Humphries B J, Newton R U, Wilson G J
Centre for Human Movement Science and Sports Management, University of New England, Northern Rivers, Australia.
Int J Sports Med. 1995 Feb;16(2):129-33. doi: 10.1055/s-2007-972979.
As a consequence of performing plyometric type exercises, such as depth jumps, impact forces placed on the musculoskeletal system during landing can lead to a potential for injury. A reduction of impact forces upon landing could therefore contribute to reduce the risk of injury. Twenty subjects performed a series of loaded jumps for maximal height, with and without a brake mechanism designed to reduce impact force during landing. The braked jumps were performed on the Plyometric Power System (PPS) with its braking mechanism set at 75% of body weight during the downward phase. The non-braked condition involved jumps with no braking. Vertical ground reaction force data, sampled for 5.5 s at 550 Hz from a Kistler forceplate, were collected for each jump condition. The following parameters were then calculated: peak vertical force, time to peak force, passive impact impulse and maximum concentric force. The brake served to significantly (p < 0.01) reduce peak impact force by 155% and passive impact impulse by 200%. No significant differences were found for peak concentric force production. The braking mechanism of the PPS significantly reduced ground impact forces without impeding concentric force production. The reduction in eccentric loading, using the braking mechanism, may reduce the incidence of injury associated with landings from high intensity plyometric exercises.
由于进行诸如跳深之类的增强式训练，着陆期间施加于肌肉骨骼系统的冲击力可能会导致受伤风险。因此，降低着陆时的冲击力有助于降低受伤风险。20名受试者进行了一系列负重跳跃以达到最大高度，分别在有和没有旨在降低着陆冲击力的制动机制的情况下进行。制动跳跃在增强式动力系统（PPS）上进行，其制动机制在下降阶段设置为体重的75%。无制动条件下的跳跃则没有制动。从奇石乐测力板以550Hz的频率采集5.5秒的垂直地面反作用力数据，针对每种跳跃条件进行收集。然后计算以下参数：垂直力峰值、达到峰值力的时间、被动冲击冲量和最大向心力量。该制动装置显著（p<0.01）将峰值冲击力降低了155%，将被动冲击冲量降低了200%。在最大向心力量产生方面未发现显著差异。PPS的制动机制显著降低了地面冲击力，同时不妨碍向心力量的产生。使用制动机制减少离心负荷，可能会降低与高强度增强式训练着陆相关的受伤发生率。
