EMS means Electrical Myo Stimulation (5 to 100 Hz) , EMA means Electrical Myo Activation (from 1,000 Hz). In EMS training, the current flows from the electrode through the skin to the nerve and then into the muscle. In EMA training g, the current flows from the electrode through the skin directly into the muscle without the nerves being aware and without the signal having to pass through the neuromuscular endplate between the nerve and muscle on its way to the muscle. This direct muscle activation can be interesting and dangerous at the same time, and is therefore not recommended for home use in our view.