Abstract：
BACKGROUND: Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction.
OBJECTIVE: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike?
METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson\'s correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles.
RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint\'s positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80).
CONCLUSIONS: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.
OBJECTIVE: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike?
METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson\'s correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles.
RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint\'s positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80).
CONCLUSIONS: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.
摘要：
背景：着陆后初次接触（IC）时，前交叉韧带（ACL）损伤可能与下肢角度和主要和非主要腿的生物力学因素相关。本研究旨在研究职业排球运动员在扣球后着陆过程中，在IC的三个轴上的脚踝角度与膝盖和髋关节角度之间的相关性，前和后疲劳诱导。
目的：疲劳在多大程度上影响下肢关节角度，在排球扣球后的着陆阶段，踝关节角度与髋关节和膝关节角度之间的关系是什么？
方法：在涉及外周疲劳方案的条件下，对28名年龄在19至28岁之间的职业男子排球运动员进行了扣球着陆后的下肢关节角度测量，他在诱发疲劳之前和之后都执行了Bosco疲劳协议。使用配对t检验来比较优势腿和非优势腿疲劳前后的关节角度。此外，进行Pearson相关性检验，以探讨IC处踝关节角度与相应的膝关节和髋关节角度之间的关系。
结果：研究结果显示，在优势和非优势腿中，疲劳显著增加了髋关节外旋，降低了膝关节的屈曲和外旋（p<0.05）。此外,相关分析表明，踝关节在正面和水平面的定位与髋关节屈曲和外旋在IC显著相关，以及膝关节屈曲和旋转（0.40结论：疲劳增加了髋关节外旋和踝关节内旋，削弱这些关节之间的相关性，同时加强踝膝关系，表明在跳跃中髋关节控制减少。这表明，由于踝髋连接减弱，优势腿的ACL损伤风险增加，与非优势腿形成对比。
目的：疲劳在多大程度上影响下肢关节角度，在排球扣球后的着陆阶段，踝关节角度与髋关节和膝关节角度之间的关系是什么？
方法：在涉及外周疲劳方案的条件下，对28名年龄在19至28岁之间的职业男子排球运动员进行了扣球着陆后的下肢关节角度测量，他在诱发疲劳之前和之后都执行了Bosco疲劳协议。使用配对t检验来比较优势腿和非优势腿疲劳前后的关节角度。此外，进行Pearson相关性检验，以探讨IC处踝关节角度与相应的膝关节和髋关节角度之间的关系。
结果：研究结果显示，在优势和非优势腿中，疲劳显著增加了髋关节外旋，降低了膝关节的屈曲和外旋（p<0.05）。此外,相关分析表明，踝关节在正面和水平面的定位与髋关节屈曲和外旋在IC显著相关，以及膝关节屈曲和旋转（0.40
