1.4 - electrical currents for muscle contraction

NMES (neuromuscular electircal stimualtion)

the __________ type of electrical stimulation is for innervated muscle

FES (functional electrical stimulation)

the __________ type of electrical stimulation is for innervated or denervated muscle

EMS (electrical muscle stimulation)

the __________ type of electrical stimulation is for denervated muscle

NME (neuromuscular electircal stimualtion)

the ____________ type of electrical stimulation is where an intact peripheral nerve depolarizes first to initiate skeletal muscle contraction

FES (functional electrical stimulation)

the ____________ type of electrical stimulation is where it depolarizes the muscle itself

strength and reeduction

what is the goal of NMES (neuromuscular electrical stimulation)

facilitate or enhance functional movement

what is the goal of FES (functional electrical stimulation)

pressure muscle while nerve regenerates (controversial)

what is the goal EMS (electrical muscle stimulation)

intact; functioning

NMES requires _________ and _________ peripheral nerves

NMES

indications for the use of __________ electrical stimulation:

• Strengthen muscles

• Enhance muscle recruitment

• Facilitation of weak, inhibited muscles

• Slow down or prevent muscle atrophy

• Decrease spasticity

• Control edema

• Restore function

NMES

__________ electrical stimulation is the use of electrical currents to produce muscle contractions in innervated muscle

superiorly

you should see the patella glide _________ when you stimulat the quads with NMES

F (type 1 are activated first before the larger muscle fibers)

T/F: type 2 fibers are contracted before type 1 fibers with a physiologic/voluntary muscle contraction

2 (opposite of a voluntary contraction which stimulates type 1/smaller fibers first)

NMES stimulate type ____ fibers first

voluntary contraction (bc it stimulates type 1 first, not type 2)

NMES or voluntary contraction:

fatigue and atrophy resistant

NMES

NMES or voluntary contraction:

contraction is rapid, jerky onset

NMES

NMES or voluntary contraction:

fatigues and atrophies quickly

voluntary contraction

NMES or voluntary contraction:

contraction is slow and at a low force

NMES

NMES or voluntary contraction:

synchronous recruitment

voluntary contraction

NMES or voluntary contraction:

asynchronous recruitment

2 first, then 1

postinjury, decline in strength is predominantly due to which of the following?

1. number of motor units recruited

2. frequency that motor units are recruited

3. recruitment in a more synchronized manner

F (it does both, yay!)

T/F: NMES improves strength but not motor unit recruitment

be able to activate it first (motor unit recruitment, hint, NMES)

before you can build the muscle, you need to…….

physiological contractions

NMES can increase muscle strength and endurance when used with ____________

strength

to increase _________ with NMES greater-force contractions is used

endurance

to increase _________ with NMES prolonged stimulation with lower force contractions is used

amplitude and pulse duration (more force)

to increase strength with NMES you can adjust the _________ and _________ parameters on the machine

yep!

does the evidence support the claim:

ACL injuries/repairs see greater strength gains with NMES and exercise than exercise alone

first

the evidence says that the strongest NEMS effects are found when applies after the _______ week post repair/reconstruction of ACL

if they are performed at the same intensity

the evidence says that NMES and voluntary contraction are equally effective under what condition?

F (NMES does accelerate recovery but does not alter the outcomes)

T/F: NMES can accelerate ACL recovery and produce better outcomes compared to not using NMES

1

the evidence shows that COPD patients that received NMES had an increase in type _____ fibers

NMES and FES

evidence shows that patients with CNS damage can benefit from _______ and _______ electrical stimulation

5; 7 (trigeminal and facial)

cranial nerve pop quiz:

feel with CN _____ and move with CN _____

reinnervation

EMS can preserve muscle denervated muscles when ___________ is anticipated

F

T/F: NMES can add an extra benefit to strength training in healthy individuals

• Cardiac pacemakers/electronic implants

• Unstable arrhythmias

• Malignant tumors

• Over carotid sinus/ant. neck/head*/reproductive organs/chest

• Active DVT or thrombophlebitis

• In area of hemorrhage or active infection

• Over damaged skin; recently radiated skin

• Pregnancy (over/near abdomen or low back)

• any unstable area due to recent surgery, fx, or osteoporosis

• lower abdomen

10 contraindications for estim

• Impaired sensation

• Impaired circulation (some sources list this as a contraindication for NMES)

• Impaired mentation

• Skin disease/irritation

• Neuropathies/denervation

• Active epiphysis

• Cardiac disease

7 Precautions to estim

larger

NMES symmetrical biphasic pulsed waveform is more comfortable for (smaller or larger) muscles

smaller

NMES asymmetrical biphasic pulsed waveform is more comfortable for (smaller or larger) muscles

asymmetrical (remember this is more comfortable for smaller muscles)

studies have shown that (symmetrical or asymmetrical) biophasic pulsed waveform for NMES to be more effective

russian

_________ waveform is a continuous wave of AC broken into bursts of many cycles grouped together

T (none because it is AC current)

T/F: there is no pulse duration for russian NMES parameters

350-450 micro sec

the optimal starting pulse duration for NMES is _____-______

higher

the (lower or higher) the pulse duration → the more effective

frequency

the goal of adjusting the __________ of the waveform is for a smooth, forceful contraction

30-50 pps

the general range for frequency of a NMES waveform is _____-______

amplitude; pulse duration

the _____________ and ______________ parameters should be set at max/highest tolerated

less

the longer the ramp the (less or more) total activation time

50

russian is produced with a _____% duty cycle but you can still have on:off times

10

the time/duration parameter is at least ______ contractions

2500 Hz

what is the frequency set to for Russian protocol

10; 50

what is the cycle time for Russian protocol, ______ on and ______ off

10 min

what is the total tx time of Russian protocol

max tolerable

what is the intensity set to for Russian protocol

• monopolar

• bipolar

• quadripolar

what are the 3 configurations for electrodes

bipolar

___________ is the most common type of configuration

• 1st on motor point

• 2nd parallel with fiber direction

where are the electrode pad placements for a bipolar electrode configuration

T

T/F:  Several attempts may be needed to optimize the electrode placement

10

about ______% of the population is unable to tolerate NMES