- Correspondence to Dr Jennifer Chu, Department of Physical Medicine and Rehabilitation, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
- Received 14 October 2016
- Revised 11 April 2017
- Accepted 31 July 2017
- Published in print 1 July 2017.
- Published online 21 September 2017.
- Published first 4 September 2017.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.