Purpose: The factors associated with low back pain (LBP) and the relationship between LBP and ball velocity during kicking motion of adolescent soccer players remain largely unknown. This study aims to clarify the relationship between increasing ball velocity and LBP in adolescent soccer players.
Participants and Methods: Adolescent soccer players were divided into two groups according to the presence and absence of LBP (LBP group, n=38 and NBP (no back pain) group, n=29, respectively). Real-time kick motion was measured using a three-dimensional motion analysis system and the angle of the lumbar spine, hip, and center of mass (COM) were calculated. Regression analysis was used to identify factors associated with ball velocity and LBP. In addition, Pearson’s correlation coefficients were determined between the angle of the lumbar spine and hip, and ball velocity and position of COM in the extracted phase from regression analysis.
Results: The major factor associated with increasing ball velocity was the rotation angle of both hips (Adjusted R²=0.244) and vertical position of COM during kicking (Adjusted R²=0.262). Furthermore, the factors associated with LBP were the flexion angle of kick-side hip (OR=1.126) and abduction angle of both hips (kick-side OR=1.124; support-side OR=0.872). The factors for ball velocity and LBP were related to the maximum hip extension phase. In the hip extension phase of kicking, compared with the NBP group, the LBP group showed lesser extension and external rotation of the kick-side hip angle. In the hip flexion phase of kicking, the ball velocity was correlated with vertical (r=0.56)/anterior (r=0.46) position of COM in the NBP group.
Conclusion: To compensate for this restricted hip motion, the LBP group could extend and rotate their lumbar spine, which may likely cause stress to this region.

Keywords: kick motion, low back pain, lumbar spine, hip, adolescent


中文翻译：

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青少年足球运动员踢球时与球速度和腰痛相关的因素

目的：与腰痛（LBP）相关的因素以及青少年足球运动员踢球时腰痛与球速之间的关系仍然很大程度上未知。本研究旨在阐明青少年足球运动员提高球速和腰痛之间的关系。
参与者和方法：根据LBP的存在和不存在将青少年足球运动员分为两组（LBP组，n = 38和NBP（无背痛）组，n = 29，分别）。使用三维运动分析系统测量实时踢腿运动，并计算腰椎、臀部和质心 (COM) 的角度。回归分析用于确定与球速和腰痛相关的因素。此外，在回归分析的提取阶段，确定了腰椎和髋关节角度与球速度和 COM 位置之间的 Pearson 相关系数。
结果：与球速度增加相关的主要因素是双髋的旋转角度（调整后的 R ²=0.244）和COM在踢球过程中的垂直位置（调整后的R ² =0.262）。此外，与LBP相关的因素是踢侧髋关节屈曲角度（OR=1.126）和双髋外展角（踢侧OR=1.124；支撑侧OR=0.872）。球速度和LBP的因素与最大髋关节伸展阶段有关。在踢腿伸髋阶段，与NBP组相比，LBP组踢腿侧髋角的伸展和外旋较小。在踢腿的髋关节屈曲阶段，球速度与 NBP 组 COM 的垂直（r=0.56）/前（r=0.46）位置相关。
结论：为了补偿这种受限的髋关节运动，LBP 组可以伸展和旋转他们的腰椎，这可能会对该区域造成压力。

关键词：踢腿动作，腰痛，腰椎，髋关节，青少年