Dr. Jo Armour Smith
Postural control is essential for maintaining balance and facilitating goal-directed action during voluntary limb movement. Altered postural control in the trunk and hip musculature is a characteristic of aging and of multiple neurological and musculoskeletal conditions. It has not previously been possible to noninvasively determine the patterns of altered brain activation underlying impaired postural control in patient populations. The purpose of this study was to demonstrate the feasibility of a novel fMRI-compatible postural control paradigm and identify the brain activation associated with postural control in the trunk and hip musculature during a voluntary lower-limb task. BOLD fMRI imaging was performed on 20 healthy volunteers who performed two versions of a lower-limb task using their non-dominant, left limb. For the supported leg raise task (SLR), the leg is raised from the knee while the thigh remains supported. For the unsupported leg raise task (ULR), the leg is raised from the hip. Significant brain activation during the SLR task occurred predominantly in the right primary and secondary sensorimotor cortical regions. In contrast, significant brain activation during the ULR task occurred bilaterally in the primary and secondary sensorimotor cortical regions, as well as cerebellum and putamen. This novel paradigm enables simultaneous and noninvasive identification of human cortical and subcortical brain activation associated with postural trunk and hip muscle recruitment during a voluntary lower-limb task. Regions activated during the unsupported leg raise, but not during the supported leg raise, were consistent with the planning, execution, and sensory experience of a task involving multisegmental and bilateral postural control, including anticipatory postural adjustments. This paradigm provides a foundation for future studies that will isolate neural mechanisms of impaired postural control in patients with neurological and musculoskeletal dysfunction.
Henslee, Korinne; Smith, Jo Armour; and Glynn, Laura M., "Identifying the Neural Correlates of Postural Control: A Novel fMRI Paradigm" (2022). Student Scholar Symposium Abstracts and Posters. 534.