1. MossRehab Gait and Motion Analysis Laboratory, Elkins Park, PA, USA
2. Department of Neurology, University of Freiburg, Freiburg, Germany, and Parkinson-Hospital Ortenau, Wolfach, Germany
3. Novus Therapeutics, Inc., Irvine, CA, USA
4. Department of Neurology, McGill University, Montreal, QC, Canada
5. Allergan, an AbbVie Company, Irvine, CA, USA