Mancinelli Chiara, Patritti Benjamin L, Tropea Peppino, Greenwald Richard M, Casler Rick, Herr Hugh, Bonato Paolo
Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital,Boston, MA 02114, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:8255-8. doi: 10.1109/IEMBS.2011.6092035.
Passive-elastic foot prostheses cannot produce net work. Consequently, passive-elastic foot prostheses are limited in their ability to enable a biologically-realistic gait pattern in transtibial amputees. This shortcoming results in difficulties in balance and walking and leads to high levels of oxygen consumption during locomotion. A powered prosthesis has the potential for overcoming these problems and allowing transtibial amputees to achieve a biologically-realistic gait pattern. In this study, we compared the effects of the Ceterus by Össur, a traditional passive-elastic prosthesis, with those of the PowerFoot Biom (iWalk, Cambridge, MA), a recently-developed powered prosthesis. Gait biomechanics and metabolic cost were compared in a group of 5 transtibial amputees during level-ground walking. The results provided preliminary evidence that the use of a powered prosthesis leads to a decrease in the level of oxygen consumption during ambulation due to improvements in ankle kinematics and kinetics primarily during late stance. An average decrease in oxygen consumption of 8.4% was observed during the study when subjects used the PowerFoot compared to the Ceterus. An average increase of 54% was observed in the peak ankle power generation during late stance. Our results suggest that powered prostheses have the potential for significantly improving ambulation in transtibial amputees.
被动弹性足部假肢无法产生净功。因此，被动弹性足部假肢在使胫骨截肢者实现生物逼真步态模式的能力方面受到限制。这一缺点导致平衡和行走困难，并在运动过程中导致高水平的氧气消耗。动力假肢有潜力克服这些问题，并使胫骨截肢者实现生物逼真的步态模式。在本研究中，我们比较了传统被动弹性假肢Össur的Ceterus与最近开发的动力假肢PowerFoot Biom（iWalk，马萨诸塞州剑桥）的效果。在一组5名胫骨截肢者进行平地行走时，比较了步态生物力学和代谢成本。结果提供了初步证据，表明使用动力假肢可使行走过程中的氧气消耗水平降低，这主要是由于在站立后期踝关节运动学和动力学的改善。与使用Ceterus相比，受试者使用PowerFoot时，在研究期间观察到氧气消耗平均降低了8.4%。在站立后期，踝关节峰值功率产生平均增加了54%。我们的结果表明，动力假肢有潜力显著改善胫骨截肢者的行走能力。
