Scrubbing floors on one's hands and knees is a common image used to highlight the drudgery and poor social status of women in the past.
Was cleaning floors in this way actually common in the past or is this hyperbole?
Historically many maids suffered from Prepatellar bursitis, an inflammation of the Prepatellar bursa caused by long periods spent on the knees for purposes of scrubbing and fire-lighting, leading to the condition attracting the colloquial name of "Housemaid's Knee".
It was a common condition caused by the hard physical labor required to maintain a home in that era. If you have an opportunity, watch the BBC reality TV show 1900 House and that will give you some idea of the struggles faced by women working in a home during that time.