Introduction

Low back pain (LBP) is associated with $200 billion in lost wages and productivity annually and accounts for over 3.7 million physician visits per year in the United States alone. One common symptom for individuals with cLBP is exacerbated movement-evoked pain during flexion of the lumbar spine, which can lead to significant limitations in function. Recent studies have proposed that assessing movement-evoked pain in individuals with persistent musculoskeletal pain might capture distinct dimensions of pain. Although emerging behavioral paradigms have been proposed to assess movement-evoked back pain, the cortical processes underlying movement-evoked pain in individuals with cLBP are not well understood. Characterizing changes in brain function that are associated with movement-evoked pain, and evaluating how generalizable these changes are, will advance our understanding of the neurophysiological signature of cLBP. The primary goal of this study is to determine the neural oscillations that underlie movement-evoked pain in individuals with cLBP. We will also evaluate neural oscillations during an experimental pain task and during an innocuous grip-force task.

The current study is motivated by questions on the modulation of neuronal oscillations during movement-evoked pain, during experimental pain, and during an innocuous grip force task. We test the hypothesis that movement-evoked pain will be associated with attenuated, rather than enhanced, neural oscillations in sensorimotor cortex in cLBP. We further hypothesize that although the cLBP and the control groups will show similar behavioral results in acute pain perception and grip force production, a general pattern of reduced cortical modulation in the sensorimotor brain regions will be found, suggesting a generalized effect of cLBP on sensorimotor circuits.