基于实时超声探究跑姿对内侧腓肠肌-肌腱复合体形态学和力学特性的即刻影响  

Acute Effect of Foot Strike Pattern on the Morphological and Mechanical Properties of Medial Gastrocnemius-Tendon Unit Based on Real Time Ultrasound

作　　者：邓力勤 张希妮 肖松林 王宝峰 武楷承 张胜年 傅维杰 DENG Liqin;ZHANG Xini;XIAO Songlin;WANG Baofeng;WU Kaicheng;ZHANG Shengnian;FU Weijie(Key Laboratory of Exercise and Health Sciences of Ministry of Education,Shanghai University of Sport,Shanghai 200438,China)

机构地区：[1]上海体育大学运动健身科技省部共建教育部重点实验室,上海200438

出　　处：《上海体育学院学报》2023年第9期75-84,共10页Journal of Shanghai University of Sport

基　　金：国家自然科学基金面上项目(12272238);第六批上海市青年拔尖人才开发计划。

摘　　要：目的探究前掌着地跑(forefoot strike pattern,FFS)和后跟着地跑(rearfoot strike pattern,RFS)时内侧腓肠肌-肌腱复合体(medial gastrocnemius-tendon unit,MTU)形态学及力学特性的差异。方法招募15名习惯RFS男性跑者,着统一跑鞋以9 km/h的速度完成RFS或FFS下的跑步测试。采用超声、运动捕捉系统和测力跑台实时采集跑步内侧腓肠肌(medial gastrocnemius,MG)影像和地面反作用力等,并计算触地角度,分析MG/MTU形态学和力学特性。结果与RFS相比,FFS时:①地面反作用力蹬伸峰值显著更大;②MG支撑期收缩量/率和蹬伸期收缩率显著更小;③峰值MG收缩速度显著更小,峰值肌力显著更大;④MTU收缩速度和功率、拉伸量、拉伸速度和功率显著更大。结论在同跑速下习惯RFS跑者转换成FFS后即刻局部优化了MTU特性,即MG以更少的收缩量产生更大力量且MTU能储存和释放更多能量,提高了肌肉收缩和蹬伸效率。Objective To explore the effects of foot strike pattern on the morphological and mechanical properties of medial gastrocnemius-tendon unit(MTU).Methods Fifteen healthy recreational runners with habitual rearfoot strike pattern(RFS)were recruited to run at 9 km/h wearing cushioned shoes with RFS and forefoot strike pattern(FFS).An ultrasound system,motion capture system and the instrumented treadmill were utilized to capture the ultrasound image of medial gastrocnemius(MG)in-real,and the ground reaction force(GRF)during running.The foot strike angle,and morphological and mechanical properties of the MG/MTU were calculated.Results Compared with RFS,FFS runners exhibited:①greater second peak GRF;②lower MG shortening length/rate during stance phase and shortening rate during toe-off phase;③lower peak shortening speed and higher MG force;④greater MTU shortening speed/rate,lengthening and shortening length,speed and power.Conclusion It was confirmed that habitual RFS runners had acute partial optimization effect of MTU.Specifically,the MG could produce more force with less muscle contraction,and the MTU could store and release greater energy at the same running speed,thereby improving the efficiency of MG contraction and propulsion efficiency after an acute switch to FFS.

关 键 词：内侧腓肠肌 肌腱 跑姿 形态学 力学特性 肌肉收缩 蹬伸效率 

分 类 号：G804.6[文化科学—运动人体科学]