NeuroRehab Team
Thursday, July 23rd, 2026
Electrical StimulationElectrode Placement
Neuromuscular electrical stimulation (NMES) is one of the most well-researched tools available for upper limb recovery after stroke. Multiple clinical trials have demonstrated its effectiveness for improving motor function in the shoulder, elbow, wrist, and hand. But the results depend heavily on one thing that is rarely explained in enough detail: where you place the electrodes.
Incorrect electrode placement produces weak or absent muscle contractions, stimulates the wrong muscles, or causes discomfort without therapeutic benefit. Correct placement produces strong, comfortable contractions of the target muscle that, combined with active attempt at voluntary movement, drive the neuroplastic changes that support motor recovery.
This guide covers electrode placement for every major upper limb muscle group affected by stroke, with step-by-step instructions for each site. For a broader overview of electrical stimulation for stroke recovery including device settings and protocols, see our complete electrode placement guide for stroke recovery.
Before covering placement, it helps to understand what NMES is doing and why correct placement matters so much.
NMES delivers electrical impulses through electrodes placed on the skin over a target muscle. The electrical current passes through the skin and stimulates the motor nerve supplying the muscle, causing it to contract. In stroke survivors, this is particularly valuable because the brain can no longer reliably send the signals needed to produce voluntary contraction. NMES bypasses the damaged pathway and directly activates the muscle.
The neuroplastic benefit of NMES comes from the combination of the electrical stimulus and the survivor’s simultaneous active attempt at voluntary movement. When both occur at the same time, the brain receives sensory feedback from the contracting muscle while simultaneously attempting to generate the movement. This combination strengthens the neural pathway between the motor cortex and the muscle far more effectively than either passive electrical stimulation or attempted movement alone.
This is why correct electrode placement is critical. If the electrodes are not positioned over the right muscle, the contraction produced will not be the movement the survivor is attempting, the sensory feedback will not match the motor intention, and the neuroplastic benefit will be significantly reduced.
These principles apply to every electrode placement site covered in this guide:
Skin preparation. Clean the skin with a mild soap and water or an alcohol wipe before placing electrodes. Oil, lotion, and dead skin cells increase resistance and reduce the quality of stimulation. Allow the skin to dry completely before placing electrodes.
Electrode size. Smaller electrodes produce more focused stimulation. Larger electrodes distribute the current more broadly and are more comfortable at higher intensities. For most upper limb applications, electrodes between 2cm x 2cm and 4cm x 5cm are appropriate. Use the smallest electrode that produces a good contraction without discomfort.
Electrode orientation. For most muscles, electrodes should be placed along the length of the muscle belly, with one electrode over the motor point (the point at which the motor nerve enters the muscle and stimulation produces the strongest contraction) and one electrode over the distal portion of the muscle or its tendon.
Intensity settings. Start with a low intensity and increase gradually until a visible muscle contraction is produced. The contraction should be strong enough to produce visible movement but not so strong that it causes pain or discomfort. A good therapeutic contraction feels like a strong pull rather than a sharp pain.
Always attempt voluntary movement. During every NMES session, actively attempt to produce the target movement yourself as the stimulation fires. This is the single most important factor in maximising the neuroplastic benefit of the treatment.
Skin monitoring. Check the skin under and around the electrodes after every session. Mild redness that fades within 30 minutes is normal. Persistent redness, skin irritation, or burns indicate that intensity is too high, electrodes need repositioning, or skin preparation needs to improve.
Weakness in shoulder flexion and abduction limits the ability to reach overhead and forward, which affects almost every functional upper limb task. The primary muscle for shoulder flexion is the anterior deltoid. The middle deltoid drives shoulder abduction.
Electrode positions for anterior deltoid (shoulder flexion):
Electrode positions for middle deltoid (shoulder abduction):
External rotation weakness is extremely common after stroke and contributes to the internally rotated shoulder posture that limits functional reach and can contribute to shoulder pain and subluxation. The primary external rotators are the infraspinatus and teres minor, both located on the posterior surface of the scapula.
Electrode positions for external rotation:
For survivors with shoulder subluxation, stimulating the supraspinatus and posterior deltoid may help support the shoulder joint and reduce the degree of downward displacement.
Electrode positions for supraspinatus and posterior deltoid:
Elbow flexor spasticity is one of the most common upper limb problems after stroke, producing a bent elbow posture that limits reach and functional use of the arm. Stimulating the triceps to produce elbow extension both stretches the spastic flexors through reciprocal inhibition and helps restore the motor pathway for active extension.
Electrode positions for triceps (elbow extension):
Wrist drop, where the wrist hangs in a flexed position due to weakness of the wrist extensors, is one of the most functionally limiting upper limb deficits after stroke. NMES for wrist extension is one of the most extensively researched applications in stroke rehabilitation and has consistently demonstrated effectiveness for improving wrist extension strength and functional hand use.
Electrode positions for wrist extensors:
In some survivors, particularly those working on functional grip and release, stimulating the wrist flexors as well as the extensors in alternating fashion can help restore more balanced wrist control.
Electrode positions for wrist flexors:
Finger flexor spasticity producing a clenched fist is one of the most common and functionally limiting upper limb problems after stroke. Stimulating the finger extensors helps open the hand, reduces flexor spasticity through reciprocal inhibition, and supports the neuroplastic recovery of voluntary hand opening.
Electrode positions for finger extensors:
Thumb adductor spasticity, where the thumb is pulled into the palm, significantly limits pinch grip and functional hand use. Stimulating the thumb abductors and extensors helps restore thumb position and supports functional grip recovery.
Electrode positions for thumb abduction:
Electrode placement is only one component of effective NMES treatment. The following protocol recommendations are based on current clinical evidence for upper limb stroke rehabilitation:
| Parameter | Recommended range | Notes |
|---|---|---|
| Pulse frequency | 30 to 50 Hz | Higher frequencies produce stronger contractions but fatigue faster |
| Pulse width | 200 to 400 microseconds | Wider pulse width recruits more muscle fibres |
| On time | 5 to 10 seconds | The period of stimulation during which the muscle contracts |
| Off time | 10 to 20 seconds | Rest period between contractions. Ratio of at least 1:2 on:off reduces fatigue |
| Session duration | 30 to 60 minutes | Longer sessions produce more repetitions and greater neuroplastic stimulus |
| Frequency | Once to twice daily | Daily use produces better outcomes than 2 to 3 times per week |
| Duration of program | Minimum 4 to 6 weeks | Research shows cumulative benefits over weeks and months of consistent use |
Placing electrodes over bony prominences. Electrodes placed directly over bone produce uncomfortable stimulation with poor muscle activation. Always place electrodes over the muscle belly, not over bony landmarks.
Using electrodes that are too small for high-intensity stimulation. Very small electrodes concentrate the current in a small area, which increases the risk of skin irritation and discomfort at higher intensities. If you need high intensity to produce a good contraction, try slightly larger electrodes.
Passive use without voluntary effort. Using NMES as a passive treatment while watching television or resting produces limited neuroplastic benefit. The combination of electrical stimulation and simultaneous active voluntary effort is what drives motor recovery. Always attempt the target movement as the stimulation fires.
Inconsistent use. NMES produces cumulative benefits over time. Using it occasionally when it is convenient produces far less benefit than using it consistently every day as part of a structured routine. Treat your NMES sessions like medication: same time each day, every day.
Stopping too soon. Many survivors stop using NMES after a few weeks because they do not see dramatic immediate results. Research consistently shows that meaningful neuroplastic changes accumulate over weeks and months of consistent use. If you are not seeing results after two weeks, check your placement and intensity settings before concluding that NMES is not working for you.
The clearest sign of correct placement is a strong, visible contraction of the target muscle producing the intended movement. For wrist extension placement, you should see the wrist lift upward. For finger extension, you should see the fingers open. If you are getting stimulation sensation but no clear movement, the electrodes may be off the motor point. Move them slightly and reassess until you find the position that produces the strongest contraction.
NMES is generally contraindicated in people with pacemakers or other implanted electrical devices. The electrical current can interfere with the device. Always consult your cardiologist or GP before using NMES if you have any implanted electrical device.
Most research protocols run for four to six weeks minimum before assessing outcomes. Some survivors notice improvements in voluntary movement within the first two to three weeks of consistent daily use. Others see changes more gradually over two to three months. Consistency of use is the strongest predictor of response. If you are using NMES correctly and consistently and seeing no change after six weeks, discuss it with your rehabilitation team.
For most stroke survivors with upper limb spasticity, stimulating the extensors (triceps, wrist extensors, finger extensors) is the priority. Extensor stimulation produces voluntary-like movement that opposes the spastic flexor posture, reduces flexor tone through reciprocal inhibition, and supports the functional movements needed for reach and hand opening. Flexor stimulation may be added later to work on grip strength once some extensor function has returned.
Yes. NMES has demonstrated effectiveness for upper limb motor recovery in chronic stroke survivors, including those more than 12 months post-stroke. Neuroplasticity does not have an expiry date and the mechanisms by which NMES supports recovery remain active regardless of how long ago the stroke occurred. Consistent daily use in the chronic phase continues to produce meaningful benefits.
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