■个人最大关节和节段角速度与棒球投手的投掷臂动力学和球速度呈正相关。
■为了观察累积的最大关节和节段角速度,不管顺序,影响高中投手的球速度和投掷臂动力学。
■描述性实验室研究。
■高中(n=55)投手投掷了8到12个快球投球,同时使用3维运动捕捉(480Hz)进行评估。最大关节和节段角速度(导线膝部伸展,骨盆旋转,躯干旋转,肩部内旋,和前臂旋前)对每个投手进行计算。投手被归类为整体快速,整体缓慢,或每个关节或分段速度子类别的高速度,或者作为人口,任何有资格被包括在多个子类别中的投手。使用t检验与事后回归和多变量回归模型来预测投掷臂动力学和球速度,在各个子组中比较了运动学和动力学参数。分别。
■与人群相比,铅膝关节伸展和骨盆旋转速度亚组实现了显着更高的归一化肘部内翻扭矩(P=.016)和肘部屈曲扭矩(P=.018),具有等效球速度(P=.118)。最大骨盆旋转速度每增加1-SD(87deg/s),标准化的肘部撑开力增加了4.7%体重(BW)(B=0.054;β=0.290;P=0.013)。总体快速组年龄较大(平均值±标准差,16.9±1.4vs15.4±0.9年;P=.007),球速度快8.9英里/小时(32.7±3.1vs28.7±2.3m/s;P=.002),并且具有明显更高的肩部内部旋转扭矩(63.1±17.4vs43.6±12.0Nm;P=.005),肘内翻扭矩(61.8±16.4vs41.6±11.4Nm;P=.002),与整体慢组相比,肘部屈曲扭矩(46.4±12.0vs29.5±6.8Nm;P<.001)。基于最大关节和节段角速度和人体测量学的球速度多元回归模型预测了53.0%的方差。
■高中投手具有较高的最大关节和节段速度,不管顺序,显示出年龄较大,球速度较快,但以增加的肩膀和肘部动力学为代价。
■投手和教练组应该考虑在更快的球速度和增加的投掷臂动力学之间的权衡,已确定的肘部损伤的危险因素。
UNASSIGNED: Individual maximum joint and segment angular velocities have shown positive associations with throwing arm kinetics and ball velocity in
baseball pitchers.
UNASSIGNED: To observe how cumulative maximum joint and segment angular velocities, irrespective of sequence, affect ball velocity and throwing arm kinetics in high school pitchers.
UNASSIGNED: Descriptive laboratory study.
UNASSIGNED: High school (n = 55) pitchers threw 8 to 12 fastball pitches while being evaluated with 3-dimensional motion capture (480 Hz). Maximum joint and segment angular velocities (lead knee extension, pelvis rotation, trunk rotation, shoulder internal rotation, and forearm pronation) were calculated for each pitcher. Pitchers were classified as overall fast, overall slow, or high velocity for each joint or segment velocity subcategory, or as population, with any pitcher eligible to be included in multiple subcategories. Kinematic and kinetic parameters were compared among the various subgroups using t tests with post hoc regressions and multivariable regression models created to predict throwing arm kinetics and ball velocity, respectively.
UNASSIGNED: The lead knee extension and pelvis rotation velocity subgroups achieved significantly higher normalized elbow varus torque (P = .016) and elbow flexion torque (P = .018) compared with population, with equivalent ball velocity (P = .118). For every 1-SD increase in maximum pelvis rotation velocity (87 deg/s), the normalized elbow distractive force increased by 4.7% body weight (BW) (B = 0.054; β = 0.290; P = .013). The overall fast group was older (mean ± standard deviation, 16.9 ± 1.4 vs 15.4 ± 0.9 years; P = .007), had 8.9-mph faster ball velocity (32.7 ± 3.1 vs 28.7 ± 2.3 m/s; P = .002), and had significantly higher shoulder internal rotation torque (63.1 ± 17.4 vs 43.6 ± 12.0 Nm; P = .005), elbow varus torque (61.8 ± 16.4 vs 41.6 ± 11.4 Nm; P = .002), and elbow flexion torque (46.4 ± 12.0 vs 29.5 ± 6.8 Nm; P < .001) compared with the overall slow group. A multiregression model for ball velocity based on maximum joint and segment angular velocities and anthropometrics predicted 53.0% of variance.
UNASSIGNED: High school pitchers with higher maximum joint and segment velocities, irrespective of sequence, demonstrated older age and faster ball velocity at the cost of increased throwing shoulder and elbow kinetics.
UNASSIGNED: Pitchers and coaching staff should consider this trade-off between faster ball velocity and increasing throwing arm kinetics, an established risk factor for elbow injury.