Definition
Neuromuscular and muscle electrical stimulation (NMES) is a method of sending electrical impulses to nerves, causing muscles to contract, mimicking action potentials from the central nervous system. It can be applied during or without functional movement. it It has been used for many years to strengthen and maintain muscle strength and prevent atrophy, especially in immobilized patients [1].
Indications
- Improve muscle strength and prevent muscle atrophy
- Improve and maintain range of motion around joints
- Reduce muscle spasms and spasms
- Enhance cardiovascular function through activity of large muscle groups [2]
Contraindications
- when placed over the carotid sinus
- when the patient has a pacemaker
- When we have active areas of tissue infection and inactive skin
- When patients are unable to understand instructions and provide feedback
- when the patient is pregnant
- When the patient has peripheral vascular disease [3]
Electrically stimulated muscle contraction vs. physiological muscle contraction
Two major differences between electrically stimulated muscle contraction and physiological muscle contraction are the sequence of motor unit recruitment and the smoothness of contraction onset. During normal physiological muscle contraction, the first fibers recruited are Slow-twitch type 1 fibers, followed by large-diameter fibers, which produce low-force contractions, are fatigue- and atrophy-resistant, and contract smoothly. In contrast, during electrically stimulated muscle contraction, the first muscle fibers recruited are The large-diameter fast-twitch type 2 muscle fibers that produce the strongest and fastest contractions fatigue and atrophy rapidly and produce jerky movements, which is why electrical stimulation of NMES should provide longer rest periods between stimulated contractions[ 4].
Application of NMES
First, the patient should sit comfortably and allow the muscles to relax, which is necessary to stimulate the muscles more easily. The skin should then be checked to make sure there are no skin abrasions and injuries. Then clean the skin properly with a cloth and water or alcohol-based wipes, it is important to ensure that the skin is completely dry before applying the electrodes to the skin.
A wide variety of electrodes can be used, including self-adhesive electrodes, which are quick and easy to apply because they already have a layer of conductive material on their surface, unlike carbon rubber electrodes, which are usually attached to the skin through an electrically conductive gel. These electrodes should be placed away from the joint and properly attached to the skin to avoid pain and discomfort. These electrodes can be placed in such a way that the cathode is placed on the motor point of the target muscle and the anode is placed proximally on a nearby muscle supplied by the same muscle Nerves, this placement is called monopolar electrode placement and is used when targeting small muscles. Bipolar electrode placement involves placing two electrodes either on the muscle belly or one proximal and the other distal to the muscle. The size of the electrode depends on The size of the muscle or muscle group to be stimulated, where stimulation of muscles such as the quadriceps or hamstring muscles requires large electrodes [5].
During electrical stimulation, it is important to gradually increase the stimulation intensity to the maximum that the patient can tolerate. For innervated muscles, generally the shorter the pulse duration, the larger the pulse amplitude should be, while for denervated muscles, both The pulse duration and pulse amplitude should be greater than that of the innervated muscle, which is especially important to ensure the stimulation and sudden contraction of the muscle [6].
[7]
Parameters
- Frequency (Hz) is the number of pulses in one second (20-50 pulses per second)[8]
- Pulse duration (microseconds) is approximately 150-200 for small muscles and 200-300 for large muscles
- Ramp time is at least 2 seconds
- ON: The OFF time scale should be set so that the OFF time is three times the ON time
- Treatment time should be between 20 and 30 minutes
- The frequency of meetings should be 3 times a week[5]
References
- ↑ Hainaut KH. Duchateau JD. Neuromuscular Electrical Stimulation and Voluntary Exercise.Sports Med. 1992;14(2):100-13.
- ↑ The Association of Paediatric Charted Physiotherapists. Publications. Available from: https://apcp.csp.org.uk/content/guide-use-electrical-stimulation-paediatric-neurodisabilityn (accessed 18/12/2022)
- ↑ Lago AL. Oliveira AO et al. The Effects of Physical Therapy with Neuromuscular Electrical Stimulation in patients with Septic Shock: Study Protocol for a Randomized Cross-Over Design. Medicine. 2018; 97(6).
- ↑ Barss TB., et al. Utilizing physiological principles of motor unit recruitment to reduce fatigability of electrically-evoked contractions: a narrative review. Archives of physical medicine and rehabilitation. 2018;99(4):779-791.
- ↑ Jump up to:5.0 5.1 Nussbaum EN., et al. Neuromuscular electrical stimulation for treatment of muscle impairment: critical review and recommendations for clinical practice. Physiotherapy Canada. 2017; 69(5): 1-76.
- ↑ Gorgey AG. Dudley GD. The role of pulse duration and stimulation duration in maximizing the normalized torque during neuromuscular electrical stimulation. Journal of Orthopaedic & Sports Physical Therapy. 2008;38(8): 508-516.
- ↑ PhysioU. How to prepare for Neuromuscular Electrical Stimulation (NMES)?. Available from: https://www.youtube.com/watch?v=_eBUskzKaPI [last accessed 12/18/2022]
- ↑ Baldwin EB., et al. Wide-pulse-width, high-frequency neuromuscular stimulation: implications for functional electrical stimulation. Journal of Applied Physiology. 2006; 101(1):228-240.
