Effects of Mid- and Low-Frequency Electromyostimulation for Prevention of Sarcopenia on Lower Extremity Muscles

Sarcopenia refers to the age-related reduction in muscle mass, decrease in muscle strength, and functional decline of muscles. Electromyostimulation is known to be effective in preventing sarcopenia by strengthening muscle strength. However, it is still controversial which is more effective for preventing sarcopenia, mid-frequency electromyostimulation or low-frequency electromyostimulation. Therefore, this study compared and analyzed the effects of mid- and low-frequency electromyostimulations on lower limb muscles. Forty subjects wore electromyostimulation pants and performed the prescribed exercise four times a week for 6 weeks. In this study, the subjects’ maximum voluntary contraction force, muscle activity while walking, and muscle frequency, muscle stiffness, and muscle decrement were measured once a week during the experiment. Through the experiment, the maximum voluntary contraction force, muscle frequency and muscle stiffness increased by 0.9%, 4.74%, and 4.74%, respectively, more using the mid-frequency electromyostimulation of 1000 Hz during exercise than using the low-frequency electromyostimulation of 62.5 Hz during exercise, but the muscle activity while walking and the muscle decrement decreased by 10.6% and 2.76%, respectively, more. In conclusion, since mid-frequency electromyostimulation is more effective in strengthening muscle strength than low-frequency electromyostimulation, it is expected to have an effect in slowing down or preventing the progression of sarcopenia. This study is considered to be used as the foundational data in relation to muscle strengthening to prevent sarcopenia in the future.