Neuromuscular Electrical Stimulation (NMES) uses regulated electrical impulses to engage nerves and elicit muscle contractions. This non-invasive approach aims to improve muscle strength, enhance range of motion, and mitigate muscle wasting, supporting muscle function and recovery.
How NMES Works
NMES operates by delivering precisely controlled electrical impulses through electrodes placed on the skin, over a targeted muscle group. These impulses travel through the skin and stimulate underlying motor nerves, which send signals from the brain to the muscles. When these motor nerves receive the electrical signal, they trigger an involuntary contraction of the associated muscle fibers.
This induced contraction mimics the natural process of muscle activation initiated by the brain, bypassing the voluntary command system. The sustained contractions help re-educate muscles that may have become inactive or weakened due to injury or disuse. Regular application of these electrical stimuli can also prevent muscle atrophy.
Conditions Treated with NMES
NMES is used in rehabilitation and recovery. It is employed following surgical procedures, such as knee surgeries, to help patients regain strength and control in the affected limb. The controlled contractions assist in reactivating muscles inhibited by pain or swelling, accelerating the return to normal function.
The therapy is also used for individuals experiencing general muscle weakness, whether from prolonged inactivity or certain medical conditions. In neurological injuries like stroke or spinal cord injury, NMES can address conditions such as foot drop. By stimulating the muscles responsible for lifting the foot, it helps improve gait mechanics and prevent tripping. NMES can also maintain muscle mass during periods of prolonged immobility, such as bed rest or casting, by providing regular muscle activation.
What to Expect and Important Considerations
During an NMES session, individuals experience a sensation ranging from a tingling feeling to a noticeable muscle twitch or strong, visible contraction. The intensity depends on the electrical current delivered and the individual’s tolerance level. A healthcare professional will adjust therapy parameters, including impulse frequency, pulse duration, and intensity, to suit the specific muscle group and patient comfort.
Before beginning NMES, a healthcare provider, such as a physical therapist, assesses an individual’s condition to ensure its appropriateness. Contraindications exist where NMES should not be used. These include:
Presence of a pacemaker or other implanted electronic devices.
Pregnancy.
Certain active skin conditions or open wounds in the treatment area.
Active infections.
Areas with recent or specific nerve damage.
While generally safe, minor adverse effects can occur, such as muscular discomfort during or after a session, or temporary skin irritation beneath the electrodes. Professional guidance from a healthcare provider is important to ensure correct electrode application and appropriate therapy settings. This guidance helps maximize therapeutic benefits while minimizing potential risks. Although some NMES devices are available for self-administration, professional consultation is always recommended to determine if the therapy is suitable and to receive proper training on its safe and effective use.