Faculty of Sports Science, Chulalongkorn University, Bangkok, Thailand; and.
School of Medical and Health Sciences, Edith Cowan University, Perth, Australia.
J Strength Cond Res. 2021 Nov 1;35(11):2999-3005. doi: 10.1519/JSC.0000000000004074.
Songsupap, T, Newton, RU, and Lawsirirat, C. Balancing injury risk and power development by weighted jump squat through controlling eccentric loading. J Strength Cond Res 35(11): 2999-3005, 2021-Weighted jump squat (WJS) training is highly effective for increasing neuromuscular power but entails higher injury risk than traditional resistance training because of the impact of landing. Braking mechanisms can be used to control the landing impact; however, the optimal eccentric loading condition that balances injury risks and power output is still unclear. The purpose of this study was to assess different eccentric braking conditions. Twenty-two male varsity basketball players aged 20.8 ± 1.1 years and a 1 repetition maximum (1RM) of back squat-to-body mass ratio of 2.0 ± 0.2 participated in the study. The subjects performed 2 sets of WJS of 6 repetitions with additional 30% of 1RM load under 4 randomly assigned conditions: (a) traditional load, no braking (B0), (b) 25% braking load reduction during landing (B25), (c) 50% braking load reduction during landing (B50), and (d) 100% braking load reduction during landing with release at touchdown (B100R). A repeated measures analysis of variance was used to determine differences of dependent variables: peak power output, peak force, peak velocity, and impulse. B100R resulted in statistically lower eccentric peak force and impulse for the first 50 milliseconds than the other 3 conditions (p < 0.05), but the largest concentric peak power. Furthermore, B0 resulted in statistically lower concentric peak power and peak velocity than the other 3 conditions (p < 0.05). We suggest that B100R was a more favorable loading condition that balanced injury risk and power production in WJS.
宋萨帕、T、牛顿、RU 和劳西里拉特 C 通过控制偏心负载来平衡伤风险和力量发展的负重深蹲。J 力量与调节研究 35（11）：2999-3005，2021-负重深蹲（WJS）训练对于增加神经肌肉力量非常有效，但由于着陆的影响，比传统的抗阻训练风险更高。制动机制可用于控制着陆冲击；然而，平衡伤风险和力量输出的最佳偏心负载条件仍不清楚。本研究的目的是评估不同的偏心制动条件。22 名年龄 20.8 ± 1.1 岁的男性大学篮球队员和深蹲至体重比为 2.0 ± 0.2 的 1 重复最大（1RM）参加了研究。受试者在 4 种随机分配的条件下进行了 2 组 6 次重复的 WJS，外加 30%的 1RM 负荷：（a）传统负荷，无制动（B0），（b）着陆时制动负荷减少 25%（B25），（c）着陆时制动负荷减少 50%（B50），以及（d）着陆时制动负荷减少 100%并在触地时释放（B100R）。采用重复测量方差分析来确定依赖变量的差异：峰值功率输出、峰值力、峰值速度和冲量。B100R 在最初的 50 毫秒内导致偏心峰值力和冲量明显低于其他 3 种情况（p < 0.05），但产生的最大向心峰值功率。此外，B0 导致向心峰值功率和峰值速度明显低于其他 3 种情况（p < 0.05）。我们建议 B100R 是一种更有利的负载条件，可以平衡 WJS 中的伤风险和力量产生。
