Spine Biomechanics Laboratories, Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
J Strength Cond Res. 2012 Jan;26(1):16-27. doi: 10.1519/JSC.0b013e31823a4063.
The intent of this study was to quantify spine loading during different kettlebell swings and carries. No previously published studies of tissue loads during kettlebell exercises could be found. Given the popularity of kettlebells, this study was designed to provide an insight into the resulting joint loads. Seven male subjects participated in this investigation. In addition, a single case study of the kettlebell swing was performed on an accomplished kettlebell master. Electromyography, ground reaction forces (GRFs), and 3D kinematic data were recorded during exercises using a 16-kg kettlebell. These variables were input into an anatomically detailed biomechanical model that used normalized muscle activation; GRF; and spine, hip, and knee motion to calculate spine compression and shear loads. It was found that kettlebell swings create a hip-hinge squat pattern characterized by rapid muscle activation-relaxation cycles of substantial magnitudes (∼50% of a maximal voluntary contraction [MVC] for the low back extensors and 80% MVC for the gluteal muscles with a 16-kg kettlebell) resulting in about 3,200 N of low back compression. Abdominal muscular pulses together with the muscle bracing associated with carries create kettlebell-specific training opportunities. Some unique loading patterns discovered during the kettlebell swing included the posterior shear of the L4 vertebra on L5, which is opposite in polarity to a traditional lift. Thus, quantitative analysis provides an insight into why many individuals credit kettlebell swings with restoring and enhancing back health and function, although a few find that they irritate tissues.
本研究旨在量化不同壶铃摆动和搬运时的脊柱负荷。在壶铃运动中，没有发现之前关于组织负荷的研究。鉴于壶铃的流行，本研究旨在深入了解由此产生的关节负荷。7 名男性受试者参与了这项研究。此外，对一位经验丰富的壶铃大师进行了壶铃摆动的单一案例研究。在使用 16 公斤壶铃进行运动时，记录了肌电图、地面反作用力 (GRF) 和 3D 运动学数据。这些变量被输入到一个解剖学上详细的生物力学模型中，该模型使用归一化肌肉激活、GRF 和脊柱、臀部和膝盖运动来计算脊柱压缩和剪切负荷。结果发现，壶铃摆动产生了一种髋关节铰链深蹲模式，其特点是肌肉快速激活-松弛循环的幅度很大（对于下背部伸展肌，大约为最大自主收缩 [MVC] 的 50%，对于臀肌，大约为 80%，使用 16 公斤的壶铃），导致下背部压缩约 3200N。腹部肌肉脉冲加上搬运时与肌肉支撑相关的肌肉收缩，创造了壶铃特有的训练机会。在壶铃摆动过程中发现的一些独特的加载模式包括 L4 椎骨在 L5 上的后向剪切，其极性与传统的提升相反。因此，定量分析提供了一个深入了解为什么许多人认为壶铃摆动可以恢复和增强背部健康和功能的原因，尽管有些人发现它们会刺激组织。
