back brace meaning in English

背板
反斜撑
后撑

I put the curved back brace on the back , and then , later when the guitar is put together , the curve is lost
我放上有弧度的背板力木，之后吉他组装好时，它的弧度就消失了。
The back brace locks release , allowing the mast backbraces to fold automatically when the mast is lowered from the vertical position
背撑臂可锁定脱扣，当支架从垂直位置上降下来时，允许支架背撑臂自动折叠起来。