Jefferson City police said Monday officer Shawn Dumsday was improving and had been stabilized.
The Jefferson City Fraternal Order of Police (FOP)/Police Officers Association has started a fund to assist with Dumsday's injuries.
Dumsday is a more than 15-year veteran of the department and is currently a member of the Traffic Unit.
According to the department, Dumsday was on a motorcycle responding to a disturbance with a weapon downtown when he lost control of it Thursday.
Investigators say Dumsday was traveling northbound near the 1300 block of Jefferson Street when he lost control of the motorcycle. The motorcycle left the side of the roadway and he was ejected.
A second officer at the scene and nearby drivers started administering first aid to Dumsday before emergency crews arrived.
He was transported to St. Mary's Health Center in Jefferson City with serious injuries, then taken to University Hospital.