我国自由式滑雪空中技巧优秀运动员主要关节等速肌力特征

Research on Isokinetic Strength Characteristics of Major Joints of China Elite Freestyle Skiing Aerial Athletes

目的:对自由式滑雪空中技巧优秀运动员主要关节肌肉力量素质特征和规律进行分析,为专项体能训练以及制定青年运动员专项力量训练方法提供科学依据。方法:利用德国ISOMED2000等速肌力测试系统,对18名(男女各9名)优秀运动员髋、膝、踝关节和躯干力量进行测试。选取单位体重的峰值力矩PT/BW、屈/伸肌群比值H/Q和肌力下降率等为测试指标。按测试模式(向心、离心收缩)、测试速度(慢速、快速收缩)和测试侧别(左侧、右侧)分为3个因素,采用3因素(2×2×2)重复测量方差分析检验不同因素对髋、膝、踝关节和躯干力量的影响。结果:1)各因素的主效应均存在显著性差异(P<0.05),模式×速度在PT/BW指标上的交互作用也显著(P<0.05);2)髋关节:60°/s和180°/s时,屈肌群离心收缩力量和H/Q显著大于向心收缩(P<0.01);3)膝关节:在向心和离心收缩时,180°/s的H/Q均显著大于60°/s(P<0.01);4)踝关节:左侧快速背伸肌群的PT/BW显著大于右侧(P<0.01);5)躯干:60°/s向心收缩时的PT/BW显著大于180°/s(P<0.01);6)各关节肌力下降率特征为:膝关节>躯干>踝关节>髋关节。结论:1)空中技巧运动员主要关节肌力受收缩模式和速度的影响,模式对肌力的影响最大,速度次之。2)快速伸肌群肌力和快速离心力量是影响该项目的核心指标,在出台和落地缓冲过程中尤为重要。3)运动员主要关节屈伸肌群力量比较均衡;髋、膝关节左右侧肌力对称性较好,女子髋关节和躯干屈肌群肌力有待加强。4)运动员膝关节、躯干伸肌群快速力量下降率较高,训练中应注意防护。

Objective To explore the muscle strength characteristics of main joints of elite freestyle skiing aerial athletes,so as to provide a scientific basis for the special physical training for young athletes.Methods Eighteen elite freestyle skiing aerial athletes(9 males and 9 females)were tested their muscle strength of the trunk,hip,knee and ankle joints using the ISOMED2000 isokinetic strength measuring system.The peak torque per unit weight(PT/BW),hamstring/quadriceps ratio(H/Q)and decrease rate of muscle strength were selected as the test indicators.The three-way ANOVA(2×2×2)with repeated measures was used to analyze the effect of different factors on the muscle strength of the hip,knee,ankle and trunk during the concentric and eccentric contractions of the left and right side at low and high speed.Results(1)There were significant differences in the main effect of each factor(P<0.05),and the interacted effect between the contraction direction and speed(P<0.05).(2)As to hips,at 60°/s and 180°/s,the eccentric contraction strength and H/Q of the flexor group were significantly greater than those during the concentric contraction(P<0.01).(3)For knees,during the concentric and eccentric contraction,the average H/Q at 180°/s was significantly higher than at60°/s(P<0.01).(4)For ankles,the PT/BW of the left side of the fast dorsiflexion muscle was significantly higher than the right side(P<0.01).(5)For trunks,the PT/BW at 60°/s in the concentric contraction was significantly higher than at 180°/s(P<0.01).(6)The decrease rate of the muscle strength was the highest of the knee,followed by that of the trunk,ankle and hip.Conclusion(1)The muscle strength of major joints in freestyle skiing aerial athletes is affected by the direction and speed of contraction,with that of the direction significantly greater than the latter.(2)Fast extensor strength and fast eccentric strength are the coreaffecting indicators,particularly important in the taking off and landing process.(3)The muscle strength of major joints is relatively balanced,especially that of the hip and knee.However,the flexor muscle strength of hip joint and trunk of female athletes needs strengthening.(4)The decrease rate of fast extensor muscle strength of the knee joint and trunk is high,so we should pay attention to protection in training.