儿童下肢生物力学特征在视觉剥夺及双重任务时的变化  

Changes in biomechanical characteristics of children’s lower limbs during visual deprivation and dual tasks

作　　者：欧阳一毅 彭杰 王坤 张庭然 罗炯[3] Ouyang Yiyi;Peng Jie;Wang Kun;Zhang Tingran;Luo Jiong(Institute of Physical Education,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Institute of Physical Education,Liupanshui Normal University,Liupanshui 553000,Guizhou Province,China;Institute of Physical Education,Southwest University,Chongqing 400715,China)

机构地区：[1]重庆邮电大学体育学院,重庆市400065 [2]六盘水师范学院体育学院,贵州省六盘水市553000 [3]西南大学体育学院,重庆市400715

出　　处：《中国组织工程研究》2022年第12期1834-1842,共9页Chinese Journal of Tissue Engineering Research

基　　金：中央高校基金项目(SWU1809386),项目负责人:欧阳一毅。

摘　　要：背景:人体平衡与控制有赖于内耳前庭系统、本体感受器及视觉系统的协调及中枢神经系统等共同配合才能完成,但人在视觉剥夺或双重认知任务时会引发神经控制与感觉统合的变化,进而改变下肢平衡控制能力及动作控制策略。目的:探讨儿童在不同视觉输入及执行不同认知任务时下阶梯时下肢生物力学特征的变化规律,从而揭示其作用机制,为预防及减少儿童下阶梯时的跌倒伤害提供一些有益参考。方法:共招募20名西南大学附属小学3-6年级的小学生志愿者,每个年级5名。运用运动学(JVC9800高速摄像机)、动力学(BIOFORCEN动态平衡训练评估系统)及肌电(JE-TB0810八通道肌电测试仪)等测试工具,同步采集受试者在不同视觉输入及执行不同认知任务时下阶梯动作的生物力学参数。结果与结论:(1)闭眼及双重任务下阶梯着阶瞬间的膝、踝关节角度显著大于睁眼及单一任务时的角度(P<0.05),但在身体重心处于最低瞬间时仅踝关节角度展现出闭眼及双重任务下显著大于睁眼及单一任务(P<0.05);(2)睁眼及双重任务下的压力中心前后方向位移均方根、左右方向位移均方根、摆动的轨迹总长及轨迹包络面积皆显著小于闭眼时(P<0.05);(3)闭眼及双重任务下阶梯着阶前200 ms股二头肌、股直肌、胫骨前肌及内侧腓肠肌的平均肌电振幅标准化参数值和肌肉激活时长皆显著小于睁眼及单一任务(P<0.05);但在缓冲期仅胫骨前肌及内侧腓肠肌的平均肌电振幅标准化参数值展现出闭眼及双重任务下显著小于睁眼及单一任务的趋势(P<0.01);(4)提示视觉剥夺、双重任务下阶梯皆会阻碍中枢神经系统信息的传递,使得身体的预期姿势调节下降,影响下阶梯时下肢肌肉的预先激活状况,进而影响儿童对平衡的控制及步态稳定性,增加了儿童跌倒风险,但视觉剥夺对儿童平衡控制的影响显著高于双重任务;BACKGROUND:Human balance and control depend on the coordination of the inner ear vestibular system,proprioceptors and visual system,and the central nervous system.However,when a person is visually deprived or dual cognitive tasks,it will cause changes in neural control and sensory integration,and then change lower limb balance control ability and movement control strategy.OBJECTIVE:To explore the biomechanical changes of the legs in stair descendent of different visual inputs and cognitive tasks so as to reveal action mechanism,thus preventing and avoiding accidents of children falling off stairs in descending stairs.METHODS:Twenty students from grades 3-6 of the Primary School Attached to Southwest University were volunteered to participate in the research(n=5 for each grade).The biomechanical parameters of participants in stair descendent of different visual inputs and cognitive tasks were collected with such test tools as JVC9800 high-speed video camera of kinematics,BIOFORCEN dynamic balance training assessment system of dynamics,and JE-TB0810 eight-channel electromyogram tester of surface electromyography.RESULTS AND CONCLUSION:(1)The angle of the knee joint and the ankle joint with eyes closed and double tasks was obviously larger than that with eyes open and single task(P<0.05),while the center of gravity was in the lowest level,the angle of the ankle joint with eyes closed and double tasks was obviously larger than that with eyes open and single task(P<0.05).(2)The lengthways displacement root mean square of center of pressure,transverse displacement root mean square of center of pressure,length of swing trajectory of center of pressure and the enveloping surface of center of pressure with eyes open and double tasks were all smaller than those with eyes closed(P<0.05).(3)The average electromyogram amplitude standardization parameter and activation length of the biceps femoris,rectus femoris,tibialis anterior and medial head of gastrocnemius with eyes closed and double tasks were significantly smaller than

关 键 词：视觉剥夺 认知任务 运动学 平衡控制 肌电 

分 类 号：R459.9[医药卫生—治疗学] R318[医药卫生—临床医学]