School of Sport Science, Exercise and Health, The University of Western Australia, Perth, Australia.
Med Sci Sports Exerc. 2013 Apr;45(4):778-83. doi: 10.1249/MSS.0b013e31827973d1.
This study aimed to analyze lumbo-pelvic lateral flexion kinematics and kinetics in junior fast bowlers and compare bowlers with varying quadratus lumborum (QL) cross-sectional area (CSA) asymmetry profiles.
Magnetic resonance imaging was used to determine QL CSA of 39 participants who also underwent three-dimensional analysis of their bowling action.
Bowlers with greater than 10% QL asymmetry (n = 26) experienced a larger peak lumbo-pelvic lateral flexion; angle (21.6° ± 4.2°), angular velocity (314.9°·s ± 86.6°·s), moment (12.8 ± 2.5 N·m·kg·m), positive power (25.6 ± 12.6 W·kg·m), and negative power (48.6 ± 20.9 W·kg·m) compared with the bowlers with less than 10% asymmetry (n = 13) (angle = 18.1° ± 1.9°, angular velocity = 243.8°·s ± 64.9°·s, moment = 10.4 ± 2.8 N·m·kg·m, positive power = 14.7 ± 7.4 W·kg·m, and negative power = 33.8 ± 17.7 W·kg·m; P < 0.05).
Fast bowlers with QL CSA asymmetry in excess of 10% experience increased lumbo-pelvic lateral flexion loads during bowling. As increased lateral flexion loads may increase the risk of spondylolysis development, the presence of large QL asymmetry may be a useful screening tool for identifying bowlers at risk of developing lumbar spondylolysis.
本研究旨在分析青少年快速投球手的腰椎骨盆横向屈伸运动学和动力学，并比较腰椎旁肌（QL）横截面积（CSA）不对称程度不同的投球手。
使用磁共振成像（MRI）确定 39 名参与者的 QL CSA，这些参与者还接受了他们投球动作的三维分析。
QL 不对称大于 10%的投球手（n = 26）经历了更大的腰椎骨盆横向屈伸峰值角度（21.6°±4.2°）、角速度（314.9°·s±86.6°·s）、力矩（12.8±2.5 N·m·kg·m）、正功率（25.6±12.6 W·kg·m）和负功率（48.6±20.9 W·kg·m），而 QL 不对称小于 10%的投球手（n = 13）的角度为 18.1°±1.9°，角速度为 243.8°·s±64.9°·s，力矩为 10.4±2.8 N·m·kg·m，正功率为 14.7±7.4 W·kg·m，负功率为 33.8±17.7 W·kg·m；P < 0.05）。
QL CSA 不对称超过 10%的快速投球手在投球时会经历更大的腰椎骨盆横向屈伸负荷。由于增加的横向屈伸负荷可能会增加发生脊椎裂的风险，因此 QL 较大的不对称可能是识别有发生腰椎脊椎裂风险的投球手的有用筛查工具。
