How is christopher reeve heroic in real life?

More than just an actor Christopher Reeves also championed issues on the environment and human rights.  When he was injured in an equestrian competition, he was left paralyzed from the next down.  Drawing strength from his wife and family, Reeve chose to live his life. But it wasn’t just that that made Reeves heroic.  He remembered the other patients who were also undergoing rehab and saw their struggles to be able live life again and realize that there was something he could do despite his injury.  He devoted his time to lobby for better research on spinal cord injuries using his status as a celebrity to work on that goal and through his efforts the Christopher and Dana Reeves Foundation was established.  Thanks to Reeve’s supervision, spinal research has improved and he continued to speak before Congress for more funding on improving the treatment and research of spinal injury.  Until their deaths both Christopher and Dana worked on this and the Foundation has done a lot for helping patients with spinal injury.

Walked would be the participle here. as it is a verb ending in -ed.