【作者】 鲍春雨；

【导师】 刘晋浩；

【作者基本信息】 东北林业大学 ， 森林工程， 2009， 博士

【摘要】 目前林业作业环境十分恶劣,操作者除了完成必须的操控任务外,还必须克服长时间站立、持较重工具、保持长时间弯腰姿势以及机器所产生的振动、噪声等的影响,这不仅会造成作业工人舒适性及工作效率下降,而且直接影响到他们的身心健康。许多工人因腰痛被迫离开工作岗位,因腰部损伤造成的经济损失和劳动力丧失非常严重。为此,运用精确的、可靠的测量工具和理论方法学研究脊柱生物力学特性进而采取有效的措施预防和减少与林业作业相关的脊柱损伤的发生,已成为国内乃至国际林业专家研究的重要课题之一。因此,开展基于人机工程学的作业负荷与人体生物力学特性研究具有重要的现实意义。本文采用多机同步技术,将肌电学与三维影像学相结合,探讨与分析了油锯作业姿势中人体躯干各肌肉的活动与功能;利用静力学原理建立了油锯作业姿势下人体脊柱生物力学模型;基于有限元法建立了完整脊柱三维数字化模型,并以腰椎节段为主要研究对象,对油锯作业姿势中人体脊柱受力特点进行了分析。研究结果如下:在不同作业工况中,躯干不同肌肉的工作强度存在差异,背部竖脊肌工作强度为最大,均在最大用力的30%左右,其次为腹直肌与腹外斜肌均在最大用力的10%左右。在不同作业工况下背部竖脊肌在整个操作过程中工作强度不尽相同,虽然在不同的作业工况下背部竖脊肌平均工作强度可能相近,但是在整个操作过程中,肌肉的用力程度是处于不同MVE%范围内的,且在整个操作过程中肌肉在不同的MVE%范围内所持续时间不同。在对不同地势与不同油锯对躯干各肌肉活动影响进行分析时发现,不同地势只对背部竖脊肌肌肉活动有影响(p＜0.05),而对其他肌肉活动影响无统计学意义。不同油锯对背部竖脊肌肌肉活动影响非常显著(p＜0.01),对右腹直肌和右腹外斜肌肌肉活动也有一定影响(p＜0.05)。在对使用矮把油锯打枝、造材和伐木动作进行分析发现,油锯作业时不同姿态下除左右腹外斜肌肌肉活动差异显著性水平在p＜0.05,其余各肌肉活动差异都存在显著性差异p＜0.01,说明不同的作业姿势对躯干各肌肉活动的影响存在显著性差异。首次将三维运动影像解析技术用于林业作业中,采用立体定机摄影原理,通过三维影像解析,确定了油锯作业不同姿势下躯干及上肢关节角度的活动范围值,对于正确规范林业操作姿势提供了理论依据。利用静力学原理,建立了不同油锯作业姿势下人体脊柱腰椎节段的生物力学模型,分析了人体脊柱腰椎各节段的力学特性;研究发现腰部所受重力矩、竖脊肌肌力、各腰椎节段椎体与椎间盘挤压力由小到大依次为油锯打枝(矮把)、高把油锯伐木、油锯造材(矮把)、矮把油锯伐木、提矮把油锯动作和提高把油锯动作。运用“组装搭配式”建模思想,结合DICOM数据,建立了具有几何非线性、材料非线性和接触非线性的完整人体脊柱三维有限元模型。并将有限元理论与林业作业姿势相结合,综合运用人体测量学、运动学、静力学等分析结果,对不同油锯作业姿势下腰椎节段的受力特点进行了计算机仿真。研究发现,相同油锯作业姿势中,椎体与椎间盘应力表现为由上至下呈逐渐增大趋势。不同作业工况下相同腰椎功能单位最大应力值表现为,打枝动作应力值最小、其后由小到大依次为:高把油锯伐木、矮把油锯造材、矮把油锯伐木、提矮把油锯动作,提高把油锯动作。本研究为确定不同林业操作中劳动工人腰背部肌肉工作强度提供理论参考,为定量研究在不同林业作业中操作工人的腰背部肌肉及脊柱所承担的工作负荷以及劳动强度理论依据,并对于预防和降低林业作业工人腰部损伤、提供劳动安全与保护、诊断和矫正不良作业姿势、进行劳动技能培训、指导设计与改进林业生产工具、职业病的预防与治疗等具有重要的理论价值。更多还原

【Abstract】 The forest work condition is very terrible in China at present.Apart from necessary operation,the operator also needs to bear the impacts of standing or bending for a long time, carrying heavy tools and vibration and noise of machines.All these impacts will decrease the comfort and efficiency of the operator and affect his physical and mental health.Many workers were compelled to quit their jobs because of lumbar back pain,which suffered serious economic expense and loss of labor ability due to lumbar trauma.Consequently,it is necessary to reduce social burdens due to spine trauma.And accurate and credible measurement tools and research of theoretical methodology can make us understand biomechanical characteristic of spine better.Furthermore,we can adopt effectual measures to prevent and decrease the spine trauma related to forestry work,it is one of important studies for the experts in home and abroad.Thus it is most realistic significant to carry out labor burdens and human body biomechanics based on ergonomics.The paper discussed and analyzed the trunk muscles activities and functions from angle of view of surface electromyography and three-dimensional photogrammetry by applying external synchronization technology for the first time,and established the biomechanical models under different forestry work postures using the chain saws by statics theory,the three-dimensional digital model of spine were established based on finite element method.The thesis studied the biomechanical characteristic under different operating postures using chain saws,the lumbar as object.The results were showed as following:The work intensity of trunk muscles activities was different in forestry work conditions; work intensity of Erector spinae were the maximum,approaching over 30%Maximum Voluntary Contraction(MVC),and EMG amplitudes of Rectus abdominis and Oblique external abdominis were 10%MVC.Under different forestry work conditions,the EMG amplitudes of Erector spinae were not at the same level in the process of forestry operating,although the average intensity of Erector spinae was probably identical under different forestry work conditions,the EMG amplitudes of Erector spinae distribute in different ranges of MVE%,and the duration spent in the certain ranges of MVE%is not same in the process of entire operating.The thesis analyzed the influence of terrains and chain saws on the trunk muscles.The results showed that the terrains only influenced the Erector spinae amplitudes(p＜0.05),while it makes no sense to study the the influence of terrains on other muscles amplitudes.The influence of chain saws on the Erector spinae was very significant(p＜0.01),and influence on the right Rectus abdominis and right Oblique external abdominis(p＜0.05).The thesis analyzed limbing,bucking and cutting operation by using chain saw type G621AVS.The results show that difference of the EMG activities among trunk muscles were distinct(p＜0.01),while Oblique external abdominis amplitudes(p＜0.05).These facts indicated that different forestry work postures were the primary influence on EMG activities among trunk muscles.The three-dimensional motion photogrammetry system was used in forestry work for the first time,photography principle of stable location of vidicon is adopted,and the motion ranges of joint angle for the trunk and upper limbs were defined under different forestry work postures, which provided theoretical reference to correct the forestry operating postures.The biomechanical models of lumbar spine under different forestry operating postures were established and calculated the solutions by statics principle,in order to study the biomechanical character of lumbar spine.The results showed that the gravity moment of lumbar spine,power of Erector spinae and compressive stress on the vertebral body and intervertebral disc were as follows in increasing sequence,limbing(G621AVS),cutting(GJ85), cutting(G621AVS),bucking(G621AVS),lifting chain saw(G621AVS and GJ85).The three-dimensional,comprehensive and realistic finite element model of whole spine that incorporated the geometric,material and contact non-linearities was established through using the datum of DICOM based on opinion of "assembled construction".The finite element theory and forestry work postures were combined together,and features of stress of lumbar spine under different forestry work postures were computed by taking advantage of the results of anthropometry,kinematics and statics.The results are as follows:Equivalent stress on the vertebral body and intervertebral disc had a trend of gradual increase from bottom to top under the same forestry work condition.The maximum tress on the same lumbar functional unit under different forestry work conditions were showed from low to high:limbing(G621AVS), cutting(G621AVS),bucking(G621AVS),cutting(GJ85),lifting chain saw of type G621AVS and GJ85.The research can provide theoretical reference to ascertain work intensities of Erector spinae for forestry worker under different forestry work conditions,which has important theoretical value to quantificationally study loads and labor intensities of the lumbar muscles for the forestry workers under different forestry work conditions,to prevent and decrease the lumbar traumas,to provide laboring safety and protection,to diagnose and correct unreasonable operating postures,to train the labor skills,to design and improve forest operating tools,to prevent and treat the occupational diseases.更多还原