求翻译：为了增加乘客坐姿的横向稳定性，座面和靠背在横向方向上都带有一定的弧度，弧度半径不能过大，起不到稳定的作用。是什么意思？

In order to increase the lateral stability of passengers sitting, on both the seat and back in the horizontal direction with a given in radians, radians cannot be too large a RADIUS, up to the stabilizing effect.