Reconnecting the Brain with the Rest of the Body: Brain and Biomechanical Mechanisms Associated with Persistent Low Back Pain

Motor control adaptions on spinal and supraspinal levels are thought to contribute to persistent pain. However, their underlying biomechanical, psychological, and cortical mechanisms, in particular their potential pain-provoking interactions, are unclear and need to be disentangled. For example, there is a common belief that lifting with a round-back posture is dangerous for the back. Possibly driven by such fear avoidance beliefs, some individuals experiencing low back pain (LBP) adopt a protective trunk movement strategy by keeping a lordotic posture in everyday movements such as lifting. Long-term maintenance of a protective movement strategy is thought to trigger pain-provoking mechanisms, such as increased paraspinal tissue strain, muscle fatigue, and cortical reorganization through reduced proprioceptive input. To discuss these mechanisms and their potential association with LBP, the presentation will 1) highlight the role of psychomotor interactions in LBP and asymptomatic subjects by presenting the relationship between pain-related fear, spinal kinematics, and muscle activity, and 2) include new experimental data on the cortical representation of paraspinal sensory input along the thoracolumbar axis, its possible alteration in LBP patients, and its relationship to motor control adaptations. Possible clinical implications are discussed.