1. School of Physiotherapy, University of Otago, Christchurch, New Zealand
2. Department of Medicine, Christchurch School of Medicine, University of Otago, Christchurch, New Zealand
3. Christchurch Movement Disorders and Brain Research Group, Christchurch, New Zealand
4. Department of Neurology, Christchurch Hospital, Christchurch, New Zealand
5. Department of Medical Physics and Bioengineering, Christchurch Hospital, Christchurch, New Zealand
6. Department of Speech and Language Therapy, University of Canterbury, Christchurch, New Zealand