疲労下におけるバドミントンランジ中の下肢関節運動学の機能的データ解析
Yuling Fang1, Xingchen Zhang1, Yang Sun1
1School of Physical Education, Yanshan University, Qinhuangdao, China.
Objective:
This study applied Functional Data Analysis (FDA) to investigate the effects of fatigue on lower-limb joint kinematics during badminton lunges.
Methods:
Seventeen elite male badminton players executed both forward and 45° sideways forehand lunges before and after a fatigue protocol. Three-dimensional kinematic data of the lower limbs were collected using a motion capture system synchronized with force plates. Functional principal component analysis (FPCA) was employed to reduce dimensionality and extract key features from the time-series curves of hip, knee, and ankle joint angles. Paired-samples t-tests were used to compare the principal component scores before and after the induction of fatigue.
Results:
Fatigue significantly altered lower-limb movement patterns. Sagittal-plane analyses revealed a decreased range of motion in hip and knee flexion, contrasted with an increased range of ankle dorsiflexion (p < 0.05). In the coronal plane, hip and knee abduction-adduction ranges decreased, while ankle inversion-eversion ranges increased (p < 0.05).
Conclusion:
Fatigue triggered a "top-down" compensatory response: proximal joints stiffened to stabilize, while the ankle enhanced flexibility to compensate. This "proximal-stiffening, distal-mobility" pattern maintained performance but may have redistributed loads, potentially raising the risk of ACL and lateral ankle ligament injuries. These findings help guide fatigue-specific training and injury-prevention strategies.
