Biofeedback és ETS a rehabilitációban – mit tud és mit nem?
In this article I describe two main clinical applications of biofeedback: post-stroke rehabilitation and urinary incontinence. Electrical therapies were introduced in the electric therapy methods article; related topics are detailed in the NMES in rehabilitation and practical management of incontinence articles.
Key idea
Biofeedback and ETS are not standalone cures – they are part of a comprehensive rehabilitation program. For post-stroke shoulder-hand syndrome, a recent systematic review [1] found that EMG-biofeedback combined with physiotherapy is the most effective physical treatment for reducing pain and improving function. In upper-limb stroke rehab the latest review [2] indicates that biofeedback alone is not always superior to conventional rehabilitation. For urinary incontinence, EMG-biofeedback did not provide significant additional benefit over standard pelvic-floor exercises [4][5], whereas pressure-based biofeedback [6] produced significant symptom improvement—especially in postpartum women. Device selection and parameter settings are indication-specific and require specialist or physiotherapist consultation.
Main types of biofeedback
In clinical practice three main types of biofeedback are used, each with different applications:
EMG-biofeedback measures the electrical activity produced during muscle contraction using surface electrodes. The user receives visual or auditory feedback about muscle activity and can learn to activate or relax a specific muscle intentionally. ETS (EMG-Triggered Stimulation) goes one step further: when the patient’s voluntary attempt reaches a minimal threshold of muscle activity, the device automatically delivers electrical stimulation that completes or amplifies the contraction. This is crucial for weak post-stroke muscles [1][3]—the patient “relearns” to link intention with muscle movement.
Pressure biofeedback uses a probe inserted into the vagina or rectum to measure pressure generated by the muscles and displays the level of muscle activity visually in real time. It is particularly useful for pelvic floor muscle training, where patients often cannot perceive muscle activity otherwise. A recent clinical trial [6] found that pressure biofeedback combined with pelvic floor muscle training produced significantly better recovery rates than exercises alone for postpartum stress incontinence. Note: EMG-biofeedback did not show a meaningful advantage for this indication [4][5]—the clinical value of the two biofeedback types may differ in incontinence.
Other members of the biofeedback family include heart rate variability (HRV) biofeedback (autonomic balance, stress management), EEG-biofeedback (neurofeedback) (modulation of brain activity patterns; investigated in ADHD, anxiety), temperature biofeedback (Raynaud's syndrome, peripheral circulation), and breathing biofeedback (relaxation, adjunctive asthma therapy). These modalities are typically most effective when applied by a multidisciplinary team (physiotherapist, psychologist, neurologist); home devices are available but limited.
In which conditions is biofeedback used?
Current clinical evidence supports measurable benefit in the following areas. In all cases it is used as a complementary modality within a multidisciplinary package:
A large, multi-center systematic review [1] reported that EMG-biofeedback combined with physiotherapy is the most effective physical treatment for post-stroke shoulder-hand syndrome—improving both upper-limb motor function (range of motion, muscle strength) and pain reduction, outperforming other physical methods. Another clinical trial [3] in chronic stroke patients showed significant improvement in upper-limb recovery using a triple combination of functional electrical stimulation + mirror therapy + EMG-triggered biofeedback. Important: stroke rehabilitation is the responsibility of a multidisciplinary team (neurologist, physiotherapist, occupational therapist).
Evidence is nuanced: a large UK trial [4] found that EMG-biofeedback plus pelvic-floor exercises was NOT meaningfully better than exercises alone for stress or mixed urinary incontinence. The full professional report [5] confirmed this. However, a more recent trial [6] reported that in postpartum women the pressure biofeedback combined with pelvic-floor training achieved significantly better recovery rates. Clinical takeaway: biofeedback type (EMG vs pressure) and the treated population (general vs postpartum) can affect effectiveness. Responsible device selection is necessary. Details: incontinence treatment in practice.
A systematic review [2] reported mixed results for surface EMG-guided rehabilitation interventions in improving upper-limb function—most studies showed measurable improvement from baseline, but biofeedback was not clearly superior to conventional rehabilitation. Lesson: biofeedback is a promising motor-learning tool, but on its own, without physiotherapy, it does not add benefit. Larger trials are needed to clarify uncertain areas.
Biofeedback (EMG, HRV, temperature) is a classic application for chronic headache, temporomandibular disorder (TMD), muscular tension and stress-related complaints. The method is typically effective as part of a psychotherapeutic package (cognitive behavioral therapy, relaxation techniques). Alone, without supervision by a physiotherapist or clinical psychologist, home use has limited effectiveness; combined with professional-led sessions it is more effective.
In sports rehab EMG-biofeedback primarily supports the motor-learning process—for example, after injury an athlete learns to selectively activate a muscle group or avoid compensatory movement patterns. Evidence here is more limited (sport-specific, fewer trials), but practical usefulness in a clinical setting with physiotherapist guidance is accepted. Alone, without supervised practice, it is less effective.
SineBravo vs. DuoBravo N – key differences
Medimarket's portfolio includes several types of biofeedback devices. SineBravo provides feedback only, while other devices such as DuoBravo, PeroBravo, evostim E and evostim P also offer active stimulation (ETS). These DO NOT substitute for one another—they have different functions and clinical goals:
| Feature | SineBravo | DuoBravo N |
|---|---|---|
| Primary function | FEEDBACK ONLY | stimulator + ETS (EMG-Triggered Stimulation) |
| Electrical stimulation? | ✗ NO | ✓ yes |
| ETS function? | ✗ NONE | ✓ yes (triggered by patient’s voluntary attempt) |
| Main indication | visualizing own muscle activity, pelvic-floor awareness, motor learning | central paresis (stroke), active rehabilitation |
| What does the patient learn? | targeted muscle activation / relaxation | linking intention + automatic stimulated completion |
| Number of channels | 2 | 2 |
| Home use | ✓ yes (simpler) | ✓ yes, but professional supervision recommended |
The two devices are NOT interchangeable
SineBravo is aimed at those who want to visualize and learn their own muscle activity (e.g., to improve pelvic-floor awareness). DuoBravo N is a key tool for active stroke rehabilitation: when the device detects the patient’s weak voluntary attempt it automatically triggers muscle stimulation to complete or amplify the movement. This supports brain "neuroplastic" relearning—restoring the link between intention and movement.
Medimarket biofeedback and ETS devices
The following biofeedback and related devices are available in the Medimarket portfolio:
- SineBravo – a FEEDBACK ONLY device (NO stimulation), for visualizing own muscle activity and improving pelvic-floor awareness.
- DuoBravo N – muscle stimulator with ETS (EMG-Triggered Stimulation) function, specifically for active post-stroke rehabilitation.
- PeroBravo – selective stimulation device for peripheral paresis (denervated muscle).
- evostim E - an EMG-based biofeedback device specialized for incontinence treatment with ETS function
- evostim P - a pressure-based biofeedback device specialized for incontinence treatment with ETS function
Incontinence-specific probe biofeedback devices are available in the incontinence category page.
Typical biofeedback / ETS protocol parameters
Protocols used in recent clinical trials vary; factory programs of home devices are optimized. The table below is for guidance:
| Parameter | Range | Note |
|---|---|---|
| Muscle-activity threshold (ETS) | 5–20% | individual setting; lower for weaker patients |
| Stimulation parameters (ETS) | 30–50 Hz, 200–400 µs | standard for muscle stimulation, depends on muscle type |
| Session duration | 20–30 minutes/session | stroke rehab: 30 min; incontinence: 20 min |
| Frequency | 3–5 sessions/week | most clinical trials used 3–5× per week |
| Program period | 4–16 weeks | stroke rehab: 4 weeks; incontinence protocol: 12–24 weeks |
| Supervision | initially physiotherapist-led | home continuation only after training |
| Type of feedback | visual (bar, curve), auditory cues | patient-specific, motivational |
When is biofeedback / ETS NOT recommended?
Pure biofeedback devices (sensor + visual feedback) carry minimal risk. For ETS and stimulation devices the general electrotherapy contraindications apply (see: electrical treatment contraindications and electrical treatment and implants):
- Pacemaker, ICD, implanted neurostimulator – only with cardiologist/arrhythmologist approval (for stimulation devices).
- Pregnancy – avoid abdominal and lumbar regions.
- Active malignant tumor in the treatment area.
- Active venous thrombosis (DVT) in the treatment area.
- Fresh skin wound, eczema, infection at the electrode site.
- Poorly controlled epilepsy – individual specialist evaluation (for stimulation devices).
- Metal implant in the stimulation area – risk of electrical heating.
- Carotid sinus, anterior neck region, placement over the chest above the heart – to be avoided.
- Acute vaginal / rectal inflammation for probe biofeedback.
- Fresh vaginal tissue injury or within 6 weeks postpartum – gynecologist approval required.
For new, worsening or unexplained symptoms always seek medical/physiotherapist consultation before starting biofeedback on your own.
Frequently asked questions about biofeedback and ETS
SineBravo is FEEDBACK ONLY—it measures with sensors and visually reports muscle activity but does NOT provide electrical stimulation. DuoBravo N is a combined device: a muscle stimulator with ETS (EMG-Triggered Stimulation). ETS means that when the patient’s voluntary attempt reaches a threshold of muscle activity, the device automatically stimulates the muscle to complete or amplify the movement. In post-stroke rehabilitation DuoBravo N is a key tool; for general biofeedback training (e.g., pelvic-floor awareness) SineBravo is sufficient.
Most clinical trials examined regular use over 4–16 weeks. Changes can be measurable within 4 weeks in stroke rehabilitation; pelvic-floor training programs typically run 12–24 weeks. Results vary by individual. Patience and consistency are key—meaningful change is not expected after just one or two sessions.
No, it does not replace it. Recent clinical studies [1][2][4] all show that biofeedback is most effective when combined with conventional rehabilitation (physiotherapy, exercise therapy, manual therapy). Alone, without physiotherapy, it does not add benefit—but used alongside (e.g., ETS in stroke) it can provide clinical improvement.
The evidence is mixed. A large UK trial [4] found that EMG-biofeedback did not add benefit over pelvic-floor exercises alone for stress and mixed urinary incontinence. A more recent clinical trial [6], however, showed a significant advantage for pressure biofeedback in postpartum women. The two biofeedback types measure different mechanisms, and patient population (general vs postpartum) may affect outcomes. Consult a gynecologist / urogynecologist / pelvic-floor specialist physiotherapist before choosing a device.
Yes, especially in the initial phase. Clinical trials typically use a physiotherapist-led introduction, followed by home continuation. In stroke rehab correct electrode placement, muscle-activity threshold settings and stimulation parameters require physiotherapist expertise. For incontinence protocols a pelvic-floor specialist teaches correct muscle activation first. Home use is appropriate only after learning the correct technique.
Pure biofeedback devices (like SineBravo), which only measure and do not stimulate electrically, generally do not cause interference with a pacemaker—but cardiology approval is advisable before use. Devices that also provide stimulation (DuoBravo N ETS, evoStim) should not be used with a pacemaker without cardiologist/arrhythmologist clearance. Details are in the electrical treatment and implants article.
Summary – biofeedback and ETS in brief
What every interested person should know
- Biofeedback is real-time biological feedback (muscle activity, pressure, heart rate, brain waves, etc.) that helps learn self-regulation.
- ETS (EMG-Triggered Stimulation) automatically initiates stimulation based on the patient's voluntary attempt—key in stroke rehabilitation.
- Strong evidence: post-stroke shoulder-hand syndrome—the EMG-biofeedback + physiotherapy combination proved the most effective physical treatment [1].
- Mixed evidence: stress and mixed urinary incontinence—EMG-biofeedback adds no benefit [4][5], but pressure biofeedback gives significant improvement in postpartum women [6].
- Products: SineBravo (FEEDBACK ONLY, NO stimulation), DuoBravo N (stimulator + ETS, key for stroke), MyoBravo (EMS biofeedback), PeroBravo (selective, denervated).
- Biofeedback / ETS is a complementary modality—it does not replace conventional rehabilitation, physiotherapy or specialist care.
- Physiotherapist-led introduction is essential; home device use only after training.
- Contraindications (pacemaker, pregnancy, tumor, fresh skin wound, acute fever) must be strictly observed.
Scientific sources (2020+)
References [1]–[6] cited in the article refer to the following studies (number = list order):
-
Feng S, Tang M, Huang G, Wang J, He S, Liu D, Gu L.
EMG biofeedback combined with rehabilitation training may be the best physical therapy for improving upper limb motor function and relieving pain in patients with the post-stroke shoulder-hand syndrome: A Bayesian network meta-analysis.
Frontiers in Neurology.
2023;13:1056156.
PMID: 36703623.
Brief summary: Bayesian network meta-analysis of 45 randomized controlled trials (total 3,379 post-stroke patients); the EMG-biofeedback + rehabilitation combination had a SUCRA of 96.8%, making it the most effective physical treatment. -
Munoz-Novoa M, Kristoffersen MB, Sunnerhagen KS, Naber A, Alt Murphy M, Ortiz-Catalan M.
Upper Limb Stroke Rehabilitation Using Surface Electromyography: A Systematic Review and Meta-Analysis.
Frontiers in Human Neuroscience.
2022;16:897870.
PMID: 35669202.
Brief summary: Systematic review and meta-analysis of 24 randomized trials (808 stroke patients); sEMG-guided interventions did not show a clear advantage over conventional rehabilitation for improving upper-limb function. -
Kim YS, Song JY, Park SH, Lee MM.
Effect of functional electrical stimulation-based mirror therapy using gesture recognition biofeedback on upper extremity function in patients with chronic stroke: A randomized controlled trial.
Medicine (Baltimore).
2023;102(52):e36546.
PMID: 38206692.
Brief summary: Randomized trial of 26 chronic stroke patients; combination of functional electrical stimulation + mirror therapy + EMG-biofeedback significantly improved upper-limb motor function after 4 weeks. -
Hagen S, Elders A, Stratton S, Sergenson N, Bugge C, Dean S, et al.
Effectiveness of pelvic floor muscle training with and without electromyographic biofeedback for urinary incontinence in women: multicentre randomised controlled trial.
BMJ.
2020;371:m3719.
PMID: 33055247.
Brief summary: Multicentre UK randomized trial of 600 women with stress/mixed urinary incontinence; EMG-biofeedback + pelvic-floor training was NOT meaningfully better (ICIQ-UI SF 8.2 vs 8.5; p=0.84) than exercises alone at 24 months follow-up. -
Hagen S, Bugge C, Dean SG, Elders A, Hay-Smith J, et al.
Basic versus biofeedback-mediated intensive pelvic floor muscle training for women with urinary incontinence: the OPAL RCT.
Health Technology Assessment.
2020;24(70):1-144.
PMID: 33289476.
Brief summary: The OPAL trial HTA report confirms the BMJ publication: EMG-biofeedback does not add meaningful benefit to pelvic-floor exercises and is not cost-effective. -
Wang X, Qiu J, Li D, Wang Z, Yang Y, Fan G, et al.
Pressure-Mediated Biofeedback With Pelvic Floor Muscle Training for Urinary Incontinence: A Randomized Clinical Trial.
JAMA Network Open.
2024;7(11):e2442925.
PMID: 39499517.
Brief summary: Multicenter randomized trial of 452 postpartum women with stress urinary incontinence; pressure biofeedback + pelvic-floor training showed significantly better recovery rates (20.2% vs 8.7%; p=0.001) than exercises alone at 3 months.
This article is for general informational purposes and does not replace personal medical consultation. Biofeedback and ETS devices are CE-marked medical devices; cited clinical trials were conducted with different devices and protocols, and individual results may vary. The method is a complementary modality and does not replace conventional rehabilitation, prescribed medications or specialist diagnosis. Before acquiring devices for stroke, incontinence or other rehabilitation, consult a specialist or physiotherapist to choose the appropriate device. Contraindications (pacemaker, pregnancy, tumor, fresh skin wound) must be strictly observed.
