 Introduction/Background In the United States, acute low back pain (LBP), with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life years [1]. It is the fifth most common reason for a physician visit in the United States and accounts for approximately 3% of visits to the emergency department [2]. The American College of Physicians and the American Pain Society classify LBP into the following broad categories: nonspecific LBP, back pain potentially associated with radiculopathy or spinal stenosis, and back pain potentially associated with another specific spinal cause [3]. Additionally, guidelines from the American College of Physicians and the American Pain Society [3,4] emphasize a focused history and physical examination, reassurance, initial pain management medications if necessary, and consideration of physical therapies without routine imaging in patients with nonspecific LBP. Duration of symptoms also helps guide treatment algorithms in patients with acute, subacute, or chronic LBP. Additionally, assessment of psychosocial risk factors when obtaining patient history is a strong predictor of patients who are predisposed to developing chronic disabling LBP problems [3]. Although there is great variability in the definition of acute and subacute LBP, for the purposes of this guideline, we will use the Institute for Clinical Systems Improvement definitions of 0 to 4 weeks to define acute LBP, 4 to 12 weeks for subacute LBP, and >12 weeks for chronic LBP [5]. It is clear that uncomplicated acute LBP and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies [4,6,7]. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain.
Low Back Pain PCAs.  Introduction/Background In the United States, acute low back pain (LBP), with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life years [1]. It is the fifth most common reason for a physician visit in the United States and accounts for approximately 3% of visits to the emergency department [2]. The American College of Physicians and the American Pain Society classify LBP into the following broad categories: nonspecific LBP, back pain potentially associated with radiculopathy or spinal stenosis, and back pain potentially associated with another specific spinal cause [3]. Additionally, guidelines from the American College of Physicians and the American Pain Society [3,4] emphasize a focused history and physical examination, reassurance, initial pain management medications if necessary, and consideration of physical therapies without routine imaging in patients with nonspecific LBP. Duration of symptoms also helps guide treatment algorithms in patients with acute, subacute, or chronic LBP. Additionally, assessment of psychosocial risk factors when obtaining patient history is a strong predictor of patients who are predisposed to developing chronic disabling LBP problems [3]. Although there is great variability in the definition of acute and subacute LBP, for the purposes of this guideline, we will use the Institute for Clinical Systems Improvement definitions of 0 to 4 weeks to define acute LBP, 4 to 12 weeks for subacute LBP, and >12 weeks for chronic LBP [5]. It is clear that uncomplicated acute LBP and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies [4,6,7]. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain.