Effect of Neuromuscular Electrostimulation With Blood Flow Restriction on Acute Muscle Swelling of the Abductor Hallucis.

Context: Plantar intrinsic foot muscle strength training is difficult to master to a degree sufficient to elicit muscle hypertrophy in most individuals. It is possible that combining neuromuscular electrostimulation (NMES) and blood flow restriction (BFR) can elicit plantar intrinsic foot muscle hypertrophy regardless of the individual's technique. This study aimed to determine the effects of NMES training with BFR on acute muscle swelling in the abductor hallucis.

Design: Randomized, controlled, single-blind trial design.

Methods: Forty-eight participants were randomly allocated to the NMES + BFR, NMES, or Sham NMES + BFR groups. All participants received abductor hallucis NMES for 15 minutes. Participants in the NMES + BFR and Sham NMES + BFR groups received NMES with BFR. The intensity of NMES was the sensory threshold in the Sham NMES + BFR group. The cross-sectional area of the abductor hallucis was measured pretraining and posttraining using ultrasonography by a single investigator blinded to the participants' allocations.

Results: After 15 minutes of training, the cross-sectional area of the abductor hallucis was significantly increased in the NMES + BFR (P < .001) and the Sham NMES + BFR (P = .004) groups. Moreover, the rate of increase was significantly higher in the NMES + BFR group than in the NMES or the Sham NMES + BFR groups (P < .001 and P = .001, respectively).

Conclusions: Since it is possible that the amount of muscle swelling immediately after training correlates with muscle hypertrophy when training is continued, the results of this study suggest that NMES training with BFR is a training method that can be expected to produce plantar intrinsic foot muscle hypertrophy. Further studies are needed to confirm the long-term effects of NMES training with BFR.