La Greca Stefano, Antonacci Gaetano, Marinelli Stefano, Cifelli Pierangelo, Di Giminiani Riccardo
Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
Front Sports Act Living. 2024 Oct 24;6:1474537. doi: 10.3389/fspor.2024.1474537. eCollection 2024.
The drop vertical jump (DVJ) is extensively utilized for conditioning and evaluating physical performance, as well as reducing the likelihood of injury by enhancing joint stability through the coactivation of muscles acting on the joint. The execution of DVJ can be controlled by verbal instructions and evaluated by the vertical ground reaction force (vGRF)-time profile.
Our hypothesis was that varying verbal instructions could have an impact on the DVJ's parameter, thereby optimizing vertical performance and minimizing the impact during landing in young female volleyball players. Sixteen female volleyball players volunteered to participate in this study (age: 21.3 ± 2.6 years; stature: 1.66 ± 0.1 m; body mass: 62.0 ± 8.1 kg and BMI: 22.2 ± 1.8). They executed DVJs following verbal instructions ranging from "jump as high as possible" (1A), "jump as quickly as possible" (2A), "jump as high as possible and during the landing attempt to dampen the impact at ground contact" (1B), and "jump as high as quickly as possible and during the landing attempt to damp the impact at ground contact" (2B). The reactive strength index (RSI), vGRF (1st and 2nd peaks), and flight time (FT) were evaluated.
The verbal instructions 1A improved the FT and the first peak of the vGRF ( < 0.05), whereas 2A the RSI ( < 0.05). On the contrary, "the damping" required in the 1B, and 2B verbal instruction reduced the 2nd peak of vGRF ( < 0.05), without altering the task required during the jump ( < 0.05).
The instructions provided for the final landing (the second peak of vGRF) have the potential to enhance safety by reducing the peak of vGRF without affecting the performance required during the jump. When designing DVJ training, coaches or kinesiologists must consider the use of verbal instructions to induce specific adaptation over time.
The present study supports the use of specific verbal instructions to reduce impact forces in landing and injury risk.
下落垂直跳（DVJ）被广泛用于体能训练和身体性能评估，并且通过共同激活作用于关节的肌肉来增强关节稳定性，从而降低受伤的可能性。DVJ的执行可以通过口头指令来控制，并通过垂直地面反作用力（vGRF）-时间曲线进行评估。
我们的假设是，不同的口头指令可能会对DVJ的参数产生影响，从而优化年轻女排运动员的垂直性能并减少落地时的冲击力。16名女排运动员自愿参加本研究（年龄：21.3±2.6岁；身高：1.66±0.1米；体重：62.0±8.1千克；体重指数：22.2±1.8）。她们按照“尽可能跳得高”（1A）、“尽可能快地跳”（2A）、“尽可能跳得高，并在落地时尝试减轻地面接触时的冲击力”（1B）以及“尽可能快且高地跳，并在落地时尝试减轻地面接触时的冲击力”（2B）等口头指令进行DVJ。评估反应力量指数（RSI）、vGRF（第一和第二峰值）以及飞行时间（FT）。
口头指令1A提高了FT和vGRF的第一个峰值（<0.0），而2A提高了RSI（<0.05）。相反，1B和2B口头指令中要求的“缓冲”降低了vGRF的第二个峰值（<0.05），而不改变跳跃过程中所需的任务（<0.05）。
为最终落地（vGRF的第二个峰值）提供的指令有可能通过降低vGRF的峰值来提高安全性，而不影响跳跃过程中所需的性能。在设计DVJ训练时，教练或运动机能学家必须考虑使用口头指令来随着时间的推移诱导特定的适应性变化。
本研究支持使用特定的口头指令来降低落地时的冲击力和受伤风险。
