Fig. 4From: The effect of various weight-bearing activities on the motion of lumbar facet joints in vivoa Establish a Cartesian coordinate system at the center of the vertebral body. b, c place the Cartesian coordinate system established above in the center of the joint capsule. α The range of rotation around the mid-lateral axes, β Rotation range around the anteroposterior axes, γ The range of rotation around the craniocaudal axisBack to article page