Unit 3: Electrical Stimulation Parameters and Applications

What is the purpose of NMES (Neuromuscular Electrical Stimulation)?

Used to strengthen muscles, prevent atrophy, reduce spasticity or edema, and improve ROM in patients with intact peripheral nerves.

What type of current is used in NMES?

Pulsed biphasic current (symmetrical or asymmetrical).

What are the typical frequency parameters for NMES?

30–80 Hz, with 50 Hz being ideal for tetanic contraction.

What is the ideal pulse duration for NMES for larger muscles?

Up to 400 µs.

What is the recommended ramp time for NMES?

1–2 seconds for comfort, up to 3 seconds for spastic muscles.

What is the typical On:Off ratio for NMES?

1:3 to 1:5 ratio (e.g., 10s ON / 30–50s OFF).

What is the target tissue for NMES?

Innervated skeletal muscle.

What is the total treatment time for NMES sessions?

10–20 contractions or about 10–20 minutes, 3–5 times per week.

What is the purpose of Russian Stimulation (BMAC)?

Used primarily for muscle strengthening through strong tetanic contractions.

What is the type of current used in Russian Stimulation?

Burst Modulated Alternating Current (BMAC).

What are the typical parameters for frequency in Russian Stimulation?

Carrier = 2,500 Hz; Burst = 50 bursts/sec.

What is the typical pulse duration for Russian Stimulation?

Typically ~400 µs per cycle based on burst width.

What is the ramp time for Russian Stimulation?

2 seconds up and down for comfortable transition.

What is the typical On:Off ratio for Russian Stimulation?

10s ON / 50s OFF (approximately 20% duty cycle, 1:5 ratio).

What intensity level is used in Russian Stimulation?

As high as tolerated to produce strong tetanic contraction (approximately 50–70% MVC).

What is the total treatment time for Russian Stimulation?

About 10–20 minutes or until fatigue, typically involving 10–20 contractions.

What is the primary goal of Functional Electrical Stimulation (FES)?

To restore or assist voluntary motor control during functional activities.

What are the common conditions FES is used for?

Common in neurological conditions such as stroke, CP, and SCI.

What type of current is used in FES?

Pulsed biphasic current (symmetrical or asymmetrical, low to medium frequency).

What is the typical frequency for FES?

30–40 Hz for smooth contraction.

What is the typical pulse duration used in FES?

200–350 µs.

What is the ramp time for FES for gait?

0–1 second for gait, 2–3 seconds for upper extremity comfort.

What is the On:Off ratio for FES?

Timed with the task (manual trigger or gait sensor).

What is the intensity required for FES to achieve functional movement?

Sufficient to achieve a contraction level of 3–5/5.

What is the total treatment time for FES?

20–45 minutes, dependent on the task.

In NMES, what is the goal of treatment?

To re-educate muscle, strengthen post-surgery, improve recruitment, and reduce disuse atrophy.

What is a common use of NMES after an injury?

Common after orthopedic or neurological injuries such as ACL reconstruction or stroke.

What is unique about the burst frequency in Russian Stimulation?

It utilizes a carrier frequency of 2,500 Hz and a burst frequency of 50 Hz.

How is electrode placement determined for FES?

Over task-specific muscles (e.g., deltoid/supraspinatus for upper extremity, tibialis anterior for lower extremity).

What is the recovery goal for FES in patients after stroke regarding shoulder subluxation?

To elevate the humeral head into the glenoid fossa.

How does NMES help with muscle atrophy prevention?

By providing electrical stimulation that engages muscle fibers and promotes contraction.

What is the typical intensity level in NMES to achieve a strong, visible contraction?

Greater than or equal to 50% of maximum voluntary contraction (MVC).

What is the ramp adjustment for patients with spastic muscles in NMES?

Up to 3 seconds for comfort.

What are two primary treatment parameters that differ between NMES and FES?

Total treatment time and On:Off ratio.

Which stimulation method is designed for deeper activation with comfort?

Russian Stimulation (BMAC).

What significant aspect of muscle recruitment can NMES improve?

Muscle recruitment after disuse or surgery.

How is FES typically applied during rehabilitation?

During functional tasks to restore motor function.

What is the goal of the ramp time in electrical stimulation therapies?

To provide a comfortable transition in muscle contraction.

What does the ratio of 1:5 in FMES indicate?

10 seconds ON and 50 seconds OFF frequency setting.

What electrical current type is utilized during NMES treatment?

Biphasic pulsed current.

What is the importance of using a short ramp in FES for gait assistance?

To allow for quick and effective muscle activation during ambulation.

How does the application of FES affect neuroplasticity?

By enhancing neuroplasticity through activity-specific repetition.

What is the minimum frequency setting in NMES for effective results?

30 Hz.

What is the ideal intensity range for Russian stimulation?

50–70% of maximum voluntary contraction (MVC).

What treatment parameter is adjusted to produce functional hand opening or closing in FES?

Electrode placement on wrist and finger extensors/flexors.

How often should NMES treatments be administered per week for optimal outcome?

3–5 times per week.

What is the maximum pulse duration used in NMES for larger muscle groups?

Up to 400 µs.

What type of contraction does NMES aim to achieve?

Tetanic contraction.

What primary benefit does Russian Stimulation provide in rehabilitation?

Muscle strengthening and hypertrophy.

In FES, what is the electrode placement for dorsiflexion assist?

One on tibialis anterior and one on the peroneal nerve region near the fibular head.

What electrical muscle stimulation technique is often used for gait improvement in stroke patients?

Functional Electrical Stimulation (FES).

What does BMAC stand for?

Burst Modulated Alternating Current.

What frequency is typically applied in FES during muscle stimulation?

30–40 Hz.

What is a common goal for using NMES post-surgery?

Strengthening and re-educating the muscle.

What type of current is typically avoided in NMES applications?

Constant direct current.

What is the purpose of the On:Off ratio in NMES therapy?

To ensure intervals of activation and rest for muscle recovery.

In NMES, what is the significance of achieving ≥50% MVC?

To ensure a strong, visible contraction during treatment.

What is the role of electrodes in FES for hand function?

To control grasp and release by stimulating wrist and finger muscles.

How can FES assist patients with shoulder subluxation due to stroke?

By positioning electrodes on musculature to stabilize the shoulder.

For what reason is ramp time adjusted in NMES for spastic muscles?

To enhance comfort during muscle contractions.

What is a significant effect of repeated FES use on muscle imbalances?

Improved muscle activation patterns and reduced imbalances.

What is typically the upper limit of treatment time for NMES?

20 minutes.

What does the FES technique aid in promoting for patients post-stroke?

Motor learning and functional recovery.

What is a common muscle targeted for FES to enhance gait improvement?

Tibialis anterior.

What does the 'burst' in Russian Stimulation refer to?

Groupings of pulses delivered at a specific frequency within a cycle.

In electrical stimulation parameters, what does the abbreviation 'MVC' stand for?

Maximum Voluntary Contraction.

Why is 50 Hz an optimal frequency for NMES?

It achieves ideal conditions for causing tetanic contractions.

What is the primary difference in treatment focus between NMES and FES?

NMES focuses on strength and re-education; FES focuses on functional movement.

For FES during task-specific activities, what is a critical component of electrode placement?

Placement over motor points related to the specific task.

What significant parameters are essential for effective NMES settings?

Frequency, pulse duration, ramp time, On:Off ratio, intensity, and total time.

Which method is frequently recommended for retraining muscle activation in orthopedic rehab?

Russian Stimulation.

How does NMES contribute to rehabilitation post-surgery?

Strengthening and muscle re-education to facilitate recovery.

What is typically adjusted in FES to account for individual functional needs?

The intensity and electrode placement based on task-specific functions.

In which case might a therapist opt to use Russian stimulation over typical NMES?

When higher intensity and stronger contractions are required for deeper muscle activation.

What is a notable characteristic of the pulsed biphasic current used in NMES?

It effectively stimulates motor nerves to activate muscle fibers.

What is one key advantage of the ramp feature in electrical stimulation treatments?

It helps prevent muscle soreness and discomfort during activation.

What treatment duration is recommended for FES sessions based on task performance?

20–45 minutes, adjusted according to the specific task.

What is the rationale for a 1:5 On:Off ratio in NMES therapy?

To emphasize recovery time while enabling effective muscle contraction.

When using FES for foot drop correction, which muscle is primarily targeted?

Tibialis anterior.

What type of rehabilitation settings most commonly utilize NMES?

Orthopedic and neurological rehabilitation settings.

What should the intensity of electrical stimulation in FES achieve?

It should be sufficient to induce functional movements.