Contralateral adaptations following unilateral training is commonly associated with the cross-education phenomena. Identifying the contributions to peripheral activation of voluntary muscle contractions can be represented in Beta-band (13-30Hz) oscillations within the human motor cortex. These individualistic electrophysiological changes may display potential hemispheric differences that contribute to skeletal muscle activation patterns following single limb training common in rehabilitation settings. PURPOSE: The purpose of this investigation was to compare the responses of beta-band mean power frequency (MPF) in the motor cortex during varying isometric contraction intensities after blood flow restriction training. METHODS: 13 untrained males (age: 21.7 ± 1.7yrs; height: 176.6 ± 5.2cm; weight: 83.4 ± 12.4kg) were randomly assigned to a BFR (n=8) and non-BFR (n=5) group. Both groups completed 8 isokinetic dorsiflexion training sessions separated by 48 hours at 30% of their session peak torque at a velocity of 60°/s. Pre and post isometric dorsiflexion trapezoidal ramp tracings were recorded at 25%, 50%, 75%, and 100% of their maximal voluntary contraction (MVC). A 64-channel electroencephalography (EEG) cap recorded neural activity during the isometric tracings. Signals were filtered to reject artifact and compute Fast Fourier Transforms. Separate 3-way mixed factorial ANOVAs (group [BFR v non-BFR] x time [pre v post] x location [C5 v C3 v C1 v C2 v C4 v C6]) were used to compare MPF values of the beta-band at all intensities. Additional ANOVAs (group [BFR v non-BFR] x time [pre v post] x leg [right v left] were used to compare the CZ location MPF values of the beta-band at all intensities. RESULTS: There were no significant group x time x location interactions or main effects for MPF at 25%, 50%, or 100% intensities, however there was a main effect for location at 75% (p = .045) (C5 [944.383 ± 150.647], C3 [834.815 ± 150.647], C1 [745.956 ± 150.647], C2 [1057.821 ± 150.647], C4 [1082.626 ± 150.647], C6 [1246.386 ± 150.647]; mean ± SE). When comparing group x time x leg, there was a significant interaction at 25% (p = .049) and main effect on time at 75% (p = .030) (pre [755.646 ± 126.276], post [1052.475 ± 126.276]; mean ± SE). CONCLUSION: Beta-band oscillations are often linked with various cognitive and motor functions. These results support a presence of contra-lateralization of the motor cortex with voluntary muscle activation patterns of the tibialis anterior during isometric contractions.



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