muscles of back

例句：

1. 1. The exercise helped strengthen the muscles of my back.
   锻炼帮助加强了我背部的肌肉。
2. 2.She lifted heavy weights to build her back muscles.
   她举重来建立她的背部肌肉。
3. 3. As a fitness enthusiast, I always focus on building and maintaining my back muscles.
   作为一个健身爱好者，我总是专注于建立和维护我的背部肌肉。