Boomerang - Brentwood

4530 Balfour Road Ste E, Brentwood, CA 94513

Fax: (925) 691-9807

Clinic Hours: Mon-Fri 8:00am to 4:30pm Sat 8:00am to 2:00pm

Clinic Hours:

1st and 2nd Wednesday of each month from 9am to 4pm.

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Current Patients:
Call to schedule: (925) 691-9806
New Patients:

Contact Our Boomerang - Brentwood

Boomerang - Brentwood - Providers


Carl Fieser, MD

Dr. Carl Fieser is a specialist in Interventional Pain and Physical Medicine and Rehabilitation with IPM Medical Group. Dr. Fieser holds board certification by the American Board of Physical Medicine and Rehabilitation as well as the American Board of Pain Medicine. Dr. Fieser received his medical education at the University of Kansas School of Medicine, where he also completed his internship and residency in Physical Medicine and Rehabilitation. He then completed a one year fellowship in Musculoskeletal Medicine and Interventional and Chronic Pain Management. As a Physical Medicine and Rehabilitation specialist, he focuses on using the latest non-surgical interventional techniques as part of a multidisciplinary approach to pain management. He strives to provide high quality compassionate patient care with an emphasis on improving function and quality of life. Dr Fieser has a special interest in Sports Medicine and is preparing for a board certification in that field. He is able to perform Electrodiagnostic Studies and is a Qualified Medical Evaluator (QME) for the California Workers’ Compensation System. He is also a healthcare entrepreneur with an interest in health related tech start-ups. Dr. Fieser was raised in Kansas and is an obsessive Kansas Jayhawk Basketball fan, as well as an Oakland A's fan. He also enjoys traveling and shooting medium format photography. Dr. Fieser is available to see patients in our Walnut Creek, Brentwood, and Oakland offices and is fluent in Spanish.


Douglas Grant, MD

Dr. Douglas Grant is a specialist in Physical Medicine and Rehabilitation with IPM Medical Group, Inc., a multi-specialty medical group. IPM Medical Group, Inc. is dedicated to helping injured workers and individuals suffering from chronic pain attain the highest level of functioning possible through an integrated medical, vocational and behavioral management approach. Dr. Grant is a 1998 graduate of University of Texas – Southwestern Medical School and completed residency 2002 at the University of Washington in the Department of Rehabilitation. He is Board Certified in Physical Medicine and Rehabilitation with sub-specialty Board Certification in Pain Management. He has specialized in Physiatry and Pain Medicine. Dr. Grant completed a fellowship in Musculoskeletal Medicine and Pain Management with Integrated Physical Medicine. His greatest interest lies in musculoskeletal and pain issues, as he is most concerned with regaining function and reducing pain. Dr Grant has devoted over 10 years to developing expertise in Physiatry and Pain Management. He has thorough training in spine and peripheral joint musculoskeletal medicine, electrodiagnostic studies, and spinal and peripheral joint injection procedures. He is highly skilled at a variety of advanced non-surgical procedures. He has a unique practice style, blending his high-tech expertise in sports, spine, occupational & pain medicine with a special compassion for the human condition. His father was in the US military, and, together, lived at many military bases around the world. He migrated from his adopted home state of Texas to Washington for residency training at the University of Washington, and eventually migrated to northern California. He loves living here with his wife and two children. Dr. Grant feels privileged for the opportunity to participate in the health care of the East Bay community.


Jacob Rosenberg, MD

Dr. Jacob Rosenberg has been treating pain for over 35 years and graduated from Vanderbilt University, the University of Maryland Medical School and then completed an anesthesia residency at the University of Texas Houston. He first began treating chronic pain when he was an assistant professor of anesthesiology at the University of New Mexico School of Medicine in 1984. After five years in private practice in Davis, California, he completed a pain management fellowship at the University of Utah School of Medicine, staying on as an assistant professor of anesthesia in pain management.  In 1995 he founded IPM (now Boomerang Healthcare), initiated a pain management fellowship program, and in 2002 started a multi-disciplinary functional restoration program along with Dr. Howard Rome. Dr Rosenberg’s philosophy for the treatment of chronic pain involves a partnership between the patient and physician. He understands that patients need information in order to make decisions and to take an active role in their care. His approach is to first identify any correctable pathology, then recommend options for managing pain and beginning rehabilitation. Dr. Rosenberg’s approach does not focus solely on interventions that provide temporary pain relief. His goal is to educate patients so that they can actively participate in treatment more effectively improving their function and quality of life. Dr Rosenberg is available for consultations and treatment of injured workers.


Kenneth Kim, MD

Dr. Kenneth Kim completed his undergraduate education at the Johns Hopkins University in Baltimore, MD. He completed his medical school training at Medical College of Pennsylvania/Hahnemann University School of Medicine in Philadelphia, PA. Dr. Kim later completed a residency training program in Physical Medicine and Rehabilitation at Temple University Hospital in Philadelphia, PA. Fellowship training in Pain Management then followed at Integrated Pain Management in Concord, CA. Dr. Kim is double board certified in Physical Medicine and Rehabilitation and Pain Management. Dr. Kenneth Kim, was raised in southern California and now lives in the East Bay area with his wife and two young children.


Matthew Johnson, DO

Dr. Matthew Johnson is a ABPMR Board Certified Physiatrist and Interventional Pain Management Specialist. He is originally from Missouri and graduated from the University of Missouri- Columbia with honors in Biology. Dr. Johnson completed his medical training at Western University in Southern California followed by a one year internship at Pacific Hospital of Long Beach. He completed a residency in Physical Medicine and Rehabilitation at the University of California-Irvine where he served as the Chief Resident during his final year. Following residency he completed a one year fellowship in interventional pain management. Dr. Johnson’s interests include neuropathic pain, back and neck pain, joint pain, headaches, fibromyalgia pain, abdominal pain, non-surgical management and rehabilitation of orthopedic issues and industrial injuries, and general debility. He also performs Electrodiagnostic Studies (nerve conduction studies and electromyography) to diagnose nerve problems. He is an expert in interventional pain techniques such as radiofrequency ablation, epidural steroid injections, selective nerve blocks, Botox administration, neuromodulation, and joint injections. Dr. Johnson is a Qualified Medical Examiner for the State of California Worker's Compensation system and is an expert in matters of disability and function. Dr. Johnson is available to see new patients immediately.


Morad Nasseri, MD

I completed my medical school in 2011 at Oregon Health and Science University and moved to Detroit, Michigan, pursuing my training in Neurological Surgery. Life events changed my path and I completed my residency training in Neurology. During my residency, participating in an elective rotation in interventional pain management was instrumental in helping me find the path I chose to become a pain specialist physician. Ideally, I like to pursue treatment of pain from in a multidisciplinary fashion and I believe my training in Neurology and deep understanding of the nervous system will be an asset to me in this path. I am excited to join IPM to pursue my career as a pain medicine neurologist, and I will continue to participate in research to find even better ways to help our patients to have a better quality of life, despite the injuries and ailments causing them pain.


Navjeet Boparai, MD

Dr. Navjeet Boparai is a specialist in Interventional Pain and Physical Medicine and Rehabilitation. Dr. Boparai holds board certification by the American Board of Pain Medicine and the American Board of Physical Medicine and Rehabilitation. Her practice is focused in the area of Pain Medicine. Dr. Boparai specializes in multiple aspects of pain management, including spinal injections, chronic and acute musculoskeletal pain, neuropathic pain, and electro diagnostic studies. Dr. Boparai strives to provide comprehensive medical treatment enabling her patients to lead a more functional and fulfilling life. Dr. Boparai graduated from the University of California, Los Angeles in 2000. She obtained her undergraduate degree in Neuroscience. She then completed a post-graduate program at Rosalind Franklin University of Health Sciences in North Chicago, Illinois, where she obtained a Master of Science in Applied Physiology. She went on to receive her medical degree in 2005 from Chicago Medical School. She then completed a one year transitional internship at Alameda County Medical Center in Oakland, California. She completed her residency in Physical Medicine and Rehabilitation at Stanford University Hospital and Clinics. Dr. Boparai completed a one year fellowship in Interventional and Chronic Pain Management with IPM Medical Group, Inc. Dr. Boparai was born and raised in California and currently lives in the East Bay with her husband and three children. She is available to see patients in our Walnut Creek and Brentwood offices. She is fluent in Spanish, Hindi, and Punjabi.


Eric Beane, PA

Eric Beane is a California licensed Physician Assistant (PA) at the Brentwood, Walnut Creek and Oakland locations. He graduated from Samuel Merritt University with his Master of Physician Assistant and is certified by the National Commission on Certification of PAs. Eric has also completed extensive graduate work in Kinesiology with an emphasis in rehabilitation at California State University, East Bay while concurrently working as a Physical Therapist Aide. Previously, he conducted various philanthropic and volunteer work, including traveling to Ecuador, to provide compassionate care to the underserved population. Eric was born and raised in the San Francisco Bay Area and currently lives in the East Bay. 

In his free time, Eric is pursuing his private pilot’s license, is an avid free diver and swimmer, including participating in annual swims from Alcatraz Island to the San Francisco Marina District’s Aquatic Park. 


Melissa Strickland, NP

Melissa Strickland is a Nurse Practitioner at the Brentwood and Walnut Creek locations. She graduated from Mendocino College Nursing Program in 2009 with her Associate of Science in Nursing, and later earned her Bachelor of Science in Nursing at the University of Phoenix in 2012. She went on to obtain her Master of Science in Nursing as a Family Nurse Practitioner at the University of Phoenix in 2015 and is Nationally Board Certified with the American Association of Nurse Practitioners. Melissa has worked as a Registered Nurse in a variety of areas including critical care transport, hospice/palliative care, emergency room, orthopedic post-operative, cardiothoracic, and neurologic care. Previously, she worked at the John Muir Medical Center in Concord as a Registered Nurse and has transitioned into the specialty of pain management providing direct individualized care as a Nurse Practitioner. Melissa was born and raised in Mendocino County and currently lives in the East Bay with her husband and two children.


Sang Yoon, L.Ac

Sang Won Yoon has been a Diplomat of Oriental Medicine since 2004 (NCCAOM) and California licensed acupuncturist since 2005. He graduated with a Master in Traditional Chinese Medicine from the Academy of Chinese Culture and Health Science in Oakland, CA. After passing his California board exam, he went to Shanghai, China for a post-graduate internship at Shu Guang TCM Hospital. Afterward, he went to Kyung Hee University Hospital, in Seoul, South Korea, where studied in the Oriental medicine wing of the hospital at the internal medicine, neuropsychiatry, rehabilitation medicine, and gynecology departments. Sang Won has traveled all around the world treating and educating people about acupuncture. I have a passion for Chinese Medicine and trying to help improve the lives of my patients.


Scott Gwilliam- NP

Scott graduated from Samuel Merritt University with a Bachelor of Science in Nursing in 2015 and later returned to Samuel Merritt to earn a Master of Science in Nursing as a Family Nurse Practitioner in 2019.  He is Nationally Board Certified through the American Nurses Credentialing Center as a Family Nurse Practitioner.  As an RN for six years, Scott has worked in both Skilled Nursing and Acute Care working in areas specializing in trauma, neurology, orthopedic and post-surgery.  Before joining IPM he was working as a Nurse Practitioner at vaccine sites across the Bay Area and Central Valley helping people become vaccinated against Covid 19.  Growing up, Scott had a love for athletics and through personal experience dealing with injury, combined with his training, he has developed a passion for pain management, orthopedics and helping people recover as much as possible from injury.  Scott was born and raised in the East Bay, where he lives with his wife and children.


Shirley Carrillo, NP

 Shirley Carrillo is a Nurse Practitioner at both the Brentwood and Walnut Creek IPM locations.  Shirley Graduated as a Family Nurse Practitioner from UOP with a Post Masters’ Degree with Honors and is still a current member of Sigma theta Tau.  

Her extensive experience as a Nurse and a Nurse Practitioner has led her on a pathway to med surgery, OBGYN and Peds, Cardiology with Telemetry, Chemotherapy Nurse, Post Anesthesia Recovery room, Emergency room Nurse, Case Management, Allergy Nurse, CPR/ACLS instructor, Telephone Advice nurse and Pain Management Specialist. Outside of Work Shirley Walks her dog Zorro daily, she exercises and participates in fitness events.  


Vina Nguyen, NA

Vina Nguyen is an NCCPA-certified Physician Assistant with a Master of Health Services from the University of California at Davis. She received her Bachelor of Science in Biology at Georgia State University. Her focus has been primarily in Pain Management and Physical Medicine & Rehabilitation. She practiced at Pain & Spine Consultants in Tennessee for 3 years before moving back to California. She is skilled in joint injections and trigger point injections. She believes in a holistic and multi-disciplinary approach to pain and also utilizes physical therapy, acupuncture, and meditation practices to help restore function and quality of life for her patients. In her free time, she enjoys hiking, trying new food, traveling, and listening to podcasts and music.