Eight Weeks Of Attentionally Focused Neuromuscular Training Changes Single Leg Hop Performance And Brain White Matter Architecture

A growing body of evidence suggests that the direction of attentional focus to external cues during training may amplify the effects of traditional neuromuscular training designed to improve performance. The degree to which these effects might be due to changes in brain white-matter pathways remains largely unknown. PURPOSE: To relate changes in white matter architecture to changes in single leg hop performance (SLHP) after an eight-week training intervention and test for differences between externally and internally focused groups. METHODS: Twenty-nine healthy, recreationally active participants (17 females; Age = 21.9 ± 3.2 years) were randomly assigned to one of three training groups: external (n = 10), internal (n = 9) or no focus of attention (n = 10). All participants performed lower extremity body-weight strength and stabilization exercises three times per week for 8 weeks. SLHP was assessed before and after training. Structural (MPRAGE) and diffusion-weighted MRI (64 directions; bval = 1300 s/mm2) were performed before and after training. Individual diffusion MRI data were reconstructed in standard space to calculate spin distribution functions that define a 'local' connectome. Group connectometry was performed to test for changes that were i) associated with changes in SLHP and ii) different between the attentional focus groups. Bootstrap resampling (4000 permutations) estimated the false discovery rate (FDR). RESULTS: SLHP improved on average across all groups [t(28) = 5.1, p < .0001]. Increased SLHP was associated with increased connectivity in the left corticostriatal tract and longitudinal fasciculus (FDR = .030) and decreased connectivity in the right corticostriatal tract and thalamic radiation (FDR = .020). Compared to internally focused training, externally focused training was associated with a large increase in SLHP (Cohen's d = .85), increased connectivity in bilateral corticostriatal tracts and longitudinal fasciculus (FDR = .001), and decreased connectivity in the right thalamic radiation (FDR = .005). CONCLUSION: The benefits of neuromuscular training may be related to neuroplasticity in white matter tracts within brain motor and association pathways. Improvements observed after externally focused training may be associated with more diffuse effects in similar circuits.