Background. The kinematics of a controlled functional task in female volleyball athletes may be an interesting area of study. Therefore, investigating if there are kinematic changes in a jump landing jump task among female athletes with low back pain (LBP) may help therapists and trainers better prevent and/or rehabilitate LBP in athletes. Objectives. The purpose of this study was to examine lumbopelvic and lower extremity kinematics in athletes with persistent LBP during a jumping task. Methods. A comparative cross sectional study conducted in a university research laboratory. Professional female volleyball players with (n = 20) and without (n = 18) LBP were recruited from the Iranian female volleyball league. To reduce heterogeneity, one particular subgroup of athletes with LBP were selected. Kinematic data including lumbar extension, hip flexion, rotation and adduction and knee flexion and abduction angles when the center of mass was at minimum height during a jump-landing-jump maneuver were collected using a Vicon motion analysis system and analysed using MATLAB software. Independent t-tests were used to compare mean values between the groups. Results. Athletes with LBP had significantly greater hip flexion (LBP: -73.62±11.06 ̊; Control: 62.88±7.03 ̊, p=0.016) and significantly less knee flexion (LBP: 77.06±7.27 ̊, Control: 81.62±4.70 ̊, p=0.029) at the lowest point of the jump than athletes without LBP. There were no other significant differences between the groups (p>0.05). Conclusion. A subgroup of female athletes with LBP display altered lower extremity kinematics during a jump task than athletes without LBP. This may have important implications for lower limb performance and injury.

中文翻译：

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持续性下腰痛运动员跳跃过程中下肢运动学的改变

背景。女子排球运动员受控功能性运动的运动学可能是一个有趣的研究领域。因此，调查下腰痛（LBP）的女运动员的跳着地跳动作是否发生运动学变化，可以帮助治疗师和教练更好地预防和/或恢复运动员的LBP。目标。这项研究的目的是检查在跳跃任务期间具有持续性LBP的运动员的腰椎和下肢运动学。方法。在大学研究实验室中进行的比较横断面研究。从伊朗女排联赛中招募了（n = 20）和没有（n = 18）LBP的职业女排运动员。为了减少异质性，选择了具有LBP的运动员的一个特定子组。运动数据，包括腰椎伸展，使用Vicon运动分析系统收集跳跃-着陆-跳跃动作期间质心处于最小高度时的髋部弯曲，旋转和内收以及膝部弯曲和外展角度，并使用MATLAB软件进行分析。使用独立的t检验比较两组之间的平均值。结果。患有LBP的运动员的髋关节屈曲明显更大（LBP：-73.62±11.06̊;对照：62.88±7.03̊，p = 0.016），膝关节屈曲明显更少（LBP：77.06±7.27̊，对照：81.62±4.70̊，p =比没有LBP的运动员在跳高的最低点（0.029）。两组之间没有其他显着差异（p> 0.05）。结论。与没有LBP的运动员相比，一个具有LBP的女运动员亚组在跳跃任务中显示出其下肢运动学改变。