Larkin was born with the birth defect spina bifida.[4] He stated that his "will to campaign" came from "the frustrations I experience relating to having a disability".[5]
He ran for Letterkenny Town Council as a Fine Gael candidate in the 2009 elections, but was unsuccessful.[4]
He attended a hearing on disability issues at the European Parliament in 2012.[6] Larkin was elected chairperson of his country's national campaign for disabilities in 2013.[4][7]
He was one of twenty participants from fourteen different countries chosen to attend a conference in Budapest in March 2014.[8][9]
In 2015, Larkin became involved in a dispute with Facebook over posts it decided were not offensive, among which was an advertisement for a spina bifida doll that encouraged the buyer to abuse it.[10] He thought about deleting his account but instead he led a petition against the posts, which was ultimately successful.[11][12]
In 2016, Larkin became involved in a dispute with the makers of Coronation Street over the language used by character David Platt to his grandmother Audrey Roberts in an episode of the TV series.[3] Also that year, he worked on an accessibility guide for his local area.[3][13]
Among the issues he spoke out against were being sent two tickets for each football game he attended, one of which he had to pay for and intended for a companion which he did not need;[14] illegal parking in disabled spaces;[13][15][16][17] measures imposed by government on disabled people;[18] discrimination by taxi drivers;[2] and securing parking spaces outside court for disabled people.[19]
Larkin died suddenly in hospital in 2020 at the age of 48.[4] He had been active in calling for disability access to polling stations in the weeks before his death.[20] Days before he died, he had been admiring the weather.[21] He was survived by his wife Pauline, his mother Brighdin, his father Frank Snr and his siblings: Louise, Geraldine, Olga, Sharon, Linda, Paul and Gareth.[22][23][24][25]