Effects of Fatigue Intervention on Biomechanics of Lower Extremity during a Stretch-Shortening Cycle Movement
- VernacularTitle:疲劳干预对拉长-缩短周期动作中下肢生物力学的影响
- Author:
Xiaole SUN
1
;
Rui XIA
;
Xini ZHANG
;
Yang YANG
;
Weijie FU
Author Information
1. 上海体育学院运动健身科技省部共建教育部重点实验室 上海200438
- Keywords:
stretch-shortening cycle (SSC) movement;
drop jump;
fatigue;
stiffness;
joint work
- From:Chinese Journal of Sports Medicine
2018;37(1):19-27
- CountryChina
- Language:Chinese
-
Abstract:
Objectives To explore the effect of fatigue intervention on biomechanics of lower extremity and performance during the stretch-shortening cycle(SSC) movement-drop jumps(DJ).Methods The Vicon motion capture system and 3D Kistler force plates were used to collect sagittal plane kinematics and ground reaction force data synchronously of a total of fifteen trained male athletes under pre-and post-fatigue conditions with shuttle running + vertical jumping fatigue protocol.The joint angle,joint moment,power,work,and leg/joint stiffness were compared before and after fatigue.Results After fatigue,the maximum height of DJ decreased(P＜0.05),while the touchdown angle and the range of motion(△θ) of knee and ankle joints,as well as the occurrence time for the eccentric,concentric and total phase increased(P＜0.05).However,the maximum push-off moment and power of knee reduced(P＜ 0.05).The stiffness of knee and ankle joints during the eccentric phase reduced,resulting in the reduction of the leg stiffness(P＜0.05).Moreover,the energy absorption and net energy of the ankle joint decreased;meanwhile,the energy contribution of the knee joint decreased during the eccentric phase of a DJ task.Conclusion Fatigue changes the movement pattern,decreasing the control ability of the lower extremity especially in the knee and ankle joint,and results in decreased performance.Moreover,the decrease of leg,ankle and knee stiffness and the corresponding energy can be used as sensitive indexes to evaluate the performance of drop jumps in a fatigued condition.
