Styrofoam may have the reputation for being lightweight, but an eastern Newfoundland woman has learned that it can still pack a mighty punch.

A bundle of Styrofoam blew off a truck on the Conception Bay Highway on Saturday morning, and struck a woman who was walking along the road, RCMP Sgt. Mike Oullette said.

The woman, 67, was knocked to the ground. She was then taken to hospital, where she is still receiving treatment, Oullette said Tuesday.

"I was talking to her spouse yesterday and apparently her injury, because it was a head injury, caused brain swelling, so they had to do an MRI," he said.

"Hopefully she'll be released soon and none the worse for wear for the flying Styrofoam."

Oullette said the RCMP is investigating how the Styrofoam was able to fall off the truck.

He said charges may be laid.