Individuals with nonspecific low back pain (NSLBP) show a decreased sit-to-stand-to-sit (STSTS) performance. This dynamic sensorimotor task requires integration of sensory and motor information in the brain. Therefore, a better understanding of the underlying central mechanisms of impaired sensorimotor performance and the presence of NSLBP is needed. The aims of this study were to characterize differences in sensorimotor functional connectivity in individuals with NSLBP and to investigate whether the patterns of sensorimotor functional connectivity underlie the impaired STSTS performance. Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. Based on the center of pressure displacement, the total duration of the STSTS task was determined. In addition, resting-state functional connectivity images were acquired and analyzed on a multivariate level using both functional connectivity density mapping and independent component analysis. Individuals with NSLBP needed significantly more time to perform the STSTS task compared to healthy controls. In addition, decreased resting-state functional connectivity of brain areas related to the integration of sensory and/or motor information was shown in the individuals with NSLBP. Moreover, the decreased functional connectivity at rest of the left precentral gyrus and lobule IV and V of the left cerebellum was associated with a longer duration of the STSTS task in both individuals with NSLBP and healthy controls. In summary, individuals with NSLBP showed a reorganization of the sensorimotor network at rest, and the functional connectivity of specific sensorimotor areas was associated with the performance of a dynamic sensorimotor task.
Keywords: brain connectivity; central nervous system; functional connectivity density mapping; independent component analysis; postural control; resting-state functional magnetic resonance imaging; sensorimotor control.