Mandic Radivoj, Jakovljevic Sasa, Jaric Slobodan
University of Belgrade, Faculty of Sport and Physical Education, The Research Center, Blagoja Parovica 156, Belgrade, Serbia.
University of Delaware, Department of Kinesiology and Applied Physiology, Rust Arena, Rm. 143, 541 South College Avenue, Newark 19716, DE, USA; University of Delaware, Biomechanics and Movement Science Graduate Program, Rust Arena, Rm. 143, 541 South College Avenue, Newark 19716, DE, USA.
J Electromyogr Kinesiol. 2015 Apr;25(2):265-72. doi: 10.1016/j.jelekin.2014.11.001. Epub 2014 Nov 13.
Although maximum height (H(max)), muscle force (F), and power output (P), have been routinely obtained from maximum vertical jumps for various purposes, a possible role of the countermovement depth (H(cmd)) on the same variables remains largely unexplored. Here we hypothesized that (1) the optimum H(cmd) for maximizing H(max) exists, while (2) an increase in H(cmd) would be associated with a decrease in both F and P. Professional male basketball players (N=11) preformed maximum countermovement jumps with and without arm swing while varying H(cmd)±25 cm from its preferred value. Although regression models revealed a presence of optimum H(cmd) for maximizing H(max), H(max) revealed only small changes within a wide range of H(cmd). The preferred H(cmd) was markedly below its optimum value (p < .05). However, both F and P sharply decreased with H(cmd), while F also revealed a minimum for H(cmd) close to its highest values. Therefore, we conclude that although the optimum H(cmd) should exists, the magnitude of its effect on H(max) should be only minimal within a typical H(cmd) range. Conversely, F and P of leg muscles assessed through maximum vertical jumps should be taken with caution since both of them could be markedly confounded by H(cmd).
尽管出于各种目的，人们经常从最大垂直跳跃中获取最大高度（H(max)）、肌肉力量（F）和功率输出（P），但反向运动深度（H(cmd)）对这些相同变量的潜在作用在很大程度上仍未得到探索。在此，我们假设：（1）存在使H(max)最大化的最佳H(cmd)，同时（2）H(cmd)的增加将与F和P的降低相关。11名职业男性篮球运动员在有和没有摆臂的情况下进行最大反向运动跳跃，同时将H(cmd)在其偏好值的基础上上下变动25厘米。尽管回归模型显示存在使H(max)最大化的最佳H(cmd)，但在较宽的H(cmd)范围内，H(max)仅显示出微小变化。偏好的H(cmd)明显低于其最佳值（p < 0.05）。然而，F和P均随H(cmd)急剧下降，同时F在接近其最高值的H(cmd)处也显示出最小值。因此，我们得出结论，尽管最佳H(cmd)应该存在，但其对H(max)的影响程度在典型的H(cmd)范围内应该很小。相反，通过最大垂直跳跃评估的腿部肌肉的F和P应谨慎对待，因为它们都可能受到H(cmd)的显著混淆。
