Department of Veterans Affairs, Rehabilitation Research and Development Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, VA Puget Sound, 1660 S Columbian Way, Seattle, WA 98108, USA.
J Biomech. 2011 Jun 3;44(9):1673-7. doi: 10.1016/j.jbiomech.2011.03.028. Epub 2011 Apr 8.
Non-articulated energy storage and return prosthetic feet lack any true articulation or obvious point of rotation. This makes it difficult to select a joint center about which to estimate their kinetics. Despite this absence of any clear point of rotation, methods for estimating the kinetic performance of this class of prosthetic feet typically assume that they possess a fixed center of rotation and that its location is well approximated by the position of the contralateral lateral malleolus. To evaluate the validity of this assumption we used a finite helical axis approach to determine the position of the center of rotation in the sagittal plane for a series of non-articulated energy storage and return prosthetic feet. We found that over the course of stance phase, the sagittal finite helical axis position diverged markedly from the typically assumed fixed axis location. These results suggest that researchers may need to review center of rotation assumptions when assessing prosthetic foot kinetics, while clinicians may need to reconsider the criteria by which they prescribe these prosthetic feet.
非关节储能和回传假肢脚缺乏任何真正的关节或明显的旋转点。这使得很难选择一个关节中心来估计它们的动力学。尽管没有明显的旋转点，但估计这类假肢脚的动力学性能的方法通常假设它们具有固定的旋转中心，并且其位置可以通过对侧外踝的位置很好地近似。为了评估这一假设的有效性，我们使用有限螺旋轴方法来确定一系列非关节储能和回传假肢脚在矢状面内的旋转中心位置。我们发现，在整个站立阶段，矢状有限螺旋轴的位置与通常假设的固定轴位置明显不同。这些结果表明，研究人员在评估假肢脚动力学时可能需要重新审视旋转中心的假设，而临床医生可能需要重新考虑他们为这些假肢脚开处方的标准。
