Electrical muscle stimulation explained

In recent years, training protocols have changed immensely due to the advances in science and technology providing more tools for individuals to improve their athletic capabilities. Where fractions of a second make the difference between success and failure, people will utilize all tools available to improve strength, endurance, speed and recovery as quick as possible. As a result, Electromyostimulation (EMS) has become extremely popular in providing individuals with this ability to perform and recover faster. EMS, also known as Neuromuscular Electrical Stimulation, is a technique by which an external device, placed on the surface of the skin, elicits muscular contractions using electrical impulses. These electrical impulses are generated from an electrical power unit (usually a battery) and provide an electrical current into the muscle using superficial pads that are placed on the skin. Specificity within placement of the pads is key as the current provided by the EMS device will only stimulate the motor units, which are motor neurons stimulating muscle fibers, that are beneath the pads to fire. It’s this electrical loop that is created by the EMS device and pad placement that allows the muscle to contract.

The applications of EMS are numerous and consist of:

1. Muscular rehabilitation and atrophy reduction
2. Muscular potentiation
3. Recovery tool and massage
4. Prevention of certain pathologies (DVT and Diabetes)

Firstly, EMS can be used for muscular rehabilitation and atrophy reduction. When injured, pain signals elicited from the site of injury inhibit individuals to contract muscles responsible for movement around that joint. As a result, muscle, which is a costly tissue to keep alive, will start breaking down within days to conserve energy from the bodies valuable stores. To prevent this from happening, medical professionals will often use an EMS device to stimulate these muscles and prevent them from wasting away when inactivity is present. As such, EMS is essential following surgical intervention to stimulate tissue repair and to prevent muscle wasting.

Secondly, EMS can be used as a muscular potentiation device to increase performance. Strength, which can be defined as the capacity to withstand great pressure or force, can be increased in one of two ways:

1. By increasing cross sectional area of muscle (Having bigger muscles)
2. By improving the efficiency of muscle contraction

EMS will have a direct effect by improving efficiency of muscle contraction by stimulating motor unit recruitment within the entire muscle using isometric contractions. In normal circumstances, the brain selectively chooses which fibers (found in muscle) will fire to be as energy efficient as possible. This process is called segmental muscle firing activation. In the case of EMS, the impulses created enable muscles to contract without any segmental firing pattern. As a result, a greater number of muscle fiber stimulation takes place as more motor units get stimulated. For this reason, athletes use EMS to improve strength and muscular contractile ability when applying it consistently within a training program.

Thirdly, EMS can be used as a recovery device by increasing blood flow to tissues. When performing strenuous physical activity, muscles used during that activity undergo numerous micro-tears after having been asked to perform heavy work. Furthermore, when insufficient amount of oxygen is present within the muscle, lactic acid is secreted increasing the acidity within the environment that muscles thrive in. This change in acidity leads to discomfort and soreness hindering muscle function. By stimulating muscle to contract using an EMS device, blood flow will be increased to the tissue needing oxygen post exercise. In addition, the increase in blood flow will provide more nutrients to foster repair and tissue regeneration. As EMS muscular contractions are unloaded (Therefore the muscles do not bear any weight), this will further speed up the recovery process.

Lastly, EMS can be used to prevent Deep Vein Thrombosis and help with circulation-based pathologies.  Given that an EMS device is worn regularly, blood clots (particularly in the leg) will have a decreased risk of being formed due to the increase in blood flow through arteries and veins. Diabetes patients can largely benefit from this by assuring that circulation is improved even when movement is not present.

To conclude, many EMS devices are currently found in the marketplace with travel size versions available for those out of town frequent flyers. The exact mechanism by which EMS improves strength, recovery and muscle tone reduction is not fully known but more research is currently being done to find out. To those skeptical about EMS, give it a try and see what you think, you may benefit from it more than you think!

Oliver L.