The elderly woman hit on the head by a bicycle wheel thrown from a block of flats will be operated on today, said her son.
"The doctors told us that if she doesn't go for surgery, she might not be able to move again, or that she will take a very long time to recover," Mr Jusman Abdul Aziz, 35, an executive at a freight forwarding company, told The Straits Times.
Doctors said his mother, Madam Mahani Abdullah, 67, needed surgery to help her regain the use of her limbs, he added.
Yesterday, a sedated Madam Mahani drifted in and out of consciousness in a high-dependency ward at the Singapore General Hospital, said Mr Jusman. He said: "There might be complications in surgery because of her age, but it is, at least, a chance for her to move again."
Madam Mahani was walking below Block 1, Eunos Crescent last Friday at about 3pm when the bicycle wheel landed on her head, Shin Min Daily News reported.
A witness told the Chinese evening paper that she fell to the ground and appeared to be in a lot of pain though it did not look like she was bleeding.
On Saturday, a 16-year-old boy was charged in court with committing a rash act in relation to the incident, the latest in a recent series of "killer litter" cases.
He is believed to be the same teenager who was arrested last December after a brick hurled from his flat at the same block injured a passer-by.
The police have received reports of four "killer litter" cases at the Eunos Crescent address between June 22 and Dec 13 last year. Items thrown included bricks, a dumbbell and water dispenser.
Other cases of deadly litter include one in which a 13-year-old boy was arrested last month for allegedly throwing two bricks from the 12th floor of a Housing Board block in Jalan Bukit Merah in March.
In January, two men, believed to be in their early 20s, were arrested for allegedly throwing a sofa from a fourth-floor flat in Jurong West.