This is the progression of world record improvements of the 400 metres M55 division of Masters athletics.
Key
HandAutoAthleteNationalityBirthdateAgeLocationDateRef51.18Timothy Munnings22 June 1966Nassau15 February 202551.92Allen Woodard16 January 1969Houston20 April 202452.24Charles Allie20 August 1947Carolina12 July 200352.52Ralph Romain20 July 1932Alexandria22 July 199053.81Berthold Neumann19 December 1930Radolfzell6 September 198654.56Rudolph Valentine12 July 1923Eagle Rock9 June 197955.9 Charles Beaudry4 September 191818 August 1974
References
Masters Athletics 400 m list