Effects of neuromuscular electrical stimulation of the knee extensor muscles on muscle soreness and different serum parameters in young male athletes: preliminary data

Abstract

To evaluate the effects of neuromuscular electrical stimulation (NMES) on muscle soreness and on a variety of serum parameters during and after NMES of knee extensor muscles of young, well trained subjects over a study period of 96 h. Five male cyclists were included in this clinical observation. NMES (biphasic, asymmetric impulses) was applied through surface electrodes to both knee extensor muscles of each subject for 30 min. To determine changes in serum concentration of muscle proteins, blood samples were drawn at defined measure points before and after NMES. Muscle soreness was evaluated using a visual analogue scale at all measure points. There was a maximum (p<0.05) for "muscle pain" during stimulation but no significant changes could be detected after the stimulation period. Serum creatine kinase showed a peak with a significant increase (p<0.05) 24 h after NMES. Serum lactate levels only increased slightly (p = 0.08) during NMES. Although the changes of blood parameters measured in the present work correspond to those reported in the literature on eccentric strength training, no delayed onset muscle pain could be detected. Further studies should be carried out, also investigating different stimulation protocols in non-trained healthy subjects and in patients with less muscle mass.