E.M.S. stands for Electrical Muscle Stimulation. EMS is predominately used by doctors and physical therapists to prevent, or reduce, muscle atrophy. Atrophy is the weakening and loss of muscle tone, which is usually experienced after surgeries or injuries. EMS has proven to be an effective means of preventing muscle atrophy. Doctors also see EMS as a means of increasing blood flow to muscles, increasing range of motion, increasing muscle strength, as well as enhancing muscle endurance. EMS will have pain management attributes in regards to muscle related pain, such as a spastic muscle, sore muscles, or tight muscles. A TENS device is more suited for nerve related pain conditions (acute and chronic conditions).
While using the EMS, the brain sends a nerve impulse to the "motor point" of your muscle. This signal is a message to the muscles to expand and contract. Electrodes are placed over the motor points of the muscle group to be exercised. When the stimulation is applied through the pads, the signal finds its way to these motor points and causes the muscle to expand and contract. This makes it possible to duplicate a conventional exercise, similar to an isometric exercise.
During an exercise, your brain sends a message down the spinal cord through the nerves with all the muscles you're using that causes them to relax and contract. This is called voluntary muscle action. Your brain is controlling the muscle.
Electrical muscle stimulation uses an outside electrical source that stimulates the nerves to send signals to your muscle to expand and contract. This is done by sending electrical current through self adhesive electrodes placed over the muscle. The current passes through your skin to the nerves in that area, causing the muscle to expand and contract.
Studies have shown that EMS stimulates large nerve axons (long outgrowths of a nerve cell body), some of which you cannot stimulate voluntarily. It is possible that EMS might allow for additional muscle hypertrophy (increased development of tissue by enlargement, without multiplication of cells).
EMS can increase muscle hypertrophy (growth), endurance and strength. EMS may be used only for this or with regular weight training by aiding recovery and helping muscles grow and get stronger. EMS can increase body temperature, heart rate and metabolism (promoting energy and fat absorption from the body).
This type of stimulation is characterized by a low volt stimulation targeted to stimulate motor nerves to cause a muscle contraction. EMS differs from TENS in that it is designed to stimulate muscle motor nerves, while TENS is designed to stimulate sensory nerve endings to help decrease pain.