Back pain is the leading cause of disability and healthcare expenditures worldwide. Besides cancer, it is also the leading reason for opioid prescription in the U.S. Since there is no universally accepted clinical standard for diagnosing chronic low back pain, clinicians are often unable to identify the root cause.




​In an effort to reverse the nation’s opioid crisis, the National Institutes of Health (NIH) awarded $945 million to institutions across 41 states for grants, contracts and cooperative agreements to support its Helping to End Addiction Long-term Initiative, known as HEAL. As part of HEAL, the NIH formed the BACPAC Research Program, a translational, patient-centered effort to address the need for effective, non-addictive, and personalized therapies for chronic low back pain.  UCSF was awarded three of the program’s 13 grants, which also include two BACPAC technology sites: 1) “Novel imaging of endplate biomarkers in chronic low back pain” led by Aaron Fields, PhD and Roland Krug, PhD, and 2) “Technology Research Site for Advanced, Faster Quantitative Imaging for BACPAC,” led by Sharmila Majumdar, PhD.


In September 2019 the UCSF Dept. of Orthopaedic Surgery received NIH funding for nearly $30 million to establish the Core Center for Patient-centric, Mechanistic Phenotyping in Chronic Low Back Pain, or REACH.

REACH is a Back Pain Consortium (BACPAC) Mechanistic Research Center that conducts translational and clinical research to clarify biopsychosocial mechanisms of cLBP – the interconnection between biology, biomechanics, psychology, and socio-environmental factors – which will be foundational for new diagnostic and therapeutic strategies.

​REACH is led by Dr. Jeffrey Lotz, PhD, the David S. Bradford M.D. Endowed Chair in Orthopaedic Surgery, and Vice Chair of Research within the Department, and Dr. Conor O’Neill, MD, Director of the Department’s Non-Operative Spine Program in the UCSF Spine Center, and includes collaborations with UC DavisUC Irvine, and UC San Diego.

REACH Research Project 

According to the Global Burden of Disease Study 2010, low back pain is one of the most common forms of chronic pain among adults worldwide. As recently as 2015, the National Health Interview Survey indicated that 20 percent of adults in the U.S. reported frequent back pain and 28 percent experienced low back pain that lasted one or more days during the previous three months.

“There is no accepted clinical standard for diagnosing chronic low back pain, and consequently, clinicians are often unable to identify the root cause,” Lotz said. “Back pain is the leading cause of disability and healthcare expenditures worldwide, as well as the leading non-cancer reason for opioid prescription in the U.S.”​

“Our goal over the next five years is to develop an integrated model of low back pain supported by a suite of validated diagnostic tests,” Lotz added. “In doing so, clinicians will be more precise in treating the problem, which should naturally lead to lowering patients’ dependency on opioids to manage their pain.”

Three UCSF REACH research cores align with domains in the biopsychosocial model of chronic low back pain. Infographic courtesy of Conor O’Neill, MD


The REACH program combines an interdisciplinary research team with expertise in basic and clinical sciences:

  • behavior and brain function
  • pathophysiology and advanced imaging
  • clinical trials
  • physical function and biomechanics
  • machine learning and artificial intelligence



The comeBACK clinical study is a 4 year clinical study with follow-up visits every 6 months, in which we aim to enroll 400 participants at four University of California locations (San Francisco, Davis, Irvine, San Diego). Our participants will answer questionnaires, undergo various tests, such as MRIs, Quantitative Sensory Testing and Physical Function testing, and provide biomarker specimens. All of these answers will help identify factors associated with response to chronic low back pain treatment and heterogeneity of treatment effects.