Thompson Rosemary E, Barker Timothy M, Pearcy Mark J
School of Mechanical, Manufacturing and Medical Engineering, Queensland University of Technology, GPO Box 2434, Qld 4001, Brisbane, Australia.
Clin Biomech (Bristol). 2003 Feb;18(2):89-98. doi: 10.1016/s0268-0033(02)00180-8.
To make an experimental assessment of the Neutral Zone of intervertebral joints during dynamic spinal motion in flexion/extension, lateral bending and axial rotation and to develop a criterion for its definition.
Dynamic mechanical testing of sheep intervertebral joints with a six-degree of freedom robotic facility under position control.
The Neutral Zone is defined as a region of no or little resistance to motion in the middle of an intervertebral joint's range of movement. Previous studies have used quasi-static loading regimes that do not model physiological activity. This study simulated physiological movements using a robotic testing facility to address this issue.
Five spines from mature sheep were used and three motion segments were tested from each spine. The robotic facility enabled the testing regime to be defined for each individual joint based on its geometry. The joints were tested by cycling through the full range of physiological movement in flexion/extension, lateral bending and axial rotation.
A Neutral Zone was found to exist during dynamic movements only in flexion/extension. The results suggested that a Neutral Zone does not exist in lateral bending or axial rotation. The zygapophysial joints were shown to be significant in determining the mechanics of the intervertebral joints as their removal increased the Neutral Zone in all cases. A new criterion for defining the size of the Neutral Zone during dynamic motion was proposed and its implications for spinal movements in life discussed.
A Neutral Zone exists in flexion/extension during dynamic movements of intervertebral joints and is a feature of the natural range of joint motion. This has important implications for the muscular control of the spine consisting of several intrinsically lax joints stacked on one another.
The existence of a Neutral Zone is a feature of the natural range of joint motion and requires complex control of intervertebral joints by the spinal muscles. Defining the biomechanical response throughout the physiological range of motion (RoM) is important in understanding possible injury and rehabilitation mechanisms.
对脊柱在屈伸、侧屈和轴向旋转动态运动过程中椎间关节的中性区进行实验评估，并制定其定义标准。
使用六自由度机器人设备在位置控制下对绵羊椎间关节进行动态力学测试。
中性区被定义为椎间关节运动范围内对运动无阻力或阻力很小的区域。以往研究采用的准静态加载方式无法模拟生理活动。本研究使用机器人测试设备模拟生理运动以解决这一问题。
使用来自成年绵羊的5个脊柱，每个脊柱测试3个运动节段。机器人设备能够根据每个关节的几何形状定义测试方案。通过在屈伸、侧屈和轴向旋转的整个生理运动范围内循环测试关节。
仅在屈伸动态运动过程中发现存在中性区。结果表明在侧屈或轴向旋转中不存在中性区。关节突关节在确定椎间关节力学方面具有重要作用，因为去除关节突关节在所有情况下都会增加中性区。提出了动态运动过程中定义中性区大小的新标准，并讨论了其对生活中脊柱运动的影响。
椎间关节动态运动过程中屈伸时存在中性区，这是关节自然运动范围的一个特征。这对由多个相互堆叠的本质上松弛的关节组成的脊柱肌肉控制具有重要意义。
中性区的存在是关节自然运动范围的一个特征，需要脊柱肌肉对椎间关节进行复杂控制。定义整个生理运动范围（RoM）内的生物力学反应对于理解可能的损伤和康复机制很重要。
