• Title/Summary/Keyword: tendon slack length

Search Result 5, Processing Time 0.024 seconds

Estimation of Muscle-tendon Model Parameters Based on a Numeric Optimization (최적화기법에 의한 근육-건 모델 파라미터들의 추정)

  • Nam, Yoon-Su
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.26 no.6
    • /
    • pp.122-130
    • /
    • 2009
  • The analysis of human movement requires the knowledge of the Hill type muscle parameters, the muscle-tendon and moment arm length change as a function of joint angles. However, values of a subject's muscle parameters are very difficult to identify. It turns out from a sensitivity analysis that the tendon slack length and maximum muscle force are the two critical parameters among the Hill-type muscle model. Therefore, it could be claimed that the variation of the tendon slack length and maximum muscle force from the Delp's reference data will change the muscle characteristics of a subject remarkably. A numeric optimization method to search these tendon parameters specific to a subject is proposed, and the accuracy of the developed algorithm is evaluated through a numerical simulation.

Development of a Model for the Estimation of Knee Joint Moment at MVC (MVC 상태에서의 무릎관절 모멘트 추정을 위한 모델 개발)

  • Nam, Yoon-Su;Lee, Woo-Eun
    • Journal of Biomedical Engineering Research
    • /
    • v.29 no.3
    • /
    • pp.222-230
    • /
    • 2008
  • This paper introduces a method of estimating the knee joint moment developed during MVC. By combining the Hill-type muscle model and analytic results on moment arm and musculotendon length change as a function of hip and knee joint angle, the knee joint moment at a specific knee joint angle during MVC is determined. Many differences between the estimated results and the experimental data are noted. It is believed that these differences originate from inaccurate information on the muscle-tendon parameters. The establishment of exact values for the subject's muscle parameters is almost impossible task. However, sensitivity analysis shows that the tendon slack length is the most critical parameter when applying the Hill-type muscle model. The effect of a change of this parameter on the muscle length force relationship is analyzed in detail.