flexor carpi ulnaris

例句：

1. 1. This muscle helps the hand and wrist to bend forward when you are playing tennis.
   这个肌肉在打网球时帮助手和手腕向前弯曲。
2. 2. The flexor carpi ulnaris is responsible for controlling the movement of the thumb and index finger.
   桡侧腕屈肌负责控制拇指和食指的运动。
3. 3. Injuries to this muscle can cause pain and difficulty in using the hand.
   这个肌肉受伤会导致疼痛和手部使用困难。