Aso Takuya, Kagaya Yoshinori
Showa University Research Institute for Sport and Exercise Sciences, Kanagawa, Japan.
Department of Physical Therapy, Showa University School of Nursing and Rehabilitation Sciences, Kanagawa, Japan.
JSES Int. 2024 Apr 3;8(4):740-745. doi: 10.1016/j.jseint.2024.03.008. eCollection 2024 Jul.
The shoulder motion during pitching is influenced by the trunk and pelvis motions, but their relationship during the deceleration phase of throwing on flat ground has not yet been clarified. This study aimed to investigate the relationship between shoulder, trunk, and pelvis kinematics at the maximum internal rotation (MIR) of the shoulder during the deceleration phase of throwing on flat ground.
The study participants included 17 male baseball players over 20 years old and at the recreational playing level. The recreational level was illustrated by players who did not practice at high intensity and had played only 1-2 competitions per week. Reflective markers were applied to the subject, and throwing motion was assessed using a three-dimensional motion capture system. Data were captured at 1000 Hz. We assessed the angle of the shoulder, spine, and pelvis at the MIR on flat ground. Internal shoulder rotation velocity and spinal and pelvic angular velocities were also assessed. The relationship between the shoulder, spine, and pelvis kinematics at the MIR was examined using simple linear regression analysis.
The internal shoulder rotation angle at the MIR was negatively associated with only the spinal flexion and rotation angle at the MIR ( = .006 and = .010, respectively). No other significant associations between shoulder, spine, and pelvis kinematics were detected at the MIR.
For throwing on flat ground, the internal shoulder rotation motion may be suppressed by producing trunk flexion and rotation motion at the MIR.
投球时肩部的运动受躯干和骨盆运动的影响，但在平地上投掷减速阶段它们之间的关系尚未阐明。本研究旨在探讨在平地上投掷减速阶段肩部最大内旋（MIR）时肩部、躯干和骨盆的运动学关系。
研究参与者包括17名20岁以上的男性棒球运动员，处于业余水平。业余水平由那些没有进行高强度训练且每周只参加1-2场比赛的球员体现。在受试者身上粘贴反光标记，并使用三维运动捕捉系统评估投掷动作。数据以1000Hz的频率采集。我们评估了平地上MIR时肩部、脊柱和骨盆的角度。还评估了肩部内旋速度以及脊柱和骨盆的角速度。使用简单线性回归分析检查MIR时肩部、脊柱和骨盆运动学之间的关系。
MIR时肩部内旋角度仅与MIR时的脊柱前屈和旋转角度呈负相关（分别为 = 0.006和 = 0.010）。在MIR时未检测到肩部、脊柱和骨盆运动学之间的其他显著关联。
对于在平地上投掷，在MIR时产生躯干前屈和旋转运动可能会抑制肩部内旋运动。
