Department of Kinesiology, California State University, Sacramento, California, United States of America.
The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
PLoS One. 2020 Feb 20;15(2):e0229035. doi: 10.1371/journal.pone.0229035. eCollection 2020.
Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kN·m-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.
跑步专用假肢（RSP）使双侧小腿截肢运动员能够参加奥运会比赛。然而，与生物腿相比，使用 RSP 的性能效果仍然存在争议。此外，不同的假肢配置，如形状、刚度和高度，可能会影响性能。我们确定了使用 15 种不同的 RSP 配置对 5 名双侧小腿截肢男性运动员最大速度的影响。这些运动员使用三种不同的 RSP 模型（Freedom Innovations Catapult FX6、Össur Flex-Foot Cheetah Xtend 和 Ottobock 1E90 Sprinter），每个模型都有五个刚度类别和高度的组合，进行了最大速度试验。我们在每次最大速度试验中测量地面反作用力，以确定与不同 RSP 配置和最大冲刺速度相关的生物力学参数。与使用 C 形 Catapult FX6 RSP 相比，使用 J 形 Cheetah Xtend 和 1E90 Sprinter RSP 可分别使最大速度提高 8.3%和 8.0%（p<0.001）。RSP 刚度既不以类别（p = 0.836）表示，也不以 kN·m-1（p = 0.916）表示，均不影响最大速度。此外，假肢高度对最大速度没有影响（p = 0.762）。最大速度与减少的地面接触时间、腾空时间和整体腿部刚度有关，与站立平均垂直地面反作用力、接触长度和垂直刚度更大有关（腾空时间 p = 0.015，所有其他变量 p<0.001）。RSP 的形状而不是刚度或高度，会影响双侧小腿截肢运动员的最大速度。
