stride length，the fast group showed the knee joint extension at foot contact and the enhancement of the hip joint angular velocity at take off (that be called large strides sprint)．On the other hand, this study showed that the sprint motions of the fast group did not always correspond to the characteristics of the adult sprinters．

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Recently, the underwear that corrects the figure and posture by regularly adding belt type pressure is sold. The conditioning product for the posture stabilization of the belt type that causes the effect for the whole body that is called the Posture-Stability-Sytem belt is sold in inter-reha co., Ltd. Reebok made new functionality wear based on the Posture-Stability-system belt. Gait Analysis when this product was worn was executed. After that the pelvis inclining forward is generated. And the trunk extension was generated

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