Taboga Paolo, Grabowski Alena M, di Prampero Pietro Enrico, Kram Rodger
Department of Medical and Biological Sciences, University of Udine, Udine, Italy, and with the Integrative Physiology Department, University of Colorado Boulder, Boulder, CO.
J Appl Biomech. 2014 Jun;30(3):381-9. doi: 10.1123/jab.2013-0113. Epub 2013 Dec 17.
In the 2012 Paralympic 100 m and 200 m finals, 86% of athletes with a unilateral amputation placed their unaffected leg on the front starting block. Can this preference be explained biomechanically? We measured the biomechanical effects of starting block configuration for seven nonamputee sprinters and nine athletes with a unilateral amputation. Each subject performed six starts, alternating between their usual and unusual starting block configurations. When sprinters with an amputation placed their unaffected leg on the front block, they developed 6% greater mean resultant combined force compared with the opposite configuration (1.38 ± 0.06 vs 1.30 ± 0.11 BW, P = .015). However, because of a more vertical push angle, horizontal acceleration performance was equivalent between starting block configurations. We then used force data from each sprinter with an amputation to calculate the hypothetical starting mechanics for a virtual nonamputee (two unaffected legs) and a virtual bilateral amputee (two affected legs). Accelerations of virtual bilateral amputees were 15% slower compared with athletes with a unilateral amputation, which in turn were 11% slower than virtual nonamputees. Our biomechanical data do not explain the starting block configuration preference but they do explain the starting performance differences observed between nonamputee athletes and those with leg amputations.
在2012年残奥会100米和200米决赛中，86%的单侧截肢运动员将其未受影响的腿放在前面的起跑器上。这种偏好能用生物力学来解释吗？我们测量了7名非截肢短跑运动员和9名单侧截肢运动员起跑器配置的生物力学效应。每个受试者进行6次起跑，在其常用和不常用的起跑器配置之间交替。当截肢短跑运动员将其未受影响的腿放在前面的起跑器上时，与相反配置相比，他们产生的平均合力总和大6%（1.38±0.06与1.30±0.11体重，P = 0.015）。然而，由于推角更垂直，起跑器配置之间的水平加速性能相当。然后，我们使用每个截肢短跑运动员的力数据来计算虚拟非截肢者（两条未受影响的腿）和虚拟双侧截肢者（两条受影响的腿）的假设起跑力学。虚拟双侧截肢者的加速度比单侧截肢运动员慢15%，而单侧截肢运动员又比虚拟非截肢者慢11%。我们的生物力学数据无法解释起跑器配置偏好，但确实解释了非截肢运动员和腿部截肢运动员之间观察到的起跑性能差异。
