Sir Bobby passed away at the age of 86 at Macclesfield General Hospital on 21 October, prompting tributes from around the football world.
During an inquest into his death held at Cheshire Coroner's Court on Wednesday, it was heard that he had been living at The Willows nursing home in Knutsford, which specialises in caring for patients with dementia - as reported by BBC Sport.
Jacqueline Devonish, senior coroner for Cheshire, concluded that Sir Bobby's death was accidental. The hearing was told that he struck a window sill and "possibly a radiator" after losing his balance when standing up from his chair.
Sir Bobby underwent a full body check after his fall, but no visible injuries were noted by staff, who also recorded that his mobility seemed to be unaffected.
Next Match
Paramedics were called to the care home when they later noticed swelling in Sir Bobby's back, and he was taken to a local hospital for assessment before being moved to Macclesfield General.
Sir Bobby, who had been receiving respite care at The Willows since June, died five days after the fall.
Football clubs from across England have held silences in Sir Bobby's memory over the past 10 days, and a funeral service for the 1966 World Cup winner is due to take place at Manchester cathedral on November 13.
Manchester United have also confirmed that over 80,000 fans have signed books of condolence for Sir Bobby, who scored 249 goals across his 17-year playing career at Old Trafford.