The intention was to to 'explore' the capabilities of 'adults with intellectual disabilities' for sports and physical activities, according to the Special Olympics' website.

In 1968, just weeks after the assassination of another brother, Robert, who was running for the Democratic presidential nomination, Shriver launched the first International Special Olympics Summer Games.

They attracted 1,000 individuals with intellectual disabilities from 26 US states and Canada to compete in track and field and swimming.

By 2008, the Special Olympics celebrated its 40th anniversary, drawing nearly 3 million athletes from more than 180 countries to the event that followed the regular Olympic Games in Beijing.

'The Special Olympics movement is saddened to hear that our founder, Eunice Kennedy Shriver, is hospitalized. Our thoughts and prayers are with Mrs Shriver and her family at this time,' organisation President Brady Lum said in a statement last week.

Shriver's idea was to use 'sports as the catalyst for respect, acceptance and inclusion,' Lum noted.