Microcurrent treatment promotes force recovery from high-intensity eccentric contraction-induced muscle damage in human skeletal muscle: a prospective double-blind randomized control study

BACKGROUND: Microcurrent electrical neuromuscular stimulation (MENS) treatment has been shown to be effective for tendon inflammation and refractory skin and bone lesions. This study investigated the effects of the commonly used MENS treatment on muscle function and soreness in human skeletal muscles subjected to high-intensity eccentric contraction (ECC).METHODS: Fifteen untrained young men (20.5±1.0 years) performed 50 maximal ECCs of the elbow flexors of one arm. The participants were divided into placebo (N.=7) and MENS (N.=8) groups. Contractile properties assessed by tensiomygraphy, maximal voluntary contraction (MVC) torque, serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities, and muscle soreness assessed by a visual analogue scale were measured immediately before ECC, and immediately, 1, 3, and 6 days after ECC. Participants in the MENS group received MENS treatment for 20 minutes immediately, 1, 2, 3, 4, 5, and 6 days after ECC. Changes in these variables over time were compared using two-way repeated-measures ANOVA.RESULTS: Immediately after ECC, MVC torque was reduced by approximately 50% in both groups. The MVC torque and muscle soreness returned to pre-ECC levels only in the MENS group. ECC resulted in a decreased contraction velocity and increased serum CK and LDH activities. However, changes in these parameters over time were similar between the two groups.CONCLUSIONS: The commonly used MENS treatment is an effective strategy for facilitating force recovery and alleviating muscle soreness in skeletal muscles subjected to ECC.