Unit 3 DP 1

What does NMES stand for?

Neuromuscular Electrical Stimulation

What is the primary purpose of NMES?

To induce skeletal muscle contraction.

List one indication for using NMES.

Muscle strengthening.

What type of contraction does NMES aim to prevent?

Disuse atrophy.

Which physiological system does NMES bypass to recruit muscle fibers?

The central nervous system (CNS).

What is the recruitment order during voluntary contraction?

Small (slow-twitch) to large (fast-twitch) muscle fibers.

In NMES-induced contraction, is the recruitment selective or non-selective?

Non-selective.

What is the effect of NMES on muscle fatigue compared to voluntary contraction?

Faster fatigue due to synchronous firing.

What type of current is Russian current classified as?

Burst-Modulated Alternating Current (BMAC).

What is the carrier frequency of Russian current?

2500 Hz.

What duty cycle is typically used with Russian current?

10 sec ON / 50 sec OFF.

What does NMES using pulsed current typically target?

Smaller muscles or when precise control is needed.

At what frequency do muscles start to exhibit smooth contractions?

30 Hz.

What frequency range leads to ideal tetanic contractions?

50 Hz.

What frequency is considered to have a risk of fatigue?

100 Hz.

What are the long-term effects of NMES on muscle mass?

Increase in muscle fiber cross-sectional area.

What neurological effects occur in the short-term from NMES?

Increase in recruited motor units and firing frequency.

What is the minimum intensity recommended for NMES strengthening?

≥50% of maximum voluntary contraction (MVC).

What is the typical pulse duration range for NMES?

200–350 µs.

How many contractions should be targeted per NMES session?

10–20 contractions.

What is a common NMES session frequency?

3–5 times per week.

What ramp up time is preferred to transition in NMES settings?

~2 seconds.

What is the risk of using a high frequency greater than 100 Hz in NMES?

Faster fatigue and not ideal for strengthening.

What is the goal of adjusting the placement of electrodes on the tibialis anterior?

To achieve a balanced dorsiflexion.

What parameter influences the off-time in NMES to avoid fatigue?

Longer rest (off-time).

What muscle recruitment evidence was found with MRI studies for NMES?

Activated deep muscle fibers even with superficial electrodes.

What is the term used for stimulation in denervated muscle?

Electrical Stimulation (ES).

What is the pulse duration required for denervated muscle stimulation?

≥10 ms.

Which regions should electrodes not be placed over?

Trunk/heart, pelvic region, carotid bodies.

What potential risk exists from prolonged DC exposure during electrical stimulation?

Skin burns.

What is a common precaution when using NMES in patients with cognitive impairment?

Use with caution.

For which medical device should electrodes not be placed over the heart?

Pacemaker or ICD.

What placement is recommended for achieving effective stimulation of the posterior rotator cuff?

Aim to move the humeral head superiorly in the glenoid.

What parameter ranges are recommended for NMES frequency?

30–50 Hz.

What is a typical parameter for NMES ramp down time?

~2 seconds.

In NMES for muscle strengthening, what intensity should the amplitude reach?

50–70% MVC of the contralateral limb.

What is one of the primary benefits of NMES in rehabilitation?

Improves muscle strength even with neuromuscular deficits.

What duration of NMES treatment is typically recommended?

10–20 contractions per session.

How does NMES impact muscle recruitment pattern compared to voluntary contractions?

NMES produces synchronous recruitment.

What is a common characteristic of fatigue in NMES?

Faster fatigue due to synchronous firing.

How does the pulse duration for innervated muscle compare to that of denervated muscle?

Innervated muscle has a pulse duration of 0.2 ms, while denervated muscle requires ~10 ms.

What is a potential concern when using NMES near diathermy units?

Electromagnetic interference.

What should be avoided in patients with arrhythmias when using electrical stimulation?

Caution should be used due to cardiac dysfunction.

What is the response of muscles at frequencies less than 10 Hz?

Unfused twitches.

What is the effect of NMES on deep muscle activation based on MVC levels reported?

Notable activation at 25% MVC and widespread activation at 50–75% MVC.

What is a common frequency setting for NMES to yield smooth tetany?

30–50 Hz.

What factors influence NMES treatment parameters according to individual patient tolerance?

Higher amplitudes and longer durations yield stronger contractions.

What is an example of a duty cycle used in Russian current?

10 seconds ON / 50 seconds OFF.

What effect does a longer off-time have on fatigue during NMES?

It reduces fatigue.

Which parameter should be considered for muscle contraction comfort during NMES?

Ramp time of ~1–2 seconds is preferred.

What clinical benefit does NMES provide in muscle recruitment despite CNS control?

It can recruit deep muscle fibers for strength improvement.

What is the typical frequency range for pulsed current in NMES?

1–1000 Hz.

How can NMES contribute to rehabilitation therapy for patients with neuromuscular deficits?

By improving muscle strength through deep fiber activation.

What type of stimulation should be used with caution over areas near neoplasms?

NMES or ES.

What is a preventative measure for using NMES in patients with compromised skin?

Avoid using electrodes directly on affected skin.

Where should electrodes NOT be placed to avoid interfering with critical bodily functions?

Over the phrenic nerve or bladder stimulator.

What is the desired outcome of NMES for muscle atrophy prevention?

To induce muscle contractions to maintain muscle integrity.

What is important to monitor during NMES sessions to ensure patient safety?

Skin integrity and sensation.

What is an appropriate NMES setting for a patient with communication difficulties?

Careful monitoring and adjustments based on observed responses.

How does the recruitment of motor units differ between voluntary and NMES-induced contractions?

Voluntary is CNS-driven, while NMES is externally driven by electrodes.

What is the maximum tolerable intensity you can set for NMES?

It should be at least 50% of maximum voluntary contraction.

What is the role of duty cycle in NMES applications?

To balance contraction and relaxation phases.

What is a good example of a NMES placement tip for large muscle groups?

Large pads with multiple electrodes may improve effectiveness.

What do prolonged periods of NMES stimulation risk in patients?

Skin burns or irritation.

What is the significance of using longer pulse durations in ES for denervated muscles?

To effectively depolarize the muscle fibers without nerve input.

What parameter combination could enhance the effectiveness of NMES for rehabilitation?

Combining varied pulse duration and intensity levels.

Which muscle group is often targeted for NMES in cases of foot drop?

Peroneals.

What optimal pulse duration for NMES is recommended before exceeding comfortable limits?

Up to 400 µs.

What benefit does NMES provide for patients unable to perform voluntary movements?

It encourages muscle contraction and rehabilitation.

What kind of adaptation is observed early on with NMES intervention?

Neural adaptation.

When is NMES frequency set to produce unfused twitches optimally?

Below 10 Hz.

What is the clinical relevance of achieving tetanic plateau at 50 Hz?

It allows for maximal strength gain without excessive fatigue.

What modification may be necessary for electrode placement in very large patients?

Using more than two electrodes for larger surface area coverage.

What specific characteristic of NMES serves as an advantage over voluntary contractions?

Synchronous recruitment of multiple muscle fibers.

What effect does NMES have on muscle fibers after prolonged use?

Increased muscle fiber cross-sectional area leading to hypertrophy.

What might patients feel during NMES treatment?

A strong muscle contraction sensation.

What is the recommended outlier intensity level for NMES applications to avoid discomfort?

Intensity should stay within the range of tolerable limits for the patient.