back cushion

例句：

1. 1. The office chair has a comfortable back cushion to relieve your back pain.
   这款办公椅有一个舒适的靠背垫，可以缓解你的背痛。
2. 2.She sat on the couch with her back cushioned against the armrest.
   她坐在沙发上，背靠扶手。
3. 3. The new car has an advanced back cushion system that provides excellent comfort.
   这款新车配备了先进的靠背系统，提供极佳的舒适性。