Functional Connectivity Alterations After Visual Perturbation Neuromuscular Training In Healthy Active Females

Visual perturbation training via stroboscopic glasses (SG) can improve visual cognitive deficits associated with biomechanical risk factors of lower extremity injury. However, no study has examined the neurologic pathway responsible for visual perturbation training induced neuromuscular adaptations to further support combined visuocognitive and neuromuscular interventions. PURPOSE: To determine the effect of visual perturbation neuromuscular training (VPNT) on brain functional connectivity during a knee motor task. METHODS: Seven female athletes (20.4 ± 1.1 yrs) with 6+ errors on the landing error scoring system (LESS) were enrolled. VPNT consisted of 4 sessions of agility, balance, and plyometric exercises while wearing SG and interacting with external visual stimuli. Functional magnetic resonance imaging (fMRI) measured blood oxygen-level dependent signal (an indirect measure of neural activity) during a dominant right knee motor task (extension/flexion) using a block design. fMRI and LESS data were collected pre/post VPNT. fMRI data underwent standardized preprocessing and a group-level mixed effects analysis to identify differences in neural activity pre and post VPNT during the knee motor task (z > 3.1, p < .05). The left supramarginal gyrus (SMG) and right superior frontal gyrus were the only regions identified to change activity from the intervention and selected as seed regions. Functional connectivity analyses assessed how brain regions coordinated activity with these two seed regions. Separate group-level mixed effects analyses were conducted for each seed region to identify changes in functional connectivity after VPNT (z > 3.1, p < .05). A paired t-test was conducted for LESS errors pre/post VPNT. RESULTS: After VPNT there was a significant decrease in LESS errors (-1.5 ± 1.6, p < 0.040, d = -.78). The left SMG had decreased connectivity with left frontal pole (z = 4.4, p = <.001) and decreased connectivity with left post central gyrus (z = 4.5, p = .019) after VPNT. CONCLUSIONS: Female athletes demonstrated decreased landing errors and decreased functional connectivity between the SMG and cognitive and sensory integration centers after VPNT. These results indicate VPNT may improve neuromuscular capacity and reduce cognitive and sensory reliance for knee motor control. This work was supported by the Department of Defense Peer Reviewed Orthopaedic Research Program. Research Award (81XWH-18-1-0707).