15 - Paraspinal muscles

Abstract

As the lumbar spine is relatively unstable compared to the thoracic region, it has been hypothesized that spinal stability relies on the proper functioning of the active (muscle), passive (vertebrae, discs, and ligaments), and neural subsystems (peripheral and central nervous systems). Dysfunction in any of the three subsystems may affect the control of spinal stability and increase the risk of injury if the remaining subsystems cannot compensate successfully. Paraspinal muscles play an important role in maintaining spinal stability and mobility. Research has shown that altered morphology or function of paraspinal muscles is closely related to structural (e.g., scoliosis) or clinical (e.g., low back pain, LBP) problems of the spine. Given technological advancements, clinicians can use various types of medical imaging to examine the morphological changes in paraspinal muscles, which may have the potential to inform clinical decision-making (e.g., selection of treatments or prediction of future clinical outcomes). This chapter provides a brief overview of the (1) anatomy and function of key paraspinal muscles; (2) medical imaging of paraspinal muscles; (3) factors affecting the morphometry of paraspinal muscles; (4) relationship between paraspinal muscle morphometry and spinal degeneration; (5) relationship between paraspinal muscle and LBP or LBP-related disability; (6) effects of exercises on paraspinal muscle morphometry; and (7) clinical implications and future research directions.