Erwin is past Professor and Chairman of Physical Medicine and Rehabilitation (now emeritus) at Beth Israel Medical Center, the Manhattan campus, Albert Einstein College of Medicine.  He is a former Professor of Clinical Rehabilitation Medicine at ColumbiaUniversity, College of Physicians and Surgeons and former Professor of Rehabilitation Medicine at Mt. Sinai School of Medicine. He served a year of internship at the US Naval Hospital in Subic Bay, before coming to the United States in 1968.  He completed his residency in Physiatry at ColumbiaUniversity’s PresbyterianHospital in 1972 where he served as Chief Resident.  He was certified by the American Board of PM&R in 1974.

   He served as Chief of Rehabilitation Medicine Clinics and Director of the Physiatry Residency Training Program at Columbia from 1975-1989 and moved to Beth Israel, where he retired prematurely in 1997 due to uncontrolled glaucoma. 

   He was elected president of the American Academy of PMR in 1989-90, when the Americans with Disabilities Act was enacted, which garnered him a White House invitation to witness its signing.  He established a think tank for PM&R leaders to discuss matters of importance to the specialty.  He served on the Accreditation Council of Graduate Medical Education (ACGME) Residency Review Committee (RRC) for PM&R from 1988-1994.  During this time, he chaired the drafting of the training requirements for Spinal Cord Injury Medicine.  He also served on the RRC appeals panel.  He was a frequent guest examiner for the American Board of PM&R.  Dr. Gonzalez served on the Board of Directors of the PM&R Education and Research Foundation.  In 1988, he was elected to the Governing Council of the American Hospital Association Section of Rehabilitation.  He was a founding member, and the first elected President of the Physiatric Association for Spine, Sports and Occupational Rehabilitation (PASSOR).

   He was author and coauthor of several peer-reviewed articles and book chapters, on topics related to energy expenditure, medical practice, amputees, electro diagnosis and evoked potentials.  He authored and co-edited books in PM&R, including “The Non-Surgical Management of Acute Low Back Pain” and the 3rd edition of “Physiological Basis of Rehabilitation Medicine” where he served as Editor-in –Chief. 

   Erwin has received many honors, including the AAPMR Zeiter Lectureship.  He was the recipient of the M. Alimurung lectureship during class ‘67 silver jubilee in 1992, as well as the A. Mabini lectureship from the Philippine Academy of Rehabilitation Medicine (PARM).  He also received the PASSOR distinguished Member Award in 2002 and was made Honorary Fellow of PARM in 2006.