【作者】 徐红旗；

【导师】 王安利；

【作者基本信息】 北京体育大学 ， 运动人体科学， 2011， 博士

【摘要】 目的：本研究拟对青年人重复性地面至站立位指间关节高度提举能力测试的同时,对其背部与下肢仲肌表面肌电信号及机体生物力学机制变化特征进行监控,并建立推算各关节受力变化的仿真模型,以探讨提举操作的运动学与动力学机理；结合个体差异分析重复性提举能力的影响因素；明确不同提举姿势优劣点,优化提举技术方法：40名男大学生,测量其身体形态,右下肢三关节仲肌等长峰值肌力、等张极限功率与肌耐力。BTE系统与sEMG仪,运动分析系统与测力台同步,受试者进行两次重复性提举能力测试,尽力持续至疲劳；频率12次／min,木箱(35cm×25cm×25cm)重13kg,蹲举与半蹲举交叉进行,间歇30min；并记录sEMG,测量安静心率、两次测试结束即刻心率与不适程度自我评分、休息28min后心率。在重复性提举能力测试前后,受试者两手间隔35cm,提柄约与膝高,两脚开立约与肩宽；进行每组3次持续6s间歇15s的最大腰拉力测试,并记录sEMG。结果：重复性提举能力测试表明,输出总功、功率、提举次数、持续时间等参数蹲举高于半蹲举；以输出总功为应变量的多元回归分析表明伸膝肌力与肌耐力及最大腰拉力是两提举姿势的共有正向变量。IMDF变化表明蹲举上背、下背与大腿部,半蹲举下背与小腿部有疲劳积累。MDF与MNF变化表明下背与大腿部有疲劳积累。两姿势下,躯干与四肢关节承受合力与压力峰值从大至小的顺序皆为腰骶—下肢—上肢—颈7；承受切力峰值以踝、膝、骶1最为明显；承受不平衡力峰值半蹲举以腰骶部最大,蹲举以下肢部最大,其次是上肢与颈7。躯干与四肢承受合力与压力峰值(除腕部)半蹲举小于蹲举；四肢不平衡力与切力峰值(除腕部)半蹲举小于蹲举,腰骶部半蹲举大于蹲举。两姿势下,腰骶部由上至下承受压力、合力峰值依次增加,不平衡力峰值有所减少；切力峰值蹲举在减小而半蹲举在增大；且相对安全限值,半蹲举切力峰值的增大要高于蹲举压力峰值的增大。结论：伸膝肌力与肌耐力及最大腰拉力是两提举姿势下重复性提举能力的共有正面影响因素。两姿势下,躯干与下肢受力皆高于上肢；身体承受合力、压力半蹲举小于蹲举；四肢不平衡力与切力半蹲举小于蹲举,腰骶部半蹲举大于蹲举。两姿势下,腰骶部由上至下承受压力、合力依次增加,不平衡力有所减少；但切力蹲举在减小而半蹲举在增大。与半蹲举相比,蹲举是一种优势的手工提举技术。更多还原

【Abstract】 Objective:This research was to test the repetitive lifting capacity from floor to knuckle height of the youth, at the same time, monitor the muscle sEMG of back and lower limbs, and the biomechanical mechanism variation of body, create the simulation model that can calculate the changed force on the joints, discuss the mechanism kinematics and dynamics of repetitive lifting, analysis the influence factors of repetitive lifting together with the individual differences, identify the advantages and disadvantages of different lifting posture, optimize the lifting technique.Methods:A total of 40 male university students was tested their body shape, the isometric peak torque, isotonic power and endurance of the right lower limb extension muscles in hip, knee, ankle joint. BTE system and sEMG instrument, motion analysis system and force platform were synchronized, the subjects repeated twice the test of repetitive lifting capacity, tried to continue until fatigue; The lifting frequency was 12 times/min, wooden box(35cm×25cm×25cm) was 13kg, undertaken squat and semi-squat by turns,30min interval of time; and recorded sEMG, measured the resting heart rate, twice immediate heart rate after the test of repetitive lifting capacity and the discomfort self-ratings, the resting heart rate after 28min. Before and after the test of repetitive lifting capacity, the subjects hands separated 35cm, handle was about the height of knee, two feet separated equal to the width of shoulder; repeated two sets the maximum torso pull, each set was 3 times, continues 6s,15min interval of time, and recorded sEMG.Results:The test of repetitive lifting capacity indicated the parameters of squat better than semi-squat in total work output, power, lifting times and duration; Total work output as the dependent variable, the multiple regression analysis showed that the strength and muscular endurance of knee extensor muscle and the maximum torso pull were the conjunct positive independent variable for two lifting posture. IMDF change showed that the local muscle fatigue accumulation appeared at the upper back, lower back and thigh under the squat, the lower back and leg under the semi-squat. MDF and MNF change showed that the local muscle fatigue accumulation appeared at the lower back and thigh.Two lifting posture, The peak resultant force and pressure of trunk and limbs from large to small is lumbosacral-lower limbs-upper limbs-C7; The ankle, knee and S1 were the most obvious position for the peak shear force; the lumbosacral under the semi-squat and the lower limbs under the squat were the most obvious position for the peak unbalanced force, followed by the upper limbs and C7. The peak resultant force and pressure of trunk and limbs (except the wrist) under the semi-squat were less than under the squat; The peak unbalanced and shear force of limbs (except the wrist) under the semi-squat were less than under the squat, the lumbosacral under the semi-squat were larger than under the squat. Two lifting posture, the peak resultant force and pressure of the lumbosacral increased by turns from top to bottom, the peak unbalanced force decreased to some extent; the peak shear force decreased under the squat and increased under the semi-squat; And relatively safe limits, the peak shear force increased under the semi-squat was larger than the peak pressure force increased under the squat.Conclusion:The strength and muscular endurance of knee extensor muscle and the maximum torso pull were conjunct positive influencing factor for the repetitive lifting capacity under two lifting posture. Two lifting posture, the force of trunk and limbs were larger than upper limbs; the resultant force and pressure of body under the semi-squat were less than under the squat; the unbalanced and shear force of limbs under the semi-squat were less than under the squat, the lumbosacral under the semi-squat were larger than under the squat. Two lifting posture, the resultant force and pressure of lumbosacral increased by turns from top to bottom, the unbalanced force decreased to some extent; the shear force decreased under the squat and increased under the semi-squat. Compared with the semi-squat, squat is a predominant manual lifting technique.更多还原