[1] Univ Toronto, Morton & Gloria Shulman Movement Disorders Ctr, Toronto, ON, Canada
[2] Univ Toronto, Edmond J Safra Program Parkinsons Dis, Toronto Western Hosp, UHN,Div Neurol, Toronto, ON, Canada
[3] Krembil Res Inst, Toronto, ON, Canada
[4] Univ Sydney, Discipline Physiotherapy, Fac Hlth Sci, Sydney, NSW, Australia
[5] Tel Aviv Sourasky Med Ctr, Dept Neurol, Ctr Study Movement Cognit & Mobil, Tel Aviv, Israel
[6] Tel Aviv Univ, Sagol Sch Neurosci, Sackler Fac Med, Tel Aviv, Israel
[7] Tel Aviv Univ, Dept Phys Therapy, Sackler Fac Med, Tel Aviv, Israel
[8] Rush Univ, Med Ctr, Rush Alzheimers Dis Ctr, Chicago, IL 60612 USA
[9] Rush Univ, Med Ctr, Dept Orthopaed Surg, Chicago, IL 60612 USA
[10] Newcastle Univ, Inst Neurosci, Newcastle Upon Tyne, Tyne & Wear, England
[11] Auckland Univ Technol, Auckland, New Zealand
[12] Newcastle Upon Tyne Hosp NHS Fdn Trust, Newcastle Upon Tyne, Tyne & Wear, England