Department of Pathophysiology and Transplantation, University of Milan, Milano, Italy.
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Scand J Med Sci Sports. 2019 Dec;29(12):1892-1900. doi: 10.1111/sms.13520. Epub 2019 Aug 18.
Sprint running is a common feature of many sport activities. The ability of an athlete to cover a distance in the shortest time relies on his/her power production. The aim of this study was to provide an exhaustive description of the mechanical determinants of power output in sprint running acceleration and to check whether a predictive equation for internal power designed for steady locomotion is applicable to sprint running acceleration. Eighteen subjects performed two 20 m sprints in a gym. A 35-camera motion capture system recorded the 3D motion of the body segments and the body center of mass (BCoM) trajectory was computed. The mechanical power to accelerate and rise BCoM (external power, P ) and to accelerate the segments with respect to BCoM (internal power, P ) was calculated. In a 20 m sprint, the power to accelerate the body forward accounts for 50% of total power; P accounts for 41% and the power to rise BCoM accounts for 9% of total power. All the components of total mechanical power increase linearly with mean sprint velocity. A published equation for P prediction in steady locomotion has been adapted (the compound factor q accounting for the limbs' inertia decreases as a function of the distance within the sprint, differently from steady locomotion) and is still able to predict experimental P in a 20 m sprint with a bias of 0.70 ± 0.93 W kg . This equation can be used to include P also in other methods that estimate external horizontal power only.
冲刺跑是许多运动项目的共同特征。运动员在最短时间内覆盖距离的能力取决于他/她的力量产生能力。本研究的目的是提供一个详尽的描述在短跑加速中机械决定力量输出的说明，并检查一个为稳定运动设计的内部功率预测方程是否适用于短跑加速。18 名受试者在健身房进行了两次 20 米短跑。一个 35 个摄像机的运动捕捉系统记录了身体部位的三维运动，计算了身体质心（BCoM）的轨迹。加速和提升 BCoM 的机械功率（外部功率，P）和相对于 BCoM 加速身体部位的功率（内部功率，P）。在 20 米的短跑中，加速身体向前的力量占总功率的 50%；P 占 41%，提升 BCoM 的力量占总功率的 9%。总机械功率的所有组成部分都随平均冲刺速度线性增加。一个用于预测稳态运动中 P 的方程已经被改编（与稳态运动不同，代表肢体惯性的复合因子 q 随着短跑距离的变化而减小），并且仍然能够以 0.70±0.93 W kg 的偏差预测 20 米短跑中的实验 P。这个方程可以用于其他只估计外部水平力量的方法中，也包括 P。
