Musculus semispinalis

例句：

1. 1.The muscles in the back are responsible for supporting the spine.
   背部的肌肉负责支撑脊柱。
2. 2.Muscles are essential for maintaining good posture.
   肌肉对于保持良好的姿势至关重要。
3. 3. During exercise, it's important to engage all the muscles in your body.
   锻炼时，重要的是要激活你身体中的所有肌肉。