What is Neuromuscular Electrical Stimulation (NMES)?
NMES uses small electrodes applied to the skin to apply a series of stimuli to the muscles underneath which causes them to contract and relax.
How Does NMES work?
Normally, during voluntary muscular contraction, the brain sends an electrical impulse along the nerves responsible for movement to tell the muscles to contract. The electrical impulse causes a chemical reaction to occur where the nerve cells meet the muscle fibres, which allows the muscle to shorten. When this electrical impulse stops so does the contraction and so the muscles relax.
With NMES, the electrodes applied to the skin replicate this impulse by sending electrical stimuli to excite the nerve branches within the muscles which therefore cause muscular contraction underneath the electrodes.
It is important to note that muscles are made up of numerous motor units. Motor units consist of a nerve cell which communicates with a group of muscle fibres which can either be slow or fast twitch. Slow twitch fibres are used in all types of activity but are dominant in endurance type exercise whereas fast twitch fibres are useful for movements or exercises that require power or bursts of speed e.g. sprinting. Normally during exercise, slow twitch fibres are recruited first before fast twist fibres become involved. However, NMES is slightly different to normal resistance exercise as it recruits both slow and fast twitch fibres right from the start even when stimuli levels are low. This makes NMES particularly useful when rehabilitating athletes who participate in sports that involve powerful movements. However, the level of muscular contraction depends on the level of electrical stimuli being applied and this is controlled through the unit to which the electrodes are attached.
When can NMES be used?
As previously mentioned NMES is particularly useful for those athletes who are undergoing rehabilitation, however this is not the only population group that may benefit. The NMES unit can be used in a number of different ways depending on the goal of the patient.
NMES can be used to help prevent loss of muscle mass and function during periods of immobility, for example after surgery.
Examples of areas that can utilise NMES include the following:
However, it is important to note that NMES may not be suitable for everyone and is not advised in people who have pacemakers, internal defibrillators or a sensory deficit that may not allow them to feel the effect of the electrodes. Additionally, although NMES is a beneficial tool, normal exercise within the persons limits should still be performed to gain improvements in daily function and sporting activities.
If you think NMES is a treatment that may benefit yourself and you would like some more information, please do not hesitate to contact the clinic through either email or by telephone.
Please note the above information was kindly researched and written by our physiotherapy student, Anna Fraser.