全身质量估计和反运动跳跃中的错误传播:模拟错误研究
Jenna K Burnett1, Yong-Woon Kim1,2, Hyun Joon Kwon1
1Department of Kinesiology, University of Maryland, College Park, MD, USA.
Sports biomechanics
|August 9, 2023
概括
模拟质量错误在体育医学中显著影响跳跃高度计算. 即使在人体质量估计中的小错误也可能导致对运动表现和功率输出的不准确评估.
科学领域:
- 生物力学 生物力学
- 运动医学 运动医学
- 人类运动分析 人类运动分析
背景情况:
- 高速度运动,如跳跃,对于运动表现至关重要,并使用跳跃特征进行评估.
- 基于地面反应力 (GRF) 的方法是计算跳跃指标的标准,但依赖于准确的质量估计.
- 质量估计中的不准确性可能导致计算跳跃结果中的错误,影响性能分析.
研究的目的:
- 为了研究模拟质量错误在反运动跳跃期间对质量中心 (CoM) 轨迹的影响.
- 量化质量误估对跳跃高度计算的影响.
- 为了评估错误在整个跳跃轨迹的传播.
主要方法:
- 从静态的GRF估计了质量,并添加了模拟错误 (正负).
- 使用基于GRF的方法计算了CoM轨迹,并改变了质量值.
- 使用统计分析,包括回归和双向ANOVA来确定跳跃高度上的质量误差的意义.
主要成果:
- 估计质量的1公斤变化导致计算跳跃高度的7.7厘米变化.
- 最大和最小模拟质量误差之间的跳跃高度差异为11.5±0.4厘米.
- 观察到跳跃高度的显著差异,质量误差小于±0.2公斤或±0.4公斤.
结论:
- 体质估计中的小错误可能导致跳跃高度计算中的重大不准确性.
- 这些质量错误可以在整个跳跃轨迹中传播,可能导致关于性能的错误结论.
- 建议在使用基于GRF的方法来分析跳跃高度作为功率的代理时谨慎使用,这是因为对质量估计错误的敏感性.
相关概念视频
Center of Mass: Introduction
14.5K
Any object that obeys Newton's second law of motion is made up of a large number of infinitesimally small particles. Objects in motion can be as simple as atoms or as complex as gymnasts performing in the Olympics. The motion of such objects is described about a point called the center of mass of the object. The center of mass of an object is a point that acts as if the whole mass is concentrated at that point. The center of mass of an object with a large number of infinitesimally small...
14.5K
Force and Momentum
15.9K
Force and momentum are intimately related. Force acting over time can change momentum, and Newton's second law of motion can be stated in its most broadly applicable form in terms of momentum. Momentum can be applied to systems where the mass is changing, such as rockets, as well as to systems of constant mass. Also, momentum continues to be a key concept in the study of atomic and subatomic particles in quantum mechanics. One can consider systems with varying mass in some detail; however,...
15.9K
Significance of Center of Mass
6.6K
The center of mass of an object is defined as the mass-weighted average position of all the particles that comprise the object. The significance of the center of mass of an object can be seen by looking at its dynamics. The time derivative of the center of mass gives its velocity, assuming that the object's mass remains constant over time. Furthermore, the total linear momentum of an object can be seen as the linear momentum of a single particle of the object's total mass moving with...
6.6K
Center of Mass
1.2K
The center of mass is the point at which the total mass of an object can be said to be concentrated. It is a fundamental principle in mechanics and physics that applies to all objects regardless of their shape or size. The center of gravity is the point at which an object’s weight appears to be concentrated and can be used to balance the object perfectly.
The knowledge of the center of mass can also help us to describe and predict the motion of objects. For example, when a ball is thrown...
The knowledge of the center of mass can also help us to describe and predict the motion of objects. For example, when a ball is thrown...
1.2K
Conservation of Mass in Moving, Nondeforming Control Volume
1.1K
Stormwater detention basins are essential in managing runoff during heavy rainfall, particularly in urban areas where impervious surfaces increase the risk of flooding. Understanding the conservation of mass in these systems allows engineers to optimize basin performance, balancing inflow, outflow, and water storage.
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
1.1K
Equation of Motion: Center of Mass
173
The equation of motion for a single particle can be expanded to encompass a system of particles consisting of n particles. For any arbitrarily chosen particle within this system, the net force acting upon it is the aggregate of both internal and external forces. Extending this principle to all particles within the system results in the equation of motion for the entire assembly.
Internal forces between any pair of particles manifest as collinear pairs of equal magnitude but opposite directions,...
Internal forces between any pair of particles manifest as collinear pairs of equal magnitude but opposite directions,...
173


