knuckle-joint knurler

例句：

1. 1. He had to work on his knuckle-joint for hours before he could move again.
   他不得不花几个小时来工作他的关节才能再次移动。
2. 2.The doctor advised him to exercise regularly to prevent any knuckle-joint problems.
   医生建议他定期锻炼以防止任何关节问题。
3. 3. She used a knuckle-joint file to smooth the rough surface of the wood.
   她使用一个关节锉来平滑木材的粗糙表面。