The word(s) "knee" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) So, by thy Lord, without doubt, We shall gather them together, and (also) the Evil Ones (with them); then shall We bring them forth on their knees round about Hell;

(سورة مريم, Maryam, Chapter #19, Verse #68)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) But We shall save those who guarded against evil, and We shall leave the wrong-doers therein, (humbled) to their knees.

(سورة مريم, Maryam, Chapter #19, Verse #72)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(3) And thou wilt see every sect bowing the knee: Every sect will be called to its Record: "This Day shall ye be recompensed for all that ye did!

(سورة الجاثية, Al-Jaathiya, Chapter #45, Verse #28)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)