Iconic Liverpool manager Bob Paisley wrote in his autobiography that Kennedy was "one of Liverpool's greatest players and probably the most underrated."
He left Anfield in 1982 and spells at Swansea and Hartlepool followed, but his body was already in the grip of the crippling disease which was affecting his mobility.
Kennedy was diagnosed with Parkinson's Disease in 1984 and lived with the condition for decades in a testament to the strength of his character.
A testimonial game between Liverpool and Arsenal was held in his honour in 1991.
Later that year he sold his medals and 17 England caps to help raise funds for his care.