【作者】 井兰香；

【导师】 刘宇；

【作者基本信息】 上海体育学院 ， 运动人体科学， 2009， 博士

【摘要】 研究目的:测试不同负重原地垂直纵跳下肢动力学、运动学以及肌电数据,比较下肢关节动力学、关节贡献度及拮抗肌共激活,确定超等长训练提高下肢肌肉力量和爆发力的最佳负重;测试不同负重半蹲跳下肢动力学、运动学以及肌电数据,比较关节贡献度和拮抗肌共激活,明确不同负重对半蹲跳动作下肢动力学及肌肉活性的影响;测试不同高度跳深下肢动力学和肌电数据,比较下肢肌肉预激活,确定最佳下落高度。在上述研究基础上,观察负重超等长训练对下肢肌最大肌肉力量及下肢爆发力的影响;比较负重超等长训练前后下肢动力学及下肢各关节动力学参数变化,比较负重超等长训练前后下肢拮抗肌共激活和预激活水平的变化,揭示负重超等长训练提高下肢肌肉力量和爆发力的机制。本研究的意义在于:为篮球运动员提高下肢肌肉力量和爆发力选择适宜的训练模式提供可靠的实验数据;为负重超等长训练模式的推广和负重超等长训练器械的实践应用提供基础性的理论依据;为教练员制定合理的训练计划提供实际指导原则。研究方法:利用负重超等长训练器械,对16名男性篮球运动员进行下肢超等长训练。首先测得下肢肌肉一次最大反复值(one repetition maximum, 1RM),算出每个受试者0、10、20、30、40、50、60%1RM作为不同负重条件。下肢动力学数据由KISTLER-3D测力台采集,采样频率为1200Hz。下肢运动学数据使用VICON系统采集,采样频率为120Hz,八个红外摄像头感应标记于左侧髂结节、髂前上棘、大转子、膝关节内上髁、膝关节外上髁、内踝、外踝、第一跖指关节、第五跖指关节、脚尖的感光球,VISUAL3D图像分析系统重建三维坐标进行后期数据处理;采用标准逆向动力学方法计算下肢净关节力矩。根据弹簧-质量模型计算下肢刚度和下肢各关节刚度。与运动学、动力学数据同步采集的下肢肌肉肌电信号数据,由八通道表面肌电信号采集系统完成,参数为增益1000,共模抑制比12dB,采样频率为1200Hz。表面电极粘贴于胫骨前肌、腓肠肌外侧头、股直肌、股外侧肌、股二头肌的肌腹处皮肤表面,以胫骨粗隆位置作为0电极。DASYLab8.0肌电信号分析系统进行后期数据处理,计算所测试的每块肌肉的积分肌电值,计算股直肌/股二头肌,腓肠肌外侧头/股外侧肌,胫骨前肌/腓肠肌外侧头三对拮抗肌/主动肌共激活。.研究结果:(1)超等长训练动作下肢动力学分析结果表明:负重超等长训练动作下肢髋关节贡献度最大,膝关节贡献度最小。(2)负重超等长训练前后下肢动力学比较结果表明:原地垂直纵跳向心阶段峰值地面反作用力和1RM值显著提高;半蹲跳向心阶段冲量显著增加;髋、踝关节峰值净关节力矩和峰值关节功率显著提高,膝关节峰值力矩和峰值功率不受训练影响;下肢刚度和髋、踝关节刚度显著提高。负重超等长训练前后肌肉活性比较结果表明:髋、踝关节拮抗肌共激活水平显著降低,预激活水平显著提高。主要结论:(1)负重超等长训练动作过程髋关节、踝关节贡献度大于膝关节贡献度,说明负重超等长训练对髋、踝关节要求程度大于对膝关节的要求,提示此种训练方式髋、踝关节所起的作用大于膝关节,主要发展髋、踝关节肌肉力量和爆发力。(2)负重超等长训练能显著提高髋、踝关节峰值力矩、峰值关节功率、关节刚度,说明下肢肌肉力量和爆发力的提高主要通过髋、踝关节肌肉动力学提高实现,继而能提高下肢弹跳力和运动速度。负重超等长训练显著降低髋、踝关节拮抗肌共激活,提高预激活,说明负重超等长训练提高了神经肌肉适应能力,提高了肌肉之间协调性,提高了下肢多关节运动能力。(3)综合下肢动力学和肌肉活性分析,负重超等长训练是有效的提高下肢肌肉力量和爆发力的训练模式,适用于对弹跳力和速度要求较高的运动项目。更多还原

【Abstract】 Purpose: The purpose of this study was to compare the joint kinetics, joint contributions and co-activation of lower extremity during countermovement jump and identify the optimal loading when one wanted to promote lower extremity strength and power during plyometric weight training. We measured kinetics, kinematics and electromyogram data of lower extremity. We measured the same data during squat jump with different loads in order to clarify the effects of loads on kinetics, kinematics and muscle activity of lower extremity. Furthermore, in order to compare the pre-activation and determine the optimal drop height we measured kinetics and electromyogram data of lower extremity during drop jump with different height. Based on the above-mentioned context, we attempt to observe the effects of plyometric weight training on maximum muscle strength and power of lower extremity, to reveal the mechanism that how the muscle strength and power of lower extremity are promoted after plyometric weight training. So we compared the lower extremity kinetics, joint kinetics, co-activation and pre-activation pre-/post-training.The sense of this study was to provide reliable experimental data for athletes to select appropriate training mode in promoting lower extremity strength and power, to provide fundamental theory for spreading of plyometric weight training and practicing of plyometric weight training machine, and to provide practicing principles for coaches to make rational plans for training.Methods: Sixteen male basketball athletes were trained their lower extremities with plyometric training with the help of plyometric weight training machine. Initially, a 1-repetition maximum squat (1RM) resistance was determined for each subject and then the 0, 10, 20, 30, 40, 50, 60%1RM of each subject was calculated as different loading conditions. A KISTLER-3D force plate was used to collect kinetics data of lower extremity with a sampling rate of 1200Hz. Kinematic data of lower extremity were acquired using a VICON motion analysis system consisting of eight infra-red ray cameras with a sampling rate of 120Hz to detect the motion of reflective markers placed on skin over the left tubercle of iliac crest, anterior superior iliac spine, greater trochanter, medial and lateral epicondyle of knee, medial and lateral malleolus, first and fifth metatarsophalangeal joint, tiptoe. VISUAL3D image analysis system was used to reconstruct the marker 3D co-ordinates for data processing. Standard inverse dynamic calculations were used to determine the net joint moment. Leg stiffness and joint stiffness of hip, knee, and ankle were calculated using spring-mass model. An eight channel surface electromyogram was used to collect the electromyogram signal data of lower extremity synchronously with kinetics and kinematics data. The Gain was 1000, Common Mode Reaction Ratio was 12 dB and sampling rate was 1200Hz. Bipolar surface electrodes were placed over the muscle belly of the tibialis anterior, gastrocnemius lateralis, rectus femoris, vestus lateralis, and biceps femoris, 0 electrode on tibial tuberosity. DASYLab8.0 electromyographic signal analysis system was used for data processing after which the integrated electromyographic of each muscle and co-activation of rectus femoris/biceps femoris, gastrocnemius lateralis/vestus lateralis, and tibialis anterior/gastrocnemius lateralis were calculated.Results: (1) The analysis of lower extremity dynamics indicated that hip was the dominate contributor and knee is the least during plyometric weight training. (2) The comparison of lower extremity dynamics pre-/post- plyometric weight training indicated that the peak vertical ground reaction force and 1RM during concentric phase of countermovement jump, the impulse of concentric phase of squat jump, peak net joint moment and peak net joint moment power of hip and ankle during concentric phase of countermovement jump were significantly promoted. But the peak net joint moment and peak net joint moment power of knee were not influenced by this training. Leg stiffness and joint stiffness of hip and ankle were also significantly increased after plyometric weight training. The comparison of lower extremity muscle activity of pre-/post- plyometric weight training indicated that co-activations of hip and ankle significantly decreased and pre-activation was significantly increased.Conclusion: (1) During plyometric weight training action the joint contributions of hip and ankle is greater than knee, which indicated more demand of hip and ankle than knee. The result suggested that the role of hip and ankle was more important than knee during this kind of training, thus the muscle strength and power of hip and knee were mainly developed. (2) The fact that the peak net joint moment, peak joint moment power, and joint stiffness were promoted after plyometric weight training indicated that muscle strength and power of lower extremity were elevated through the increasing of hip and ankle muscle joint dynamics, then, the bounce and velocity of lower extremity were promoted. The fact that the co-activation decreased and pre-activation increased after plyometric weight training indicated that the adaptability and concordant of muscle were promoted, and then multijoint motor capacity increased. (3) From the analysis of lower extremity dynamics and muscle activity we concluded that plyometric weight training is an effective training mode for promoting muscle strength and power of lower extremity. It is applicable to the projects that highly demand bounce and velocity.更多还原