Unit 3: Electrical Stimulation Parameters and Applications
⚡ NMES (Neuromuscular Electrical Stimulation)
Purpose / Why:
Used to strengthen muscles, prevent atrophy, reduce spasticity or edema, and improve ROM in patients with intact peripheral nerves. Common after orthopedic or neurological injury (e.g., ACL reconstruction, stroke, TKA).
Target Tissue:
Innervated skeletal muscle (stimulates motor nerves to activate muscle fibers)
Type of Current:
Pulsed biphasic current (symmetrical or asymmetrical)
NMES Typical Parameters
Parameter Typical Range / Description
Frequency 30–80 Hz (pps) → 50 Hz ideal for tetanic contraction
Pulse Duration 200–350 µs (up to 400 µs for larger muscles)
Ramp 1–2 seconds for comfort (up to 3 sec for spastic muscles)
On:Off Ratio 1:3 to 1:5 (e.g., 10s ON / 30–50s OFF)
Intensity To produce a strong, visible tetanic contraction (≥50% MVC)
Total Treatment Time 10–20 contractions or about 10–20 minutes (3–5x per week)
Why To re-educate muscle, strengthen post-surgery, improve recruitment, and reduce disuse atrophy
⚙ Russian Stimulation (BMAC – Burst Modulated Alternating Current)
Purpose / Why:
Used primarily for muscle strengthening through strong tetanic contractions. It’s a form of NMES with medium frequency designed for comfort and deeper activation.
Target Tissue:
Innervated skeletal muscle (via motor nerve stimulation)
Type of Current:
Burst Modulated Alternating Current (BMAC)
Carrier frequency: 2,500 Hz
Burst frequency: 50 Hz
Russian Typical Parameters
Parameter Typical Range / Description
Frequency Carrier = 2,500 Hz; Burst = 50 bursts/sec
Pulse Duration Determined by burst width (typically ~400 µs per cycle)
Ramp 2 seconds up and down (comfortable transition)
On:Off Ratio 10s ON / 50s OFF (≈20% duty cycle, 1:5 ratio)
Intensity As high as tolerated to produce strong tetanic contraction (~50–70% MVC)
Total Treatment Time ~10–20 minutes or until fatigue (10–20 contractions)
Why To build strength, prevent atrophy, and retrain muscle activation in orthopedic rehab (e.g., quadriceps post-ACL or TKA)
🦾 FES (Functional Electrical Stimulation)
Purpose / Why:
FES uses NMES during functional activities (movement-based tasks) to restore or assist voluntary motor control.
Common in neurological conditions — e.g., stroke, CP, SCI — to improve gait, hand grasp/release, and shoulder subluxation.
Target Tissue:
Innervated skeletal muscle (stimulates motor nerves for functional contraction)
Type of Current:
Pulsed biphasic current (symmetrical or asymmetrical, low to medium frequency)
Typical FES Electrode Placements
Upper Extremity (e.g., Stroke – Shoulder Subluxation or Hand Function)
Shoulder Subluxation:
One electrode on posterior deltoid
One on supraspinatus
Goal: elevate humeral head into glenoid fossa (avoid abduction)
Hand Function (Grasp/Release):
Electrodes placed over wrist and finger extensors/flexors
Adjusted to produce functional hand opening or closing
Gait / Lower Extremity (Foot Drop Correction)
Dorsiflexion Assist:
One electrode on tibialis anterior
One on peroneal nerve region near fibular head
Goal: activate dorsiflexors during swing phase of gait
Often used with FES cuff system triggered by a heel sensor
FES Typical Parameters
Parameter Typical Range / Description
Frequency 30–40 Hz (smooth contraction)
Pulse Duration 200–350 µs
Ramp 0–1 sec for gait, 2–3 sec for UE comfort
On:Off Ratio Timed with task (manual trigger or gait sensor)
Intensity Sufficient to achieve functional movement (3–5/5 contraction)
Total Treatment Time 20–45 minutes, task-dependent
Why To restore function, improve motor learning, and enhance neuroplasticity through activity-specific repetition
✅ Summary Table
Parameter NMES Russian FES
Current Type Biphasic pulsed Burst-modulated AC Biphasic pulsed
Frequency 30–80 Hz 2,500 Hz carrier / 50 Hz burst 30–40 Hz
Pulse Duration 200–350 µs ~400 µs (burst width) 200–350 µs
Ramp 1–2 sec 2 sec 0–3 sec
On:Off Ratio 1:3 to 1:5 1:5 (10 on / 50 off) Timed with task
Intensity ≥50% MVC ≥50–70% MVC Functional movement level
Treatment Time 10–20 min 10–20 min 20–45 min
Primary Goal Strengthening / re-education Strengthening / hypertrophy Functional movement (gait, grasp, posture)
Target Tissue Innervated skeletal muscle Innervated skeletal muscle Innervated skeletal muscle
Electrode Placement Over motor points Over motor points Over task-specific muscles (UE: deltoid/supraspinatus, LE: tibialis anterior)