Michael is an injury epidemiologist who has been working for the University of Otago, Wellington since 2006.

His research interests include:

Home injury prevention
Road safety
Active travel

He led the Home Injury Prevention Intervention, a major randomised controlled trial funded by the NZ Health Research Council that looked at the effectiveness of home modifications to prevent fall injuries. He is a principal investigator in two research programmes hosted by the University of Otago, Wellington: He Kāinga Oranga (the Housing and Health Research Programme) and the New Zealand Centre for Sustainable Cities. He was co-winner of the Royal Society Te Apārangi 2021 Rutherford Medal for preeminent research.

Michael is on the editorial boards of three international journals, Accident Analysis and Prevention, the Journal of Transport and Health and the Journal of Road Safety.