根据不同的竞争水平,乳房和蝶间循环的动力变化与统计参数映射分析
Aléxia Fernandes1, Mário J Costa1, Bruno Mezêncio2
1Centre of Research, Education, Innovation and Intervention in Sport and Porto Biomechanics Laboratory, Faculty of Sport, University of Porto, Porto, Portugal.
Journal of biomechanics
|October 25, 2024
概括
精英游泳者表现出卓越的冲刺胸和蝶技巧,显示出明显的运动变化. 虽然保持了胸部冲动的一致性,但蝶显示速度衰减,突出了游泳力学技能水平的差异.
科学领域:
- 生物力学 生物力学
- 运动科学 运动科学 运动科学
- 发动机控制器的控制器
背景情况:
- 胸和蝶需要先进的运动技能才能有效地推进.
- 了解循环间的动力学变化对于区分游泳者的专业知识至关重要.
- 协调的力相互作用是游泳表现的关键.
研究的目的:
- 分析精英和国家级游泳者之间的胸部冲刺和蝶冲刺的跨周期动力学变化.
- 根据技能水平,识别游泳技巧和表现指标的差异.
- 研究竞技游泳者的运动模式和冲刺表现之间的关系.
主要方法:
- 20名精英和15名国家级游泳运动员在胸和蝶比赛中进行了25米短跑.
- 水下摄像头 (120 Hz) 捕获了角平面运动.
- 分析包括平均/最大/最小速度,中风速/长度,周期内变化和相位持续时间;统计参数映射用于组间比较.
主要成果:
- 精英游泳者表现出明显更高的平均速度和最大速度在胸部.
- 精英游泳者表现出优越的平均,最大和最小速度,以及与国家级游泳者相比的蝶中风率.
- 虽然胸部冲动在技能水平上显示出一致的循环间动力学,但蝶则表现出平均速度衰减,变化与上肢恢复和横扫阶段有关.
结论:
- 技能水平在冲刺,胸和蝶中显著影响技术和战略执行.
- 精英游泳者拥有更精细的动力学配置,特别是在蝶推进中.
- 尽管表现不同,精英和国家级游泳运动员在连续的游泳周期之间表现出相似的速度变化.
相关概念视频
Energy Conservation and Bernoulli's Equation
Applying the conservation of energy principle or the work-energy theorem to an incompressible, inviscid fluid in laminar, steady, irrotational flow leads to Bernoulli's equation. It states that the sum of the fluid pressure, potential, and kinetic energy per unit volume is constant along a streamline.
All the terms in the equation have the dimension of energy per unit volume. The kinetic energy per unit volume is called the kinetic energy density, and the potential energy per unit volume is...
All the terms in the equation have the dimension of energy per unit volume. The kinetic energy per unit volume is called the kinetic energy density, and the potential energy per unit volume is...
Bernoulli's Equation for Flow Along a Streamline
Bernoulli's equation relates the energy conservation in a fluid moving along a streamline. The equation applies to incompressible and inviscid fluids under steady flow. For such a flow, Newton's second law is applied to a small fluid element, which experiences forces due to pressure differences, gravity, and velocity variations. The force balance leads to the following form of Bernoulli's equation:
The Buckingham Pi Theorem
The Buckingham Pi theorem provides a structured method to simplify fluid dynamics problems by reducing complex systems of variables to dimensionless terms.
Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
Design Example: Creating a Hydraulic Model of a Dam Spillway
Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.


