weak in the knees
双腿无力的；因为紧张或兴奋而感到腿软的
口语·表达震惊或紧张
英文释义
to feel a sudden loss of strength or confidence, often due to strong emotions or attraction
例句
The news of the accident made her weak in the knees.
典故来源
与“weak at the knees”同源，强调因情绪冲击而失去支撑力。