EMS means “electric muscle stimulation”.
Electric Muscle Stimulation(EMS) induces muscle contraction with the help of electric current. Such contraction is different than the one induced by traditional training controlled by the central nervous system. In the motor neuron (action potential) the stimulus induced by either the nervous system or the electric impulse is the same. Hence, muscle resistance will be similar when stimulated to the same extent.The muscle, in fact, cannot distinguish whether the stimulus was induced by the nervous system or an electric impulse. The nature and intensity of the stimulus depend on the parameters configurated on the device.
To put it simply, the EMS device is able to achieve what the human brain cannot. While the brain is capable of stimulating a big part of the muscle fibers, the EMS device stimulates nearly 100%. This means a much greater synchronization of the fibers. Furthermore, unlike the human brain, an EMS device sends out con- sequent and quality impulses to the muscles, without overloading the cardiovascular system, or causing psychical fatigue. This leads to better and safer performance growth than in the case of individually pursued traditional training methods.
Electric impulse provides the tools for engaging the muscles. This impulse is transmitted from the EMS device through the neurons and motoneurons to the muscle. Its role is to induce muscle motion. This mechanic response is what we call a ‘twitch’.Every time an electric impulse is repeated, it induces a muscle twitch. When the muscle is stimulated by frequent impulses, if there is not enough time for a twitch to end before the next one is induced, muscle fibers will reach the state of contraction. In this case, the muscle’s response is a full contraction. This is called a tetanic contraction.If the stimulation frequency (the number of stimulations per second) increases, individual twitches become less and less distinguishable, until reaching a point where muscle contraction occurs. High frequency (above 100-150Hz) is hardly noticeable because the muscle is unable to respond to these too quick impulses.
The quality and quantity of the work done by the muscle depend on the configured parameters, and the intensity applied (adequately placed electrodes are also a factor). These parameters are the following:
- the intensity of the electric impulse stimulating the motor neuron
- impulse frequency (Hz), which indicates the number of impulses per second
impulse interval, which indicates the duration of the impulse pause interval, which indicated the duration between two impulses
- impulse depth, indicating the depth where the impulse reaches the musculature the number of repetitions indicates the number of repeated impulses
Intensity (mA) is not pre-configured; it can be manually set with the intensity control button (master) after the device is turned on. The number of muscle fibers involved in the training depends on the level of intensity. The greater the intensity the more muscle fibers are activated. Only those muscle fibers will work and develop that have been stimulated by EMS. If intensity is low, very few muscle fibers are recruited, which slows down development.