Our Team

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Roger Gonzalez, PhD, PE

Dr. Roger Gonzalez is Chair and Professor of Engineering Education and Leadership at The University of Texas at El Paso (UTEP) and holds graduate degrees in Biomedical and Mechanical Engineering. He earned his PhD and MS in Engineering from the University of Texas at Austin and his BS in Mechanical Engineering from the University of Texas at El Paso.

He was awarded a prestigious National Institutes of Health (NIH) National Research Service Award (NRSA) for his postdoctoral work in neuromuscular control and musculoskeletal biomechanics on children with juvenile rheumatoid arthritis, while working as a research scientist at Northwestern University Medical School and the premier Rehabilitation Institute of Chicago. His scholarly efforts with students have focused on musculoskeletal modeling, dynamic modeling of human movement and neuromuscular control with applications to upper extremity neuroprosthesis and on the effects of knee ACL-deficiency on osteoarthritis.

Dr. Gonzalez is an Elected Member of the College of Fellows of the American Institute for Medical and Biological Engineering (AIMBE). More than 125 publications detail his research endeavors having received multiple National Science Foundation (NSF), National Institutes of Health (NIH) and Department of Education research grants, including support from various foundations for his international humanitarian endeavors. He has also received the American Society of Engineering Educators (ASEE) Teaching Award, the Minnie Stevens Piper Foundation Award for 2008, and LeTourneau University’s top research and scholarship award. He also serves as an engineering program evaluator for ABET (Accrediting Board for Engineering and Technology), which is the sole U.S. entity for accrediting engineering programs throughout the United States.

As Founder, CEO and President of LIMBS International, Dr. Gonzalez has worked with students in Africa, Asia, Europe, Australia and Latin America on various international engineering research and humanitarian projects.

Trevor Bergman

Trevor Bergman is Director of Learning for LIMBS for LIMBS International. He has Bachelor degrees in Human Kinetics and Education, as well as a Master’s of Education (Leadership and Administration) from Deakin University, Australia.

Prior to his appointment at LIMBS, Trevor served as Athletic Director, PE and Health Department Chair and coach at four different schools over a 10 year period, eight of which were spent overseas in South Korea, Myanmar and China.

As Director of Learning for LIMBS, Trevor educational partnerships of the organization, working closely with schools and other organizations to further the mission of LIMBS International.

Aaron Nystrom

Aaron Nystrom is the Director of Engineering Operations for LIMBS International. He spent his childhood in the Peruvian Amazon jungle and through that experience developed a longing to be a blessing to people in the developing world.

Aaron has a Bachelor’s degree in Mechanical Engineering from LeTourneau University. Following his graduation from LeTourneau, Aaron worked as an engineer in Southern California for 10 years designing seismic restraints for HVAC systems. During that time he also earned a Master’s degree in Bible Exposition from Talbot School of Theology. His role at LIMBS is to direct and coordinate all engineering activities, including student research, new product development and the manufacturing of current prosthetic components.


Oscar Montoya Gonzalez

Oscar Gonzalez Montoya is the Director of the Community-Based Rehabilitation (CBR) program. From a very young age, Oscar wanted to help the poor in his native Mexico. After earning his degree in aircraft maintenance and mechanics, Oscar joined MAF as a manager and had the opportunity to oversee a fleet of aircraft that served poorest of the poor in Oaxaca, Mexico.

Oscar then moved into leadership with Family life as a national director with the focus of strengthening families throughout Mexico. These life and work experiences have made Oscar a perfect fit with LIMBS as the Director of CBR. Oscar also oversees all of LIMBS’ partnerships and activates throughout Latin America. 

Cristal O'Kuma-Barrera

Born and raised in El Paso, Cristal has lived in four countries and received her Bachelor’s degree at UTEP. Before joining the LIMB’s team in July 2014, she taught in public schools for two years.

Now, she helps coordinate the Learning for LIMBS program that engages students across the nation through lessons that combine STEM education with global awareness and service learning. Cristal is also responsible for coordinating LIMBS’s annual signature event, Night in West Texas.

Margaret Davis

Margaret Davis serves as an Educational Consultant for the Learning for LIMBS program. She holds a Bachelor of Arts and Master of Science from Baylor University. She has completed post-graduate institutes at the Harvard Graduate School of Education. She has presented at international, national and state conferences. In addition to many years of teaching, Margaret has held administrative positions in the Highland Park Independent School District, Longview Independent School District and Garland Independent Schools District. She is active in Texas IB Schools where she serves on the Board and as the Director of International Baccalaureate for the Alcuin School in Dallas, Texas. She works with the development of high-quality lessons aligned with state and national standards, which provide students the opportunity for service learning as they connect their academic content to the work of LIMBS and take action to touch the lives of amputees around the world.

John Burger

John Burger is an American Board Certified CPO. He did his post graduate studies in prosthetics and orthotics at New York University Medical Center. He received his Master’s Degree in O&P from the University of Connecticut in 2002.

He lived and worked as a CPO in Turkey for 10 years. He most recently worked at New England Orthotic and Prosthetic Systems as a manager and practitioner for the past 10 years. During that time he volunteered with Physicians for Peace to help establish a prosthetics center and O&P school at Dicle University in Diyarbakir, Turkey. He also volunteered with LIMBs International and went to Nairobi, Kenya to help train prosthetists who want to use LIMBs Relief 4 bar knee for above knee amputees.

He most recently started full time working with LIMBS International to use the prosthetics center in Diyarbakir, Turkey for many Syrian and Iraqi refugees who experienced limb loss due to the war. A number of Community Based Rehabilitation (CBR) centers are also being planned to help the amputees learn how to use their prosthetic devices properly.