Lie on the roller with your knees bent and your feet on the floor, so the roller extends along your spine from your sitting bones to the top of your head.
双膝弯曲，两脚着地，躺在这个滚筒上，让它沿着你的脊柱，一直从尾骨到头顶。
2
HEAD PULL : Green roller defect caused by improper machine timing; results in nick or indent of large end of radius.
端部撕扯：由于不正确的设备节奏而导致的在大端面处形成的凹刻痕状滚子毛坯缺陷。
3
FLASH : Green roller defect, caused by excessive stock forced out between taper die and head die.