旋转关节

A three-dimension FEM model of normal L4-5 was built, and the lumbar facet joints were treated as to contact with each other. Various motions of L4-5 were simulated by changing the loads: anteflexion, retroversion, right rotation, right bending and longitudinal compression.

本文建立了L4-5正常运动节段的有限元模型，将两小关节面处理为接触模型，分析了小关节面在腰椎前屈、后伸、侧弯、旋转及压缩运动状态下的受力情况，发现小关节在承载方面作用较大，特别是抗旋转运动过程中作用更明显。

RESULTS:In vertebral pulp extirpation group, the stress was proved to be the highest at superior edge, posterior middle part, lower edge and anterior middle part of small joints under anteflexion, backward extension, compression, lateroflexion and revolving states, moreover, small joint stress in artificial lumbar intervertebral disk was higher than that in normal intervertebral disk, but obviously lower than that in vertebral pulp extirpation group;however, the small joint of the middle part of artificial lumbar intervertebral disk bore the highest stress under revolving states.

结果：髓核摘除组小关节的上边缘部、后中部、下边缘部和前中部在前屈、后伸、压缩、侧屈、旋转状态应力最大，人工腰椎间盘组的小关节的应力比正常椎间盘高，但明显小于髓核摘除组，但正中部在旋转状态下，人工腰椎间盘小关节的中心部位承受的应力最大。

Afterwards, we propose a new constant coefficients measurement method in dynamic equation of robot manipulators, this measurement method includes three groups of experiments: group one, let each joint of robot manipulator keep static to measure the constant coefficients in gravity term of dynamic equation and Coulomb frictional torque, group two: let only one joint of robot manipulator move at a constant velocity to measure the viscous frictional coefficient and constant coefficients in effective inertia of dynamic equation, group three: let only one joint of robot manipulator move at constant acceleration at a time to measure constant coefficients in Coriolis and centrifugal term and coupling inertia of dynamic equation.

让操作器单个关节恒速运动，在对驱动系统中传动机构，减速装置和电感系数综合考虑的基础上，这组实验对粘滞摩擦系数及有效惯量中常数系数进行测量。这种测量方法只要求旋转关节的驱动电机施加恒定电压，回转关节驱动电机施加正弦波电压。3。让操作器单个关节恒加速运动，这组实验测量动力学方程中哥氏力、离心力项和耦合惯量项中的常数系数，这种测量方法只要求单个关节匀加速运动，而其它各关节保持静止，这种测量方法虽然要求关节匀加速运动，但不必进行关节角加速度检测，而只需进行关节角位移和角速度检测即可，输入量直接给定为输入电压。

Facet joints oriented parallel to the sagittal plane provide substantial resistance to axial rotation but minimal resistance to shearing forces, whereas joints oriented more in a coronal plane tend to protect against flexion and shearing forces but provide minimal protection against rotation fig.

小关节朝向趋于矢状位可以限制脊柱的轴向旋转但是减少了对剪应力的限制。而趋于水平的小关节可以更好的保护屈曲和剪切下的应力，但对旋转的抵抗力降低（图3）。

In this paper a space mechanical robot arm, has 3 revolving joints, is designed according to the requirement.

本文针对这一设计要求，设计了具有三个旋转关节的空间机械机器人手臂。

There may be varying degrees of posterior element fracture and comminution of the spinous process, lamina, and lateral masses in association with burst, sagittal and/or coronal fractures of the vertebral body leading to the "so-called" teardrop fracture.

它或者发生于纯粹的平移，或围绕单个完整小关节的旋转平移（如单侧小关节的骨折或脱位）。进行亚分类的基本特征和区分平移或旋转损伤在于骨折是否累及了椎体，以及神经系统损伤的表现、严重性和残余的压迫症状。

Methods: 28 patients with isolated patellofemoral complications after total knee arthroplasty were scaned by computed tomography. The epicondylar axis and tibial tubercle were used as references to measure rotational alignment of the femoral and tibial components.

28例施行人工全膝关节置换术后出现单纯髌股关节并发症的患者进行膝关节轴位CT扫描，选择股骨髁上轴和胫骨结节作为CT扫描的参考标志来测量股骨假体和胫骨假体的旋转角度，分析旋转稳定性与髌股关节并发症的相关性。

There are more than two dozen reported cases of lumbar facet dislocation after rapid deceleration injuries (e.g., traffic accidents), most involving L5 S1.61,112 115 The mechanism of injury in these cases is purported to be a combination of hyperflexion, distraction, and rotation.61,112,116 In a posthumous study conducted in 31 lumbar spines of subjects who died of traumatic injuries,Twomey et al.117 found occult bony fractures in the superior articular process or subchondral bone plate in 35% of victims, and z-joint capsular and/or articular cartilage damage in 77% of cases.

多项研究报道了急性减速伤后发生腰椎小关节分离，多数发生于L5-S1，其机制可能为过度屈曲，分离和旋转。在一项对死亡病例的研究中，Twomey 等发现，31例因交通事故死亡的人中有35%的腰椎上关节突或软骨下骨性终板存在隐匿骨折，77%存在小关节囊和/或关节软骨损伤。作者总结创伤后隐匿性股和软组织损伤也许是腰痛的来源。

Secondly, the transfer joint, revolute joint and the transmission part are designed.

设计内容包括机械手的移动关节、旋转关节的结构设计，传动部分的设计等。

In prior art, the position and attitude control for antenna can only realized in small-scale, and lies in the means of hydraulic cylinder, gear box and rotary joint.

目前天线的位姿控制还都在小范围内实现，实现的手段是通过液压缸、齿轮箱和旋转关节等刚性结构的运动。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷