投球类型及其对肘部扭矩和旋转率的影响在职业棒球投手中的投球类型
Alexander J Hodakowski1, Brittany Dowling2, John T Streepy3
1Duke University Medical Center, Durham, North Carolina, USA.
The American journal of sports medicine
|January 21, 2025
概括
职业投手的肘部受伤率很高. 快球投球产生了最高的肘部瓦鲁斯扭矩,表明投球类型是关键的风险因素,而不是旋转率.
科学领域:
- 运动医学 运动医学
- 生物力学 生物力学
- 棒球投球分析 棒球投球分析
背景情况:
- 在职业棒球投手中,肘部受伤,包括侧带重建,是很常见的.
- 关于投球类型,球速和旋转速率对肘部瓦鲁斯扭矩和受伤风险的影响的先前研究仍然没有确定性.
研究的目的:
- 分析专业投手在不同类型的球场 (快球,曲球,换球,滑球) 中的肘部瓦鲁斯扭矩,累积扭矩和加载率.
- 为了研究球旋转在投球过程中对肘部生物力学的影响.
主要方法:
- 一项描述性的实验室研究,涉及31名职业投手.
- 使用运动捕捉 (480 Hz) 和TrackMan技术来记录投球数据.
- 计算的肘部瓦鲁斯扭矩,加载率,累积扭矩和旋转率,对于每个投球类型.
主要成果:
- 与其他球场相比,快球表现出明显更高的球速度,肘的峰值扭矩和累积扭矩.
- 更换显示了第二高的累积扭矩,而曲线球则是最低的.
- 不过,在两种音调类型之间,旋转速率和肘部扭矩之间没有发现显著的相关性.
结论:
- 投球类型是专业投球员肘部瓦鲁斯扭矩和加载率的重要决定因素.
- 旋转速率似乎不是肘部扭矩或受伤风险的可靠预测指标.
- 在评估投者肘部受伤风险时,投类型应优先考虑旋转率.
相关概念视频
Motion of a Projectile
695
Projectile motion becomes evident when a player kicks the ball into the air. The launch angle, or the angle at which the ball is kicked, plays a crucial role in determining the trajectory of the projectile. As the ball soars through the air, influenced solely by gravity, its motion can be dissected into two independent velocity components: the horizontal and the vertical.
Horizontal motion, governed by the initial kick, maintains a constant velocity throughout the flight of the soccer ball.
Horizontal motion, governed by the initial kick, maintains a constant velocity throughout the flight of the soccer ball.
695
Angle of Twist - Elastic Range
271
Consider a cylindrical shaft with a length denoted by L and a consistent cross-sectional radius referred to as r. This shaft undergoes a torque at the free end. The highest shearing strain within the shaft is directly proportional to the twist angle and the radial distance from the shaft axis. When the shaft behaves elastically, this shearing strain can be articulated using variables such as the applied torque, radial distance, the polar moment of inertia, and the modulus of rigidity. By...
271
Torque
14.9K
Torque is an important quantity for describing the dynamics of a rotating rigid body. We see the application of torque in many ways in the world, such as when pressing the accelerator in a car, which causes the engine to apply additional torque on the drivetrain. Here, we define torque and provide a framework to create an equation to calculate torque for a rigid body with fixed-axis rotation.
Torque can be considered as the rotational counterpart to force. Since forces change the translational...
Torque can be considered as the rotational counterpart to force. Since forces change the translational...
14.9K
Residual Stresses in Circular Shafts
155
In materials that exhibit elastic and plastic behavior, known as elastoplastic materials, residual stresses can accumulate when these materials experience plastic deformation. This deformation arises from either high levels of shearing stress or significant strains. Residual stresses are internal stresses that persist within a material after removing the external force causing deformation. This phenomenon is demonstrated when observing the behavior of a shaft under torque; notably, the...
155
Angle of Twist: Problem Solving
257
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the...
257
Spin–Spin Coupling Constant: Overview
864
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
864


