求翻译：座椅靠背后倾斜使腰背部得到依靠，加之靠背椅垫的适度柔软性，致使摩擦力较大，可缓冲横向振动对人体的冲击。但要考虑椅垫材质的生理舒适性是什么意思？

Tilt back behind the seat to be relied on, combined with backrest upholstery moderate softness, causing friction is large, lateral vibration of a buffer on the impact of the human body. But taking into account the physiological comfort upholstery material