If the body is restricted to motion in a plane, there are three degrees-of-freedom: translation in two coordinate directions and rotation within the plane.
如果该机构是限制于在一个平面运动，那有三个自由度：直线运动在两个坐标方向和在平面内的旋转。
2
Radiographic examination included Cobb Angle, rotation Angle of apical vertebrae, and translation of the C7 vertebra from the center sacral line on the coronal plane.
线检查包括Cobb角，椎体顶点的旋转角和C7椎体在冠状面从骶正中线的平移。
3
World coordinate that had undergone some transform such as translation, and rotation was unified with display coordinate through 2D projection plane of 3D display coordinate.