Electrical stimulation for build muscle?

Patient: Back when I was 22 some friends had a “shock box” at a party. It’s a small box with a 6v battery and 2 metal rods. You grab a metal rod in each hand and someone turns the dial from 0 to 9 for differing intensities. Well, I did it, and of course they turned it up to 9. The current was strong enough to contract all my muscles in my body, I was on my tip toes and try as I might to throw the rods down, my hands wouldn’t open until they dialed it back down to 0 about 5 seconds later. I remember I was a little weak directly after, but nothing bad at all. The next day every muscle in my body ached like they do the day after wakeboarding for a full day. I was in great shape back then, so it normally took quite a workout for my muscles to feel sore even a little.So here’s my questions. Since then I’ve been wondering if one could use this method say once or twice a week to actually build muscle? What would be the negative affects for long term use? I’m wondering if electrical current even this small could affect the brain and thought process, memory, etc.

Doctor: The Electronic Muscle Stimulation (EMS) works providing an low level electrical stimulus that fires all motor neurons si multaneously in the area where is placed, this creates an uncoordinated contraction that may exhaust the muscle fibers the in few seconds. It is used mainly in rehabilitation therapy. The EMS works directly on the muscles and bypasses the body’s energy conservation system and also is very different regarding the voluntary muscle contraction and the selective recruitment of different types of motor neurons, meaning muscles work their individual fibers in relays, always holding some back from even the most demanding load to maintain a reserve. Therefore, it’s impossible to voluntarily contract all fibers simultaneously. Yes, you could use it to build muscle in a targeted area but this method is not enough by itself to bodybuilding muscles, it has to be combined with a Healthy diet, adequate hydration, stretching routine.