South Brian J, Fey Nicholas P, Bosker Gordon, Neptune Richard R
Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
J Biomech Eng. 2010 Jan;132(1):015001. doi: 10.1115/1.4000166.
Proper selection of prosthetic foot-ankle components with appropriate design characteristics is critical for successful amputee rehabilitation. Elastic energy storage and return (ESAR) feet have been developed in an effort to improve amputee gait. However, the clinical efficacy of ESAR feet has been inconsistent, which could be due to inappropriate stiffness levels prescribed for a given amputee. Although a number of studies have analyzed the effect of ESAR feet on gait performance, the relationships between the stiffness characteristics and gait performance are not well understood. A challenge to understanding these relationships is the inability of current manufacturing techniques to easily generate feet with varying stiffness levels. The objective of this study was to develop a rapid prototyping framework using selective laser sintering (SLS) for the creation of prosthetic feet that can be used as a means to quantify the influence of varying foot stiffness on transtibial amputee walking. The framework successfully duplicated the stiffness characteristics of a commercial carbon fiber ESAR foot. The feet were mechanically tested and an experimental case study was performed to verify that the locomotor characteristics of the amputee's gait were the same when walking with the carbon fiber ESAR and SLS designs. Three-dimensional ground reaction force, kinematic, and kinetic quantities were measured while the subject walked at 1.2 m/s. The SLS foot was able to replicate the mechanical loading response and locomotor patterns of the ESAR foot within +/-2 standard deviations. This validated the current framework as a means to fabricate SLS-based ESAR prosthetic feet. Future work will be directed at creating feet with a range of stiffness levels to investigate appropriate prescription criteria.
正确选择具有适当设计特征的假肢足踝组件对于截肢者的成功康复至关重要。为了改善截肢者的步态，人们开发了弹性储能与回能（ESAR）足。然而，ESAR足的临床疗效并不一致，这可能是由于为特定截肢者规定的刚度水平不合适。尽管许多研究分析了ESAR足对步态性能的影响，但刚度特征与步态性能之间的关系尚未得到很好的理解。理解这些关系的一个挑战是当前制造技术无法轻松制造出具有不同刚度水平的足部。本研究的目的是开发一种使用选择性激光烧结（SLS）的快速成型框架，用于制造假肢足，作为量化不同足部刚度对胫部截肢者行走影响的一种手段。该框架成功复制了商用碳纤维ESAR足的刚度特征。对这些足部进行了力学测试，并进行了一个实验案例研究，以验证截肢者在使用碳纤维ESAR足和SLS设计行走时步态的运动特征是否相同。当受试者以1.2 m/s的速度行走时，测量了三维地面反作用力、运动学和动力学量。SLS足能够在±2个标准差范围内复制ESAR足的机械载荷响应和运动模式。这验证了当前框架作为制造基于SLS的ESAR假肢足的一种手段。未来的工作将致力于制造具有一系列刚度水平的足部，以研究合适的处方标准。
