A prop forward, he represented Wales at youth level and played club rugby for Pontypool RFC.

[3] Addison began his career with Pontypool RFC as a prop and represented Wales at youth level in a 9–6 victory against France in March 1964.

As a result of the injury, Addison swallowed a piece of chewing gum that became stuck in his throat.

[4] Doctors initially feared that he would only survive for three weeks but he lived in hospital for the following 44 years of his life during which representatives of Pontypool RFC visited him regularly.

[3][4] He spent several years at Stoke Mandeville before he was moved to Rookwood Hospital in Cardiff in order to be closer to his family.