Whether looking for a tool to boost your fitness and strength or recover from an injury quickly, Electric Muscle Stimulation (EMS or NMES) can help you achieve your goal.

With that comes many questions, like what exactly is EMS/NMES? How about TENS units? This is a common question we get asked at events when we are demonstrating the Compex’s uses and benefits. To avoid further confusion, we want to clarify the differences between EMS/NMES (Electric Muscle Stimulation) and TENS (Transcutaneous Electrical Nerve Stimulation). Many people have been in physical therapy and may have had an experience with TENS and/or EMS devices, but were not educated on the difference between these types of stimulus.

Compex Muscle Stim


TENS and NMES target different nerve groups of the body. TENS specifically targets the sensory nerves (afferent nerve fibres), which are responsible for sending pain signals to the brain. NMES targets the efferent nerve fibres, specifically through the motor nerves, generating a muscular response as a consequence. This allows the NMES machine to create a muscle contraction to recruit more muscle fibers when training; warming up or recovering, and also to specifically recruit slow twitch or fast twitch muscle fibres according to your personal goal and/or sport/acitivity (due to the different frequencies used).

Sensory and motor nerves fire at different frequencies, which is why NMES and TENS devices affect the body differently.

TENS – Transcutaneous Electrical Nerve Stimulation

TENS is the use of an electrical current to stimulate the nerves for therapeutic purposes. TENS stimulates the sensory nerves, suppressing the pain signals that are being sent to the brain to give the user relief. In other words, TENS “tricks” the brain to ignore the pain for a short duration of time by applying a non-painful stimulus to the same area. 


NMES – NeuroMuscular Electrical Stimulation

NMES uses electric muscle stimulation (EMS) to cause excitement in the muscle tissue. This stimulus is designed to mimic the same type of signal the brain sends to the muscle when working out. There are two types of muscle fiber: slow twitch and fast twitch. Both muscle fibers contract at different frequencies. Compex Electric Muscle Stimulators offer various pre-programed settings which target the specific muscle types differently by adjusting the frequencies and work to rest cycles.The training settings are set to run in time intervals that depend on the goal of the muscle stimulus. For example, an Endurance Program will run at a lower frequency to target slow twitch fibers, have a longer contraction time and a shorter rest cycle. The more you increase the intensity of the Compex device, the more muscle fibers you recruit. This is how users see big strength gains, increases in vertical jump and reduce the risk for injury.



Check out our Compex Buying Guide and learn more about the different features, technologies, and programs.


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Compex is part of the DJO Global family,. DJO is multinational orthopedic medical device company and we can assist you to get and keep moving. From prevention to recovery, DJO Global enables people to live their lives to the fullest by providing intelligent medical technologies and services. #MotionIsMedicine