Spatiotemporal dynamics of brain function network during proprioception rehabilitation after anterior cruciate ligament reconstruction: A randomized trial

Purpose In this study, we aimed to examine the dynamic functional network connectivity (dFNC) patterns underlying proprioceptive functional recovery following anterior cruciate ligament reconstruction (ACLR) from a spatiotemporal dynamics perspective. Methods Twenty‐six patients with ACLR were randomly assigned to either an intensive proprioception training trial or routine rehabilitation control group for 4 weeks. Average track error (ATE) and average freeweight variance (AFV) were measured to quantitatively evaluate proprioceptive function before and after intervention. The dFNC analysis focused on temporal variability metrics of brain network states, including fraction time (FT), mean dwell time (MDT) and number of transitions (NT), as well as spatial variability characteristics quantified through functional connectivity (FC) patterns. Analysis examined metrics' link to proprioceptive improvement. Results Four optimal repeated FC states were found for patients with ACLR. Post‐intervention, the trial group exhibited an increase in the NT. State 1 demonstrated significant increases in FT and MDT, with enhanced FC between the sensorimotor (SM) network and cognitive control (CC) network, default mode network, cerebellar (CB) network, as well as between the CB and visual (VI) networks, while FC between the SM and VI networks decreased (all p < 0.05, false discovery rate corrected), reflecting a more densely connected local state. The change in FT in State 1 was positively correlated with improvement in the ATE ( r = 0.621, p = 0.031) and AFV ( r = 0.584, p = 0.046), while changes in MDT ( r = 0.640, p = 0.025) and FC between the SM and CC networks ( r = 0.580, p = 0.048) were positively correlated with improvements in AFV. Conclusions The improvement of proprioceptive function following ACLR is closely associated with the optimization of spatiotemporal dynamics of brain networks, as reflected in the flexibility and stability of motion planning and balance control abilities, as well as improvements in cognitive and visual processing efficiency. Clinical rehabilitation strategies may benefit from incorporating increased visual‐cognitive dual‐task exercises. Level of Evidence Level I.