Can NMES Reach the Lumbar Multifidus? Electrical Stimulation, Electrode Placement & Device Selection
Quick answer: Yes. Surface neuromuscular electrical stimulation (NMES) has been shown in ultrasound studies to produce measurable activation and thickening of the lumbar multifidus in some people. However, a surface stimulator cannot guarantee selective recruitment of the deepest multifidus fibers. Electrode position, pulse characteristics, stimulation intensity, individual anatomy, and tolerance all determine which lumbar muscles are recruited.
If the goal is to activate the multifidus rather than simply produce a sensory tingling sensation for temporary pain modulation, NMES/EMS is the relevant modality—not conventional TENS alone. Balego already has a detailed TENS-versus-NMES resource, so there is no need to duplicate that discussion here. Read Balego's TENS vs. NMES guide
This article instead addresses the more specific question: Can stimulation delivered through the skin recruit the lumbar multifidus, and what should clinicians and patients look for in a device?
What Is the Lumbar Multifidus?
The multifidus consists of relatively small muscles running along the posterior spine. In the lumbar region, its fibers contribute to segmental control and spinal stability.
Because portions of the lumbar multifidus lie beneath more superficial paraspinal tissue, it is reasonable to question whether stimulation from electrodes placed on the skin can actually “reach” the muscle.
The word "reach," however, can be misleading.
Surface NMES does not send current exclusively into one anatomically isolated muscle. Electrical current passes through the skin and underlying tissues and stimulates excitable motor nerves. The resulting contraction can involve the multifidus, but nearby lumbar paraspinal muscles can also be recruited.
The more clinically useful question, therefore, is the following:
Does the multifidus itself show measurable activation when lumbar NMES is applied?
Research indicates that it can.
Can Surface NMES Actually Activate the Multifidus?
Several studies have measured multifidus activity during electrical stimulation using rehabilitative ultrasound imaging.
| Research | What Was Tested | Finding | Practical Significance |
|---|---|---|---|
| Sions et al., 2019 | 60 adults with chronic low-back pain receiving lumbar surface NMES | Multifidus thickening occurred during NMES; greater tolerated intensity was associated with greater thickening | Direct evidence that transcutaneous NMES can recruit lumbar multifidus |
| Baek et al., 2014 | Lumbar paraspinal NMES at 20, 50, and 80 Hz | Both superficial and deep multifidus thickness increased | Surface stimulation can activate deeper stabilizing tissue |
| Songjaroen et al., 2021 | NMES combined with motor-control exercise | Combined treatment improved lumbar multifidus activation compared with motor-control exercise plus sham stimulation | Supports NMES as an adjunct to active rehabilitation |
| Vardar et al., 2025 | Lumbar stabilization exercise with or without NMES | Multifidus thickness increased in both groups but more prominently with adjunct NMES | Adds randomized evidence supporting NMES plus exercise |
The 2019 investigation is particularly useful because it describes the stimulation setup in detail. Four self-adhering 2 × 2-inch electrodes were positioned over the paraspinal muscles at approximately the L2 and S1 levels bilaterally. Ultrasound imaging of the L4/L5 multifidus was then performed between those electrode positions. The device delivered symmetrical biphasic pulsatile stimulation at 50 pulses per second with a 400 µs pulse duration.
That does not mean these settings should automatically be copied into a home treatment program. They describe a controlled research procedure in which clinicians were observing the actual muscle response with ultrasound.
How Deep Can Surface NMES Stimulate?
This is where the answer needs some nuance.
A 2014 ultrasound study specifically examined the effect of transcutaneous stimulation over the lumbar paraspinal region and found that NMES increased the thickness of both superficial and deep lumbar multifidus. The investigators tested 20, 50, and 80 Hz stimulation.
That provides substantial evidence against the idea that surface electrical stimulation necessarily affects only the superficial back muscles.
It does not, however, prove that surface NMES selectively isolates the deepest multifidus fibers.
The electrical field can also activate neighboring erector spinae and other stabilizing muscles. Subcutaneous tissue thickness, electrode spacing, motor-point location, skin resistance, body position, and the stimulation amplitude all influence recruitment.
Therefore, the phrases “the patient's low back visibly contracts” and “the patient's deep multifidus is being selectively recruited” do not necessarily refer to the same phenomenon.
What Electrode Placement Has Actually Been Studied?
The Sions study used four 2 × 2-inch electrodes positioned bilaterally over the paraspinal muscles at L2 and S1. The L4/L5 region remained between the electrodes so researchers could image the multifidus with ultrasound.
This is particularly relevant because the company carries 2-inch-square reusable stimulation electrodes—the same general electrode dimension used in that study. Balego 2-inch TENS/NMES/FES electrodes: Our electrodes are available in 2-inch square as well as larger rectangular and round configurations.
That does not make any electrode setup automatically equivalent to the research protocol. Electrode size is only one variable.
Pads should generally be placed over appropriate soft tissue rather than directly on the bony spinal midline, and the individual device's labeling and clinician instructions should always take precedence.
Does NMES Intensity Matter?
Apparently, yes—but this is another area where the research should not be converted into a universal prescription.
In the 2019 study, multifidus thickening initially became detectable in roughly the low-30 mA range on average. Participants who could tolerate higher intensities generally demonstrated more multifidus thickening.
The higher-tolerance group averaged approximately 62 mA at the higher tested stimulation level and demonstrated about 30.9% multifidus thickness change, while the lower-tolerance group averaged approximately 45 mA and about 20.6% thickness change.
The useful lesson is the following:
Motor recruitment requires enough stimulation to create an effective contraction.
The lesson is not that everyone should set a portable unit to 45, 60, or 62 mA.
Milliamp readings cannot be treated as perfectly interchangeable between different devices, electrode sizes, waveforms, loads, and individuals.
TENS or NMES for Multifidus Activation?
If the objective is simply temporary sensory-level pain modulation, TENS may be appropriate when clinically indicated.
In contrast, NMES is the more relevant modality when the goal is to deliberately activate the multifidus or lumbar-paraspinal muscles.
| Goal | TENS | NMES |
|---|---|---|
| Sensory stimulation | Yes | Can occur |
| Temporary pain-modulation program | Primary role | Secondary consideration |
| Deliberate muscle contraction | Usually not. | Yes |
| Multifidus motor recruitment | Not the primary purpose | Relevant modality |
| Work/rest contraction cycles | Generally unnecessary | Important |
| Neuromuscular re-education | No | Potential role |
We already explained the broader distinction on its TENS-versus-NMES page, while its NMES section focuses specifically on contraction-based electrical stimulation. Explore Balego NMES devices
Which device is best suited for multifidus NMES?
Rather than reproducing every specification from Balego's existing product pages, it is more useful to compare only the characteristics relevant to this specific question.
| Device | Multifidus-Relevant Features | Best Fit | Limitation |
|---|---|---|---|
| InTENSity Select Combo II DI2195 | NMES 200–400 µs; TENS/NMES output to 100 mA; adjustable rate; symmetrical biphasic rectangular waveform; low-back program group and custom settings | Best overall portable feature match | A low-back preset is not a validated multifidus protocol |
| Chattanooga Intelect NMES Digital 77717 | Dedicated NMES; 0–80 mA at 500Ω; 2–120 Hz; 50–300 µs; programmable work/rest and ramp | Best dedicated clinician-focused NMES option | Does not reach the 400 µs pulse width used in the 2019 study |
| Balego EMS Digital NMES | Dedicated dual-channel NMES; adjustable rate, width, ramp and contraction/rest timing | Best value-focused dedicated NMES approach | No surface unit can promise selective deep multifidus isolation |
| Richmar Twin Stim Plus DS5402 | Four independent channels; up to eight electrodes; EMS/NMES, IF, and Russian; EMS 2–150 Hz and 50–300 µs | Best for broader bilateral/multi-electrode clinic setups | More channels do not automatically create deeper stimulation |
Why the InTENSity Select Combo II Is Particularly Interesting
Among portable options, the InTENSity Select Combo II DI2195 has the strongest technical alignment with the commonly cited multifidus study.
That study used a symmetrical biphasic waveform, 50 pulses per second, and a 400 µs pulse duration. The Select Combo II provides a symmetrical biphasic rectangular waveform, NMES pulse widths from 200–400 µs, adjustable pulse rate, and TENS/NMES amplitude up to 100 mA.
It also has a low-back body-area group and customizable U1 programming.
View InTENSity Select Combo II DI2195
Its adjustable NMES specifications provide the closest overall handheld feature alignment with parameters used in published surface-NMES multifidus research.
For operation and custom programming, see our Select Combo II setup and troubleshooting guide.
Chattanooga Intelect NMES Digital: The Dedicated Clinical Alternative
The current specifications list two isolated channels, 0–80 mA output per channel at a 500-ohm load, 2–120 Hz adjustable pulse frequency, and 50–300 µs adjustable pulse width. It also provides adjustable contraction/rest timing.
View Chattanooga Intelect NMES Digital 77717
Its main disadvantage relative to the multifidus research question is that its pulse width tops out at 300 µs rather than 400 µs.
That does not prevent it from activating lumbar muscles. It simply means the Select Combo II offers somewhat greater parameter overlap with that particular published study.
Balego EMS Digital: The Simpler Dedicated NMES Choice
For users who do not require TENS, interferential, or Russian stimulation, the Balego EMS Digital offers a simpler, dedicated muscle-stimulation approach.
It provides two isolated channels and adjustable pulse rate, pulse width, ramp time, contraction time, relaxation time, and treatment duration.
View Balego EMS Digital NMES Stimulator
Its role in this article should be positioned around value and dedicated NMES functionality, not a claim that it is inherently better at reaching the multifidus.
What About a Four-Channel Device?
The Richmar Twin Stim Plus DS5402 becomes particularly appealing when a physical therapy clinic wants a larger or more flexible bilateral electrode arrangement.
It provides four isolated output channels, accommodates as many as eight electrodes, and includes EMS/NMES, TENS, interferential, and Russian modes. Its EMS rate is adjustable from 2 to 150 Hz with pulse widths from 50 to 300 µs.
View Richmar Twin Stim Plus DS5402
More electrodes or channels should not be interpreted as automatically producing deeper stimulation. The value is placement flexibility and bilateral coverage.
Is Russian Stimulation Better for Reaching Deep Multifidus?
This is a claim I would specifically avoid.
Russian current can certainly produce strong muscular contractions, and some manufacturers describe medium-frequency stimulation as more comfortable at higher output. But it is too simplistic to state that Russian stimulation “penetrates deeper” and therefore must activate the multifidus better.
Depth and quality of recruitment are influenced by current density, waveform, electrode spacing, nerve location, tissue impedance, anatomy, and amplitude.
A strong or comfortable sensation is not proof that the desired deep muscle has been selectively recruited.
The better clinical endpoint is the following:
Can the practitioner verify an appropriate contraction of the intended musculature?
That might be determined through palpation, movement assessment, or rehabilitative ultrasound imaging.
Should NMES Be Combined With Multifidus Exercises?
Probably the most evidence-aligned way to present NMES is as an adjunct to active rehabilitation.
The 2021 Scientific Reports study examined NMES alongside motor-control exercise and found improved lumbar multifidus activation with the combined intervention compared with motor-control exercise accompanied by sham NMES.
A 2025 randomized study similarly found that both stabilization-exercise groups improved, while multifidus thickness increased more prominently when NMES was added.
That provides a stronger editorial position than promising that someone can place pads on their back and passively “strengthen their core.”
A physical therapist might use NMES to make the contraction easier to identify and then integrate that recruitment into controlled movement, stabilization exercise, or functional retraining.
For general parameter education, read our clinical NMES settings guide
Surface NMES vs. an Implanted “Multifidus Stimulator”
These are entirely different technologies.
| Surface NMES | Implanted Multifidus Neurostimulation | |
|---|---|---|
| Stimulation delivery | Electrodes on skin | Surgically implanted leads |
| Targeting | Motor nerves/tissue beneath an electrode field | Specific neural target associated with multifidus activation |
| Typical setting | PT, rehab or clinician-guided home program | Specialist evaluation and implantation |
| Procedure required | No | Yes |
| Equivalent technologies? | No | No |
That evidence does not claim that a portable surface NMES unit produces the same treatment or outcomes.
“multifidus stimulator” vs. “NMES for multifidus.”
Frequently Asked Questions
Can a TENS unit strengthen the multifidus?
Conventional TENS is primarily intended to create sensory stimulation rather than a purposeful strengthening contraction. If the objective is muscle activation or neuromuscular re-education, NMES/EMS is the more relevant modality.
Can electrical stimulation reach the deep multifidus?
Research using rehabilitative ultrasound has demonstrated activation and increased thickness of both superficial and deep lumbar multifidus during transcutaneous NMES. Surface stimulation cannot guarantee selective activation of the deep multifidus in every individual.
Where are NMES electrodes placed for the multifidus?
Published research has placed electrodes over the lumbar paraspinal region rather than directly on the spinal midline. A frequently cited study used four 2 × 2-inch electrodes positioned around L2 and S1 bilaterally.
That should be described as a research configuration rather than a universal self-treatment placement.
What pulse width has been used for multifidus NMES?
A 2019 study used a 400 µs pulse duration at 50 pulses per second with symmetrical biphasic stimulation. Other research has used different waveforms and frequencies, so no single combination should be presented as universally optimal.
Which Balego stimulator is the best match for multifidus activation?
For clinician-directed portable use, I would rank the InTENSity Select Combo II DI2195 first because its NMES capabilities include a 400 µs pulse-width option, adjustable frequency, up to 100 mA output in TENS/NMES modes, and custom programming.
The Chattanooga Intelect NMES Digital 77717 would be my preferred dedicated NMES alternative.
Does higher intensity always produce better multifidus activation?
Not necessarily. The 2019 study found greater multifidus thickening among participants who tolerated higher amplitudes, but contraction quality, comfort, fatigue, electrode placement, and unwanted recruitment all matter. Increasing stimulation until it becomes painful is not an appropriate treatment objective.
Is ReActiv8 the same as a surface multifidus stimulator?
No, ReActiv8 is an implanted restorative neurostimulation system with an FDA-approved indication for a defined chronic-low-back-pain population. Portable NMES units stimulate through electrodes on the skin and should not be presented as equivalent.
Bottom Line
Surface NMES can activate the lumbar multifidus. Ultrasound research demonstrates measurable multifidus contraction during transcutaneous lumbar stimulation, including changes involving deeper multifidus tissue.
The limitation is selectivity.
A handheld surface stimulator may recruit the multifidus along with neighboring lumbar paraspinals, and no portable unit should be marketed as guaranteeing isolation of the deepest fibers.
For a clinician whose specific objective is multifidus recruitment, look for an NMES-capable device with adequate output, adjustable pulse parameters, and suitable electrode-placement flexibility rather than a basic TENS-only unit.
Within the portable lineup, we position the InTENSity Select Combo II DI2195 as the best overall feature match, followed by the Chattanooga Intelect NMES Digital 77717 as the dedicated clinical NMES choice.
