Background: During ballet, injuries to the Achilles tendon are associated with the take-off phase of various jumps.
Research question: The purpose of the study was to assess differences in mechanical demand on the body, specifically at the ankle, in two single-leg jumps commonly trained in ballet: a saut de chat (SDC) and a temps levé (TL).
Methods: Fifteen classically trained female dancers had 16 reflective markers placed on the lower body and each dancer performed each jump three times on a force plate. The marker position data and ground reaction forces (GRF) were captured synchronously at 250 Hz and 1000 Hz, respectively. Peak vertical GRF, mean rate of force development (RFD), peak ankle moment, and peak ankle power were determined and averaged across trials. Paired t-tests were used to determine differences between the SDC and the TL.
Results: When compared to the TL, the SDC displayed significantly higher peak vertical GRF (p = 0.003), RFD (p = 0.002), and peak ankle moment and power (p < 0.001). The effect sizes for these differences were large for all variables (Cohen’s d > 0.80).
Conclusion: The mechanical demand at the ankle joint is significantly greater for the SDC than the TL.



中文翻译：

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在受过经典训练的芭蕾舞演员的短时聊天和临时跳高期间，踝关节的机械要求

背景：在芭蕾比赛中，跟腱受伤与各种跳步的起飞阶段有关。
研究问题：该研究的目的是评估两个通常在芭蕾舞中训练过的单腿跳对身体的机械需求（特别是在脚踝处）的差异：跳动聊天（SDC）和临时跳动（TL）。
方法： 15名受过经典训练的女舞者的下半身有16个反光标记，每位舞者在推力板上进行了3次跳跃。分别以250 Hz和1000 Hz同步捕获标记位置数据和地面反作用力（GRF）。确定峰值垂直GRF，平均力量发展率（RFD），峰值踝关节力矩和峰值踝关节力量，并在各个试验中平均。配对的t检验用于确定SDC和TL之间的差异。
结果：与TL相比，SDC的峰值垂直GRF（p = 0.003），RFD（p = 0.002）和踝关节力矩和力量峰值（p <0.001）明显更高。对于所有变量，这些差异的影响大小均很大（Cohen d > 0.80）。
结论：对于SDC，踝关节的机械需求明显大于TL。