Akademik

Н-113

ВАЛИТЬСЯ/СВАЛИТЬСЯ (ПАДАТЬ) С НОГ (от чего) coll VP subj: human or, rare, animal more often impfv ) to be unable to stand on one's legs as a result of extreme fatigue, illness etc: X валился с ног = X was ready to drop (to collapse) X was dead on his feet X could hardly stand (stay) on his feet X was dropping (collapsing) (from exhaustion etc) X was dropping in his tracks X was dead tired (dog-tired)).

(Зилов:) Нельзя так много работать. Мы не лошади. Я падаю с ног (Вампилов 5). (Z.:) It's no good working as hard as that. We're not cart-horses. I'm dead on my feet (5a).

«...Почти все спят...» - «Они с ног валятся после вчерашней пьянки, их теперь не добудишься» (Шолохов 5). "...They're nearly all asleep." They could hardly stay on their feet after yesterday's boozing, you won't wake them now" (5a).

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.