Spasticity can interfere with walking, reaching, grasping, dressing, positioning, hygiene, exercise, and other daily activities. It commonly develops after damage to the brain or spinal cord and is associated with conditions such as stroke, spinal cord injury, traumatic brain injury, cerebral palsy, and multiple sclerosis.
Clinically, true spasticity is distinguished by a greater reflex response when a muscle is stretched quickly than when it is stretched slowly. Not every stiff or difficult-to-move limb is spastic; joint contracture, pain, weakness, dystonia, swelling, and soft-tissue shortening can create different movement problems that require different treatment. (PubMed)
Neuromuscular electrical stimulation, or NMES, may be included in a clinician-directed rehabilitation plan to activate a selected muscle and create a controlled contraction. One possible strategy is to stimulate the antagonist, meaning the muscle that performs the movement opposite the spastic muscle.
The Balego EMS Digital NMES Stimulator is a portable, dual-channel muscle stimulator with adjustable pulse rate, pulse width, ramp, contraction time, rest time, treatment timer, and intensity. Its constant, synchronous, and alternate modes support different contraction-based rehabilitation workflows.
Clinical-use notice: Spasticity is associated with a neurological condition and should be evaluated by a qualified medical or rehabilitation professional. The settings in this article are educational reference values, not individualized treatment instructions.
What is reciprocal inhibition?
Muscles frequently work in opposing pairs. When one muscle contracts to create a movement, the nervous system normally reduces activity in the muscle that performs the opposite movement. This neurological coordination is known as reciprocal inhibition.
For example:
- the ankle dorsiflexors oppose the ankle plantarflexors;
- the wrist extensors oppose the wrist flexors;
- the finger extensors oppose the finger flexors;
- the triceps oppose the elbow flexors;
- Hip abductors oppose the hip adductors.
In an antagonist-stimulation program, NMES is applied to the muscle opposing the spastic pattern. The intended sequence is:
- Electrical pulses activate the antagonist muscle’s motor nerve.
- The antagonist produces a controlled contraction.
- Spinal inhibitory pathways may reduce activity in the opposing spastic muscle.
- The temporary change may make stretching, voluntary movement, positioning, or functional training easier.
- Rehabilitation begins while the person has an improved opportunity to practice the desired movement.
Neurophysiological research involving the tibialis anterior and soleus has shown that peripheral electrical stimulation can influence spinal inhibitory reflex pathways, although the response depends on stimulation frequency, diagnosis, and individual neurological status. (PubMed)
Is NMES proven to reduce spasticity?
Electrical stimulation of antagonist muscles has been investigated in people with stroke and spinal cord injury, but it should not be described as a guaranteed or permanent treatment.
A randomized, assessor-blinded stroke study evaluated tibialis anterior NMES as an addition to conventional rehabilitation. Other clinical research has specifically examined stimulation of the tibialis anterior for plantarflexor spasticity, ankle dorsiflexion, strength, gait, and lower-extremity motor recovery. (PubMed)
A double-blind crossover study also compared functional electrical stimulation and TENS for lower-limb spasticity in people with spinal cord injury. More recent randomized research continues to investigate surface and intramuscular stimulation of the tibialis anterior in stroke survivors. These studies use different devices, doses, diagnoses, outcome measures, and stimulation methods, so their settings should not be combined into one universal protocol. (PubMed)
The most supportable conclusion is as follows:
NMES may temporarily influence muscle tone, antagonist activation, range of motion, or movement performance in selected patients, but results vary. It is generally most useful as an adjunct to active rehabilitation rather than as a stand-alone intervention.
Reciprocal-inhibition NMES versus other stimulation approaches
| Approach | Where stimulation is applied | Primary objective | Expected response |
|---|---|---|---|
| Antagonist NMES | Muscle opposing the spastic muscle | Encourage antagonist contraction and reciprocal inhibition | Visible movement away from the spastic pattern |
| Direct agonist NMES | Spastic or weak target muscle | Used for selected strengthening, motor-control, or fatigue-based strategies | Contraction of the directly stimulated muscle |
| Functional electrical stimulation | Muscle timed with a task such as stepping or grasping | Assist or retrain a functional movement | Contraction coordinated with activity |
| Sensory-level TENS | Nerve or treatment region without a strong motor contraction | Sensory input or temporary pain modulation | Tingling without a substantial contraction |
| NMES plus task training | Antagonist or functional muscle followed by active practice | Convert a temporary physiological effect into useful movement | Contraction followed by active participation |
The appropriate strategy depends on the neurological diagnosis, movement goal, voluntary control, sensation, joint mobility, fatigue, and whether the spasticity is helping or interfering with function.
NMES settings for spasticity reduction
These values come from the historical protocol and should not be interpreted as settings for every patient.
| Parameter | Legacy setting | What the setting controls |
|---|---|---|
| Target | Antagonist of the spastic muscle | Muscle intended to move opposite the spastic pattern |
| Pulse rate | 20 Hz | Twenty electrical pulses per second |
| Pulse width | 300 μs | Duration of each individual pulse |
| Up-ramp | 4 seconds | Gradual rise toward the selected intensity |
| On-time | 6 seconds | Contraction interval shown in the original preset |
| Down-ramp | 1.5 seconds | Gradual decrease in stimulation |
| Off-time | 50 seconds | Long recovery interval between contractions |
| Channels | Single or dual | One or two pairs of electrodes |
| Channel coordination | Simultaneous | Both channels contract together |
| Legacy waveform | Symmetrical biphasic | Alternating, charge-balanced waveform |
| Intensity | Increased according to tolerance | Intended to produce a substantial antagonist contraction |
| Legacy schedule | Three to six sessions daily | Frequency listed in the historical document |
| Legacy treatment course | Five to ten treatment days | Course listed in the original protocol |
| Rehabilitation timing | Immediately after stimulation | Intended to use the temporary period of reduced tone |
Why did the protocol use 20 Hz?
The historical program describes 20 Hz as a relatively low pulse rate chosen to produce an antagonist contraction while limiting fatigue. At lower motor-stimulation frequencies, individual contractions begin to merge into a smoother contraction while generally placing less demand on the muscle than a substantially higher rate.
That does not mean 20 Hz is automatically appropriate for every patient. Contraction quality depends on:
- neurological diagnosis;
- amount of voluntary control;
- motor-point placement;
- pulse width;
- intensity;
- electrode size;
- muscle size;
- fatigue;
- medications;
- joint position and biomechanical resistance.
Why is the rest interval 50 seconds?
The six-second contraction is followed by a 50-second recovery period—an approximate work-to-rest ratio of 1:8 when only the stated on-time is considered.
The long rest period appears to be intended to:
- limit fatigue in a neurologically impaired antagonist;
- preserve contraction quality;
- avoid reinforcing abnormal co-contraction;
- allow the limb to return to its starting position;
- Prepare for another controlled movement.
A shorter rest period may cause the contraction to weaken progressively. A longer rest interval may be appropriate when the muscle fatigues rapidly, but the complete program must be set by the treating clinician.
Increase intensity gradually until the intended antagonist muscle produces a strong, visible, controlled, and tolerable contraction. The movement should occur in the desired direction without sharp pain, burning, excessive joint stress, or uncontrolled compensation.
Program settings to the Balego NMES
The Balego EMS Digital NMES Stimulator can reproduce several numerical values from the legacy protocol, but it cannot duplicate the entire waveform and timing sequence exactly.
| Legacy setting | Balego NMES capability | Translation issue |
|---|---|---|
| 20 Hz pulse rate | Adjustable from 2–150 Hz | A 20 Hz rate can be selected |
| 300 μs pulse width | Adjustable from 50–300 μs | A 300 μs width can be selected |
| Simultaneous channels | Synchronous mode | Both channels activate together |
| Four-second up-ramp | Ramp adjustable from 1–8 seconds | A four-second ramp can be selected |
| Separate 1.5-second down-ramp | One ramp setting in whole seconds | The exact separate down-ramp cannot be entered |
| Six-second on-time | On-time adjustable from 2–90 seconds | Balego on-time includes ramp-up and ramp-down |
| 50-second rest | Off-time adjustable from 0–90 seconds | A 50-second rest can be selected |
| Symmetrical biphasic waveform | Asymmetrical rectangular biphasic waveform | The output waveform is different |
| One or two channels | Dual isolated channels | Either one or both channels may be used |
| Historical daily schedule | The timer is adjustable from 1 to 60 minutes or continuous | Timer capability does not validate the legacy dose |
The current Balego manual states that synchronous-mode on-time includes both the rising and falling ramp periods. Consequently, an on-time of six seconds combined with a four-second ramp would leave a small or negligible plateau, depending on how the device distributes the ramp. A clinician translating the concept should choose timing based on the desired total contraction cycle rather than copying “6 seconds” without adjustment.
The Balego device provides a 1–8 second ramp, 2–90 second on-time, 0–90 second off-time, 2–150 Hz rate, and 50–300 μs pulse width. It uses an asymmetrical rectangular biphasic pulse and provides independent intensity control for two isolated channels.
Educational Balego programming framework
This framework explains how a clinician might translate the concept. It is not an individual prescription.
| Balego control | Clinician-directed consideration |
|---|---|
| Mode | Synchronous when both channels should activate together |
| Rate | The legacy reference used 20 Hz |
| Pulse width | The legacy reference used 300 μs |
| Ramp | Select a gradual rise and fall that creates a controlled movement |
| On-time | Must be long enough to contain both ramps and the intended contraction |
| Off-time | Long enough to preserve contraction quality and limit fatigue |
| Intensity | Strong, visible, controlled, and tolerable antagonist contraction |
| Timer | Based on response, fatigue, skin condition, and the rehabilitation goal |
| Channel use | One channel for a small muscle group; two when broader recruitment is clinically necessary |
Review the complete Balego NMES instruction manual before programming the device. The manual explains that placement and settings should be clinician-directed and that on-time must accommodate the ramp intervals.
Electrode placement for reciprocal-inhibition NMES
The central placement principle in the legacy protocol is
Place the electrodes over the antagonist of the spastic muscle—not automatically over the muscle that feels tight.
The original protocol allows either one or two channels. It recommends two electrodes for a smaller antagonist muscle group and up to four electrodes for a larger muscle group or when one channel does not create a satisfactory response. It also notes that motor points may be harder to locate in patients with spasticity, making placement adjustments necessary.
Examples of antagonist selection
| Common spastic pattern | Muscle group that may be selected for antagonist stimulation | Intended movement |
|---|---|---|
| Ankle plantarflexion or equinovarus tendency | Tibialis anterior and other dorsiflexors, as clinically appropriate | Ankle dorsiflexion |
| Wrist flexion | Wrist extensors | Wrist extension |
| Finger flexion | Finger extensors | Opening the hand |
| Elbow flexion | Triceps | Elbow extension |
| Hip adduction | Hip abductors | Moving the leg away from midline |
| Knee flexion | Knee extensors | Knee extension |
These relationships do not establish where pads should be placed on a specific person. A therapist must identify the actual spastic pattern, available range, motor points, joint stability, voluntary control, and treatment goal.
Step-by-step placement workflow
1. Identify the movement problem
Determine whether the limiting problem is true spasticity, fixed contracture, weakness, pain, poor selective control, dystonia, swelling, or a combination.
2. Identify the spastic muscle and its functional antagonist
The treatment target should be based on the movement that needs to improve—not simply the location of perceived tightness.
3. Position the limb safely
Support the limb so that the induced movement cannot cause a fall, overstretch a joint, pull against a contracture, or interfere with a healing structure.
4. Inspect sensation and skin
Do not apply electrodes over broken, irritated, infected, inflamed, or substantially numb skin. Check that the patient can communicate abnormal discomfort.
5. Prepare the skin
Clean and dry the area. Remove lotion, oil, perspiration, and other substances that may interfere with adhesion. Clip excessive hair rather than shaving immediately before stimulation.
6. Place one electrode near an antagonist motor point
The first electrode is generally positioned where a clear response can be obtained at the lowest practical intensity.
7. Place the second electrode along the same muscle group
Position the second pad to complete the electrical path through the intended muscle while avoiding prohibited anatomical locations.
8. Add a second channel only when needed
A second electrode pair may provide broader recruitment of a large antagonist group. Both channels may be operated together in synchronous mode when simultaneous contraction is intended.
9. Begin with both intensity controls at zero
Increase output gradually while observing the movement.
10. Adjust placement before simply increasing intensity
When the wrong muscle contracts—or no useful movement occurs—repositioning the electrodes may be more effective than continuing to increase output. The Balego manual specifically notes that electrode placement is a major factor in NMES success and may require experimentation by the clinician.
What should a successful response look like?
A useful antagonist contraction should be
- visible and directed toward the desired movement;
- smooth rather than abrupt;
- repeatable after each rest period;
- strong enough to move or activate the intended segment;
- free of sharp pain, burning, or excessive pulling;
- produced without substantial unwanted movement elsewhere;
- followed by relaxation during the off-time.
Stop or reassess when stimulation produces worsening spasticity, marked clonus, pain, autonomic symptoms, unusual weakness, loss of balance, or an unsafe joint position.
Choosing electrode size
The original protocol refers to approximately 1¾-inch square pads for smaller muscles and approximately 1¾-by-3¾-inch pads for larger muscle groups. Current Balego reusable TENS, NMES, and FES electrodes are available in five sizes.
| Balego electrode | Relative coverage | Potential role in an NMES setup |
|---|---|---|
| 1.25-inch round | Smallest | Compact muscles or tight placement areas when clinically appropriate |
| 2-inch round | Small to medium | Curved or smaller muscle regions |
| 2-inch square | Medium | General-purpose antagonist muscle placement |
| 2-by-3.5-inch rectangle | Medium to large | Larger muscle groups or broader current distribution |
| 2.75-inch round | Large | Broad curved areas |
The electrodes are made in the United States from American-made raw materials and include a 0.040-inch reusable hydrogel layer, conductive carbon film, flexible spun-lace backing, and soft-molded connector.
A smaller electrode concentrates current over a smaller area and may feel stronger at the same device setting. Return intensity to zero whenever electrode size or placement is changed.
What should happen immediately after stimulation?
The historical protocol states that the reduction in spasticity may be temporary and recommends beginning the rehabilitation activity immediately after NMES.
This is one of the most clinically important parts of the document. Stimulation should create an opportunity for activity—not simply a brief change in tone.
Depending on the individual plan, the post-stimulation period may include:
| Functional goal | Possible follow-up activity |
|---|---|
| Reduce ankle plantarflexor interference | Dorsiflexion practice, standing alignment, stepping, or gait training |
| Improve hand opening | Reaching, grasp-and-release, hygiene, splint application, or object manipulation |
| Improve elbow extension | Supported reaching, weight-bearing, or active extension |
| Reduce hip-adductor interference | Positioning, transfers, standing, stepping, or hygiene-related movement |
| Improve passive range | Slow clinician-directed stretching followed by active control |
| Improve selective movement | Repeated task practice emphasizing the newly available movement |
Electrical stimulation combined with conventional or task-based rehabilitation has been studied for post-stroke ankle and upper-extremity recovery, reinforcing that the stimulated contraction is usually best connected to a meaningful movement goal. (PubMed)
Appropriate treatment frequency depends on the following:
- neurological diagnosis;
- chronicity and severity of spasticity;
- stimulated muscle;
- treatment intensity;
- contraction and recovery times;
- skin tolerance;
- fatigue;
- medication timing;
- associated rehabilitation;
- functional response;
- availability of professional monitoring.
Session duration and frequency should be prescribed individually. Do not adopt the legacy three-to-six-times-daily schedule unless it has been reviewed for the current patient, device, diagnosis, and rehabilitation plan.
NMES safety and contraindications
Powered muscle stimulation should be used under medical supervision as adjunctive therapy for medical conditions. FDA labeling guidance lists muscle-spasm relaxation, muscle re-education, local circulation support, prevention or retardation of disuse atrophy, and maintaining or increasing range of motion among recognized powered-muscle-stimulator indications. (U.S. Food and Drug Administration)
Do not apply NMES:
- over the carotid sinus region;
- over the front or side of the neck;
- over the mouth or throat;
- across the chest;
- through the head;
- over broken, irritated, infected, or inflamed skin;
- over or near cancerous lesions;
- in a configuration prohibited by the device manual;
- while driving, operating machinery, or performing an activity in which an involuntary contraction could cause injury.
The Balego manual contraindicates use in patients with cardiac demand pacemakers and warns that skin irritation and burns beneath electrodes can occur. (balego.com)
Do not use on patients with any of the following conditions:
- implanted electronic devices;
- suspected cardiac disease or arrhythmia;
- pregnancy;
- substantially impaired sensation;
- recent surgery;
- recent fracture or unstable joint;
- severe contracture;
- suspected blood clot or vascular inflammation;
- active infection;
- cancer;
- uncontrolled seizures;
- unexplained changes in neurological status.
FDA guidance also advises caution following surgery when muscle contraction could disrupt healing, over skin lacking normal sensation, and during pregnancy. It states that electrode placement and settings should follow the prescribing practitioner’s guidance. (U.S. Food and Drug Administration)
Balego device comparison for spasticity-related rehabilitation
No portable stimulator should be selected solely because it contains an “NMES” mode. The clinician must also consider manual setting control, number of channels, battery type, need for TENS or other modalities, and whether the device can create the intended work-rest pattern.
| Product | Modalities | Channels | Programming strengths | Best fit |
|---|---|---|---|---|
| Balego EMS Digital NMES Stimulator | Dedicated NMES/EMS | 2 | Adjustable rate, width, ramp, on-time, off-time, timer; Constant, Synchronous, and Alternate modes | Focused, clinician-programmed muscle activation and re-education |
| Twin Stim IV | TENS and NMES | 2 | Preset body-region programs, custom NMES program, rechargeable battery, treatment tracking | One portable unit for both sensory TENS and contraction-based NMES |
| InTENSity Select Combo II | TENS, NMES, IFC, and Russian | 2 | Multiple modalities, presets, custom configurations, rechargeable design | Clinics or users requiring broader electrotherapy options |
| Balego Four Channel Stim | TENS, EMS/NMES, IFC, and Russian | 4 | Four independent channels and broad multi-region coverage | Larger or more complex clinician-directed electrode configurations |
The Balego EMS Digital is the closest fit when the main need is manual control of contraction and recovery intervals. The Twin Stim IV is more suitable when both TENS and NMES are required in a rechargeable device. The Select Combo II and four-channel model provide additional modality and coverage options.
Browse the complete Balego Neuromuscular Stimulation collection for dedicated NMES units, combination devices, lead wires, electrodes, and clinical electrotherapy systems.
Frequently asked questions
Can NMES reduce spasticity?
NMES may temporarily influence spasticity or muscle tone in selected patients, especially when it activates the antagonist of a spastic muscle. Results vary by diagnosis, placement, settings, and rehabilitation program. It should not be presented as a cure or permanent solution.
What settings did the original spasticity protocol use?
The original protocol used:
- 20 Hz pulse rate;
- 300 μs pulse width;
- four-second up-ramp;
- six-second on-time;
- 1.5-second down-ramp;
- 50-second off-time;
- simultaneous single- or dual-channel stimulation.
These are historical reference values, not universal treatment settings.
Can the Balego NMES duplicate this protocol?
It can reproduce 20 Hz, 300 μs, a four-second ramp, and a 50-second off-time. It cannot reproduce the separate 1.5-second down-ramp or the legacy symmetrical biphasic waveform. Its on-time also includes the ramp periods, so the six-second legacy value should not be copied without clinician adjustment. (balego.com)
Are electrodes placed over the spastic muscle?
This protocol does not include the reciprocal-inhibition strategy. The electrodes are placed over the muscle that opposes the spastic muscle. Other NMES strategies may use different targets, so placement must follow the clinician’s treatment objective.
How strong should the contraction be?
The antagonist should produce a clear, controlled, and tolerable contraction in the desired direction. Stimulation should not be increased simply to reach the device’s highest intensity or create the strongest possible movement.
Why is the rest time so long?
The historical program used a 50-second recovery after a six-second contraction. The long rest interval was intended to reduce antagonist fatigue and maintain contraction quality.
Should exercise follow NMES?
Yes, when clinically appropriate. The historical document specifically recommends beginning rehabilitation immediately because any reduction in spasticity may be temporary.
Is TENS the same as NMES for spasticity?
No. TENS generally creates sensory stimulation without a substantial contraction. NMES activates motor nerves and produces a visible contraction. Some research has examined both approaches, but they use different physiological strategies and should not be treated as interchangeable. (PubMed)
Can NMES be used after a stroke?
NMES and FES have been studied in post-stroke rehabilitation, including stimulation of wrist extensors and ankle dorsiflexors. The patient’s medical stability, sensation, cognition, joint condition, tone pattern, and rehabilitation goals must be evaluated before treatment. (PubMed)
Can this protocol be used at home?
Only after a qualified practitioner has identified the correct antagonist muscle, demonstrated electrode placement, programmed the device, and established safety and stopping criteria. Spasticity-related home programs require more guidance than general muscle-conditioning use.
Conclusion
The legacy NM III Program F illustrates a clinically recognizable approach to NMES for spasticity reduction through reciprocal inhibition: stimulate the antagonist muscle at a relatively low pulse rate, allow a long recovery interval, and immediately use the temporary change during active rehabilitation.
Its core concept remains educationally useful, but the original device settings, waveform, “maximum contraction” wording, and intensive daily schedule should not be transferred uncritically to a modern home program.
For current equipment, the Balego EMS Digital NMES Stimulator provides adjustable pulse rate, pulse width, ramp, on-time, off-time, and dual-channel synchronous operation. Review the Balego NMES instruction manual, select compatible Balego reusable NMES electrodes, and have a qualified clinician determine the muscle target, placement, intensity, schedule, and functional follow-up activity.
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