Multiple Sclerosis or MS is a progressive and incurable disease of the central nervous system that impairs movement and other body functions. About 4,000 New Zealanders have it, and Christine O'Sullivan is one of them.
She got her diagnosis a decade ago. Faced with a gradual deterioration in her movement and motor skills, she's rebelling against the traditional approach of sitting in a mobility device like a wheelchair or a mobility scooter to get about. Staying seated just seemed like it made it more difficult to speak to people and to stay active, fit and sociable.
So instead she's using a walking bike called the Alinker, invented by a Dutch designer called Barbara Alink for her own mother.
The Alinker is a pretty unusual looking yellow tricycle. It's got two wheels at the front and a smaller one at the back, the rider leans on a seat and then scoots along as there are no pedals. Plus, this trike folds up and fits in the back seat of a car.
