[1] Harvard Med Sch, Dept Phys Med & Rehabil, Boston, MA 02115 USA
[2] Spaulding Rehabil Hosp, Charlestown, MA USA
[3] Massachusetts Gen Hosp, Boston, MA 02114 USA
[4] Brigham & Womens Hosp, 75 Francis St, Boston, MA 02115 USA
[5] Univ Nebraska Med Ctr, Coll Allied Hlth Profess, Omaha, NE USA
[6] Univ Cent Caribe, Bayamon, PR USA
[7] Univ Puerto Rico, Dept Phys Med Rehabil & Sports Med, Sch Med, GPO Box 365067, San Juan, PR 00936 USA
[8] Univ Puerto Rico, Dept Physiol, Sch Med, San Juan, PR 00936 USA