What is TES (Threshold Electrical Stimulation), and what is it for?
A number of childhood neurological disorders cause so-called central (brain-origin) paralysis — the most characteristic form being cerebral palsy (CP). In the affected muscles the lost brain-to-muscle connection and the absence of contractions eventually lead to muscle atrophy (loss of muscle), and this is one of the major causes of long-term disability. Karen Pape developed the TES method — Threshold Electrical Stimulation — to prevent this.
TES IS NOT the same as TENS!
The acronyms look similar, but the two methods are fundamentally different:
- TENS = Transcutaneous Electrical Nerve Stimulation — for pain relief.
- TES = Threshold Electrical Stimulation — sub-contraction muscle activation for cerebral palsy.
Do not confuse them! This article discusses only the Pape-style Threshold ES.
Key idea
According to the Pape protocol, TES uses electrical stimulation below the sensory threshold: it does not produce a visible muscle contraction, but it increases blood flow and nutrient delivery to the muscle. The goal: to prevent disuse-related muscle atrophy over a long period (6× per week, 8–12 hours per night, 2–4 years). The scientific evidence is mixed — some studies are positive, others negative. Modern NMES evidence is stronger in CP, but TES remains part of the multimodal approach.
Why is continuous “pulsation” important for muscle?
All muscles connect to the spinal cord and brain via motor nerves. In a healthy body this connection is continuously active and functions in both directions. This regulates, among other things, muscle tone: about 10% of muscle fibers are always in a contracted state, and fibers "take turns". This provides constant postural support.
Without the fine, continuous pulsation of muscle fibers, the regulation of circulation would fail — during sleep muscle tone plays a key role in vascular control. Part of the return of peripheral blood to the heart is driven by the muscle pump.
When the connection between muscle and nerve is interrupted:
- If the interruption is in the spinal cord or brain (central paralysis, e.g. CP, stroke): muscles that lose connection gradually stiffen — they become spastic.
- If the nerve injury is peripheral, after the spinal cord (denervated muscle, e.g. peroneal palsy): the muscles become completely flaccid.
In both cases it is only a matter of time before muscle tissue deteriorates. In the absence of contractions degenerative processes begin: the cytoplasm of wasted fibers (the cellular material necessary for function) decreases, actin and myosin (the contractile elements of muscle fibers) are reduced or absent, and ultimately muscle cells are replaced by connective tissue and fat. This process typically completes over one and a half to two years — after which the paralysis can become permanent.9
NMES vs FES vs TES — what is the difference?
The term “electrical stimulation” covers a whole group of therapeutic methods. In cerebral palsy you will encounter three characteristic forms, each with a different aim:
NMES (Neuromuscular Electrical Stimulation)
The classic “muscle stimulation.” It delivers strong pulses that produce visible muscle contractions. The child may rest or actively cooperate, but the stimulator can also work independently. Aim: increase muscle strength, neuromuscular retraining.
A 2023 meta-analysis (14 RCTs, 421 children with spastic CP) found that NMES measurably improved walking speed and global motor function (GMFM) compared with conventional physiotherapy.5 A 2022 meta-analysis (8 RCTs, 294 children with CP) showed that NMES combined with task-oriented/constraint-induced therapy improved hand function and upper-limb strength.7
ETS (Electromyography Triggered Stimulation)
ETS is an advanced form of NMES: the stimulation is triggered by a voluntarily performed functional movement. Its most typical use is post-stroke motor relearning and correction of foot-drop (peroneal palsy) — the stimulation activates the peroneal-innervated muscles during the swing phase of gait.8
So ETS is “movement-activated” stimulation, while NMES is “static, seated or supine” stimulation. Both evoke muscle contraction — TES does NOT.
TES (Threshold Electrical Stimulation)
Threshold electrical stimulation uses sub-contraction stimulation — the pulse intensity is below the sensory threshold. It does not produce visible muscle contraction and is generally not consciously felt by the child. Its effect works through increased blood flow and cellular nutrient delivery.
This method is specifically intended to keep the muscle alive rather than to strengthen it. It complements the other two methods, it does not replace them.
How does TES work? — The blood flow theory
The mechanism of TES is not fully clarified, but the most accepted theory is the following:
- Sub-contraction current is applied to the muscle (below sensory threshold, approx. 1–2 mA range).
- The current locally increases blood flow in the muscle tissue — like a mild "massage."
- The increased blood flow delivers growth factors and nutrients to the muscle fibers.
- These growth factors and nutrients are particularly pushed into the bloodstream during sleep — hence TES is used with a nocturnal protocol.
- Well-nourished muscle fibers "repair themselves" and regenerate. Under the microscope after TES treatment an increased amount of cytoplasm is seen and regrowth of actin/myosin is observed.
The regrowth of wasted fibers takes about 3–6 months — so TES is not immediate but a long-term maintenance therapy. Muscle growth requires continuous therapy: according to the Pape protocol, six nights per week, 8–12 hours per night, for 2–4 years.
Important context
TES does not replace other treatments (physiotherapy, orthoses, NMES, surgery) but complements them. It can be part of a complex CP therapy — not a standalone solution. The appropriate therapy team (pediatric neurologist, pediatric physiotherapist) should help determine TES indications and fitting.
What do studies say about TES?
It is important to discuss the scientific background: the evidence is mixed. Some studies show positive results, others negative. Modern NMES evidence is stronger for general muscle problems in CP — TES specifically targets "keeping muscles alive" as a preventive application.
“Where did TES originate? — Pape's first demonstration”
The method is associated with the work of Karen Pape (Toronto). In a 1993 proof-of-concept study on 6 mildly affected children with CP, 6 months of nightly subthreshold ES produced measurable improvements on the Peabody motor development scales — the gains disappeared after stopping treatment and returned when treatment was resumed.1 This formed the basis of the TES protocol.
“What did the largest TES trial show?”
The most rigorous double-blind, placebo-controlled trial (Dali et al., 2002) followed 57 ambulant children with CP (ages 5–18) for 12 months comparing active TES vs placebo. The result: NO significant difference in motor function, range of motion, spasticity, or CT-measured muscle growth.2 This means: TES alone — in this carefully designed trial — did not produce clearly better results than placebo.
“Were there positive TES results?”
Yes, in specific populations. A 1997 clinical trial (Steinbok et al.) in children who had undergone selective dorsal rhizotomy (SDR — a surgical procedure for drug-resistant spasticity) showed that active TES produced significantly better GMFM results (5.5% vs 1.9%, p=0.001) at one-year follow-up.3 Thus, in a surgically modified subgroup TES showed a validated effect.
“What does modern NMES deliver in CP? (for comparison)”
Modern NMES evidence is stronger: a 2023 meta-analysis (14 RCTs, 421 children with spastic CP) showed measurable improvements in walking speed and global motor function with NMES.5 A 2021 pediatric meta-analysis (18 studies, 595 children with CP, spinal muscular atrophy or brachial plexus injury) found NMES improved muscle strength, movement biomechanics and functional mobility.6
“What does a Cochrane-level review say?”
The 2004 systematic review by Kerr and colleagues (analyzing TES, NMES and FES studies in CP) concluded that the evidence for strength and function improvement is "promising but limited" due to small sample sizes and methodological weaknesses.4
How to interpret this?
TES is a specific, targeted method — not a universal miracle. Results are mixed, so it is not recommended as the sole main treatment for CP. Modern NMES has a stronger evidence base for improving strength and function, while TES can play a complementary role — especially for long nocturnal application to prevent muscle atrophy. Always choose the method after medical consultation.
Devices suitable for the TES protocol
Nightly (8–12 hours), sub-contraction TES requires a device that can operate programmably at low intensity for long durations. Currently available 4-channel multifunction electrotherapy devices meet this purpose:
Globus Genesy 300 Pro
Multifunction electrotherapy device with TENS, EMS, NMES, FES, MENS, MCR and iontophoresis programs. 4-channel (8 electrodes). Program parameters can be finely tuned for the TES protocol. Suitable for home use.
Globus Premium 400
Multifunction Globus device. TENS, EMS, NMES, MCR and iontophoresis programs. 4-channel, compact design. Usable for the TES protocol — parameter fine-tuning according to the user manual.
Globus Genesy 600 / Genesy 1500
Versatile high-end Globus models with hundreds of programs. Individual parameter settings are possible, so the Pape-style TES protocol can be configured. For complex rehabilitation needs.
My advice on settings
The TES protocol for children should always be determined by a pediatric physiotherapist or pediatric neurologist. Sensory threshold varies between children — fine-tuning is a specialist task. Parents or caregivers can be trained to use the home device.
The classic Pape TES protocol
Below is the "original" TES protocol recorded by Pape. In real application it must be adjusted to the child's age, muscular status and coordination with other treatments under the guidance of a pediatric neurologist/physiotherapist:
| Parameter | Value | Note |
|---|---|---|
| Intensity | ~1–2 mA | Below sensory threshold, DOES NOT produce visible contraction |
| Frequency | ~35 Hz | Continuous, low |
| Duration (one night) | 8–12 hours | During sleep, uninterrupted |
| Per week | 6 nights | One night off per week |
| Total duration | 2–4 years | Long-term, maintenance therapy |
| Electrode placement | Target muscles | Usually calf, thigh, as indicated by the physiotherapist |
TES is a pediatric treatment
TES is recommended specifically for children diagnosed by a neurologist. Home use should always be started with a physiotherapy specialist — knowledge of electrode placement, intensity setting and safety rules is essential. Supervision during the first weeks of nightly treatment is the responsibility of the parent or caregiver.
Before you start TES treatment
TES is contraindicated or requires specialist consultation in the following situations:
- Missing pediatric / pediatric neurology diagnosis — TES is indicated only in properly diagnosed CP or similar childhood neurological conditions.
- Implanted pacemaker, ICD or other active implant — electrical treatment is forbidden nearby.
- Acute fever or infectious illness — wait for recovery.
- Skin disease, injury or sensory loss at the treatment site — skin should be intact.
- Active malignant tumor in the treatment area — avoid the affected region.
- Epilepsy or other seizure disorders — stimulation may trigger seizures; specialist approval required.
- Severe cardiovascular disease — in arrhythmia or heart failure seek cardiology clearance.
- Too young age — typically under 2 years the use of TES should be considered individually by the pediatrician.
- Severe intellectual or communication difficulties — if the child cannot report discomfort, application requires closer supervision.
- Unsupervised nightly application — initially always under parent/caregiver supervision with secure electrode fixation.
Further reading
For the full contraindication list and technology-specific information read our article on electrical treatment contraindications.
Frequently Asked Questions
Fundamentally. TENS (Transcutaneous Electrical Nerve Stimulation) is a pain-relief method — it stimulates sensory nerve fibers to block signal flow to the brain. TES (Threshold Electrical Stimulation) works below the sensory threshold to nourish muscle tissue. TENS is short (20–30 minutes), TES is long (8–12 hours nightly). Different device, different goal, different protocol.
According to the Pape protocol, yes — preventing muscle atrophy requires continuous therapy. In modern practice the duration is individualized based on the child's condition and relation to other therapies. The neurologist and physiotherapist regularly reassess treatment.
The method is specific and does not produce equally measurable results in every child. The largest double-blind trial (Dali 2002) did not show a significant difference from placebo in the overall sample2 — another (Steinbok 1997) showed a positive effect in a post-rhizotomy subpopulation.3 So: not guaranteed, but may be useful in certain situations. Do not use it alone — use it as part of a comprehensive treatment program under pediatric neurologist guidance.
The following approach should be specialist-led: NMES for strengthening (visible contraction), ETS for functional motor relearning (gait, arm movements), TES to "keep the muscle alive" (preventive, nocturnal sub-contraction). Modern CP protocols often use them together alongside physiotherapy.5, 7
It was originally developed by Pape for that purpose. The principle (nocturnal sub-contraction, blood-flow-enhancing stimulation to counteract muscle atrophy) could theoretically be applied to other childhood neurological conditions (e.g. spinal muscular atrophy, brachial plexus injury), but targeted clinical evidence is lacking. 6 Traditional NMES has been studied in several pediatric conditions beyond CP.
Most pediatric NMES/TES studies have found the method safe — complications are rare and acceptability is good.3, 6 The most important factors are specialist supervision at initiation, correct electrode placement, and parental supervision (especially during the first nights). If skin problems appear, treatment is stopped.
Summary — Quick overview
Sources
- Pape KE, Kirsch SE, Galil A, Boulton JE, et al. (1993). Therapeutic electrical stimulation (TES) for the treatment of disuse muscle atrophy in cerebral palsy. Journal of Pediatric Orthopedics 13(5):628-633. PubMed: 8376565
- Dali C, Hansen FJ, Pedersen SA, Skov L, et al. (2002). Threshold Electrical Stimulation (TES) in ambulant children with CP: a randomized double-blind placebo-controlled clinical trial. Developmental Medicine & Child Neurology 44(6):364-369. PubMed: 12088304
- Steinbok P, Reiner A, Kestle JR. (1997). Therapeutic electrical stimulation following selective posterior rhizotomy in children with spastic diplegic cerebral palsy: a randomized clinical trial. Developmental Medicine & Child Neurology 39(8):515-520. PubMed: 9295846
- Kerr C, McDowell B, McDonough S. (2004). Electrical stimulation in cerebral palsy: a review of effects on strength and motor function. Developmental Medicine & Child Neurology 46(3):205-213. PubMed: 14995090
- Chen YH, Wang HY, Liao CD, Liou TH, Escorpizo R, Chen HC. (2023). Effectiveness of neuromuscular electrical stimulation in improving mobility in children with cerebral palsy: a systematic review and meta-analysis of randomized controlled trials. Clinical Rehabilitation 37(1):3-16. PubMed: 35730135
- Cobo-Vicente F, San Juan AF, Larumbe-Zabala E, et al. (2021). Neuromuscular Electrical Stimulation Improves Muscle Strength, Biomechanics of Movement, and Functional Mobility in Children With Chronic Neurological Disorders: A Systematic Review and Meta-Analysis. Physical Therapy 101(10):pzab170. PubMed: 34184031
- Ou CH, Shiue CC, Kuan YC, Liou TH, Chen HC, Kuo TJ. (2023). Effectiveness of Neuromuscular Electrical Stimulation for Upper-Limb Function and Reducing Spasticity in Children With Cerebral Palsy: A Meta-Analysis. American Journal of Physical Medicine & Rehabilitation 102(2):151-158. PubMed: 35687763
- Khamis S, Herman T, Krimus S, Danino B. (2018). Is functional electrical stimulation an alternative to ankle-foot orthotic management in children with cerebral palsy?. European Journal of Paediatric Neurology 22(1):7-16. PubMed: 29102346
- Leandro de Albuquerque G, da Silva Souza V, Matheus Santos da Silva Calado C, et al. (2024). Effects of perinatal anoxia and sensorimotor restriction on skeletal muscle and microglia in animal models of cerebral palsy: a systematic review and meta-analysis. Neuroscience 563:93-109. PubMed: 39515512
