慢性足関節不安定症患者における高密度経頭蓋直流電気刺激とバランスボールトレーニングの併用による皮質活性化の向上と足関節機能の改善：ランダム化比較試験

This study explored the effects of High-definition transcranial direct current stimulation (HD-tDCS) with Bosu-ball training on cortical activation and ankle-foot function among individuals with chronic ankle instability (CAI).

Single-blind randomized sham-controlled trial.

Biomechanics laboratory.

Thirty-seven participants were allocated to tDCS+Bosu group (n=19) and Bosu group (n=18), received 6-week active or sham HD-tDCS with Bosu ball training. Change values of oxyhemoglobin concentration (ΔHbO2) and Foot and Ankle Ability Measure (FAAM) were measured pre- and post-intervention. Two-way analysis of variance and Pearson correlation analysis were applied.

We detected significant group-by-time interactions in ΔHbO2 for the affected and non-affected side premotor cortex and supplementary motor area (PMC & SMA, channel 4: P=0.048; channel 14: P=0.047) and the affected side primary motor cortex (M1, channel 6: P=0.049), and significant time effects for the affected and non-affected side PMC & SMA (channel 2: P=0.043; channel 12: P=0.047), M1 (channel 5: P=0.041; channel 15: P=0.027; channel 16: P=0.049), primary somatosensory cortex (S1, channel 7: P=0.039; channel 17: P=0.043) and somatosensory association cortex (SAC, channel 8: P=0.021; channel 19: P=0.035). We detected significant interaction in the FAAM Sports subscale (P=0.046), and significant time effect in the FAAM Activities of Daily Living subscale (ADL subscale) (P<0.001). The increments in ΔHbO2 of channels 4, 5, 16, 19 were moderately positively correlated with the increment in scores of the FAAM Sports subscale (P=0.015, P=0.006, P=0.008, P=0.003). The increment in ΔHbO2 of channel 7 was weakly positively correlated with the increment in scores of the FAAM Sports (P=0.049) and ADL subscales (P=0.038).

Bosu-ball training increased cortical activation and improved ankle-foot function among individuals with CAI, and yielded more improvements with active HD-tDCS. The increment of cortical activation was positively correlated with the improvement of ankle-foot function.