Journal of the Society of Biomechanisms
Print ISSN : 0285-0885
Search
Advanced search
OR
Browse
Search
Volume 35, Issue 3
Displaying 1-10 of 10 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Reviews
Papers
  • Calculation of the bone mineral density of and stress on bone around
    Rina SAKAI, Takeaki YAMAMOTO, Yuichiro KURAKAGI, Katsufumi UCHIYAMA, N ...
    2011 Volume 35 Issue 3 Pages 191-196
    Published: 2011
    Released on J-STAGE: April 15, 2016
    DOIhttps://doi.org/10.3951/sobim.35.191
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In cementless stem fixation, BMD reduction around the stem is of concern because it may cause loosening. This BMD reduction is assumed to be caused by stem implantation-induced alteration of the physiological feedback system, which may cause stress shielding and result in loosening, but the causal relationship has not been clarified. In this study, using a Duetto SI stem, we investigated the correlation between the postoperative BMD around the stem and stress. In patients who underwent their first THA at the orthopedic department of our university, the BMD was measured using DEXA, and FEA was performed with an equivalent time-course. Time-course changes in the BMD, von Mises stress, and triaxial stress in Gruen zones 1 through 7 were calculated from those measured at 2 weeks and 5 months after surgery. The BMD and von Mises stress showed a bidirectional correlation in case that horizontal axis was Gruen zones. An increase in stress loaded on bone was assumed to be a factor elevating the BMD. The Duetto SI stem was fixed on the distal side, suggesting its stable fixation. BMD measurement and FEA were useful for quantification of the bone dynamics around the stem from an early phase.
    View full abstract
    Download PDF (1180K)
  • Adequacy of physical activity time evaluated by a triaxial accelerometer
    Taku Sato, Natsuki Kitamura, Atsuyoshi Kawagoshi, Shunichi Sakata, Nor ...
    2011 Volume 35 Issue 3 Pages 197-200
    Published: 2011
    Released on J-STAGE: April 15, 2016
    DOIhttps://doi.org/10.3951/sobim.35.197
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Aim: The purpose of this study was to examine the validity of physical activity by a triaxial accelerometer which was developed in Japan recently. Subjects and Method :Ten healthy young students were studied in this study. They wore a triaxial accelerometer during their daily activities, and their physical activities (lying, sitting, standing, and walking) were videotaped. We examined relationships between the time measured with a triaxial accelerometer and that measured with video camera, and also analyzed the errors between the two measurements by Bland-Altman analysis. Results: The relevance between the two measurements showed a very strong correlation in all measurements. There were no additional errors among supine, standing, and walking but there was additional error in sitting position. There were no proportional errors in all four positions. Conclusion: The validity of physical activity measured by a triaxial accelerometer newly developed was suggested in this study.
    View full abstract
    Download PDF (1025K)
  • The Effects of Stair Dimensions on Movements during Climbing Up and
    Tomoaki Mori, Masako Yoshimura, Yasushi Sugano, Satoshi Muraki
    2011 Volume 35 Issue 3 Pages 201-207
    Published: 2011
    Released on J-STAGE: April 15, 2016
    DOIhttps://doi.org/10.3951/sobim.35.201
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A stairway in homes is an important structure for movement between floors. However, the number of fall accidents on stairways is very high in Japan. The present study aimed at investigating the dimensions of safe stairways especially by subjective assessments and three-dimensional motion in both sexes and three age’s groups. Eighteen healthy men and women aged between 21 and 75 years climbed up and down five kinds of stairs at different dimensions (rise and tread of a step). While going up the stairs, the height of a step influenced the track movement of their toes, which decreased distances between the toes and edge of the stairs, especially in the elderly group. Furthermore, the female group trended to feel more subjective strain with a larger height of a step. While going down stairs, a smaller tread of a step decreased the contact area of the soles on the surface of the step. These findings suggest that requirements of stair’s dimensions for preventing fall are different for climbing up and down, and for users of different ages and sex.
    View full abstract
    Download PDF (1298K)
Series
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top