Electrical Stimulation Flashcards
What can electrically stimulated do to muscles?
Strengthen
Improve endurance
Prevent muscle atrophy
Reduce spasticity
Help Restore function
(Improve cardiovascular health (Bonus))
When using electrical stimulation which muscle fiber is recruited 1st?
Fast twitch type II
What is the order of recruitment in normal muscle contraction?
Slow twitch type I fibers activated 1st
Followed by larger sized, faster motor units
Describe the graduation of contraction when electrically stimulated
Rapid/jerky b/c all motor units under pad fire once stimulated
Describe gradation of normal contraction
Gradual increase of force in smooth manner
Which fibers are more resistant to fatigue and atrophy?
Type I
Which fibers fatigue rapidly & prone to weakening & atrophy w/ disuse?
Type II
What is the clinical importance that electrical stimulation will recruit type II fibers first?
Longer rest time should be provided (more fatiguing)
Why should patients perform physiological contractions w/ electrically stimulated contraction?
Optimize recruitment
Functional integration
What is the ratio stimulation to rest time that should be done?
1:5
When using electrical stimulation describe the order from A beta fibers to denervated muscle that will be stimulated
A beta
Motor
A delta sharp pain
C dull pain
Denervated muscle
What is the clinical implication of nerve disease or injury?
Denervated muscle can no longer contract (physiologically or electrically)
In cases of denervated muscles what can be done to cause contraction?
Direct current is applied directly to muscle belly, stimulating AP in muscle cells directly w/o input from motor nerve
What can be an issue of direct current to denervated muscles?
Slows down nerve regrowth drastically
What are some clinical application of electrical stimulation for muscle contraction?
Orthopedic conditions
Cardiorespiratory
Healthy adults & athletes
Muscle coordination & motor control for patient w/ neurological conditions
Is NMES added to functional program before surgery shown to increase post - operative strength & faster functional improvement
YES
True or False: Higher NMES training intensities were associated w/ greater quad muscle strength & activation after TKA
True
What effect can NMES have on patients with OA?
Decrease pain
Increase quad strength
improve walking & climbing
What effect can NMES have on patients with RA?
Improve strength & endurance
What did a study show to do when NMES was applied to quads in patients w/ heart failure?
Improved:
Peak O2 uptake
6 min walk test distance
Muscle strength
Depressive sxm
QoL
In patients with critical illness what kind of effect did NMES have on them?
Regains strength 4.5 times faster than patients in control group
What effect did NMES have on healthy adults & athletes?
Generally improved strength
Inconsistent impact on functional performance
Following a stroke what can NMES do?
Improve strength & activity
Prevent or reduce shoulder subluxation & improve function
Reduces spasticity & increased ROM
What Neurological disorders cam NMES be used for?
Spinal Cord Injury
Multiple Sclerosis
Cerebral Palsy
Dysphagia
Urinary Incontinence
What are some contraindication of NMES?
When muscle contraction of the muscles may disrupt healing
What is precaution of NMES?
May cause DOMS
What are the parameters to Russian Electrical Stimulation?
Pulse Duration: 200-800 usec
Frequency: 30-100 Hz
Amplitude: To max contraction
Treatment Time: 10 sec on/ 50 sec off
Ramp on/off time: 1-2 sec
What are the parameters for Waveform- Symmetric biphasic?
Pulse Duration: 200-800 usec
Frequency: 20-60Hz
Amplitude: To max contraction
Treatment Time: 10 sec on/ 50 sec off
Ramp on/off time: 1-2 sec
How should the electrode be placed for NMES?
One over motor point & other on muscle to be stimulated
Electodes should be placed at least 2 inches apart
What kind of pulse duration are more comfortable for smaller muscles?
Shorter
What kind of pulse duration are more comfortable for larger muscles?
Longer
What needs to be increased as pulse duration is shortened?
Amplitude
What is the first thing you change if the stimulation is uncomfortable?
Pulse duration
What will a low frequency cause?
each pulse will produce a separate twtitch contraction
What can accrue as frequency increases to about 30-50 pps?
Twitches occur closer together eventually summating into smooth titanic contraction
What can frequency of 50-80 pps cause?
Stronger muscle contraction but results in faster fatigue
When can electrical stimulation be used to control edema & improve circulation?
When caused from lack of muscle activity
What is TENS?
Method of nerve stimulation
What does TENS do?
Activate:
Gate control theory
Descending pain control theory
Endogenous Opiate Theory
What does Conventional TENS (high rate or high frequency) use?
Short duration, high frequency biphasic pulses at a current amplitude sufficient to produce comfortable sensation w/o muscle contraction to selectively stimulate nociceptor A beta nerves & activate gating mechanisms
How does TENS activate the descending pain control theory?
- Intense electrical stimulation of A delta & C fibers cause stimulation midbrain, pons & medulla
- Release enkephalin through depending neurons which blocks pain impulses at spinal cord level
- Cognitive input from cortex relative to past pain experience contributes as well
What does Low Rate or Low Frequency TENS use?
Low frequency pulses at rate high enough to produce motor contraction using repetitive stimulation of motor nerves to produce brief repetitive muscle contraction (twitches) to stimulate endogenous opioid production & release & increase opioid binding receptor potential
Why is high rate TENS more effective than low rate TEN in pts taking opioids?
Low rate TENS stimulate same receptors as opiods
Why may a patient that consumes a lot of caffeine not feel analgesic effect of high frequency TENS?
Caffeine (200 mg) can block effect b/c is it a competitive adenosine receptor antagonist
How long can low rate TENS control pain?
4-5 hrs after 20-30 minute treatment
What can happen if you apply the same parameter of TENS over and over again?
Pts may develop tolerance
When is high rate TENS recommended to use?
When sedation but not muscle contraction will be tolerated
Acute injury w/ inflammation or tissue may be damaged by contraction
When is Low rate TENS recommended to use?
When longer duration of pain control is desired & muscle contraction is likely to be tolerated
More analgesia at 5 & 15 min post application
Is TENS recommended for neck pain?
Might not be best option
Is TENS found to be effective in the knee?
No
What is the effect of TENS on acute pain?
Produced clinically significant reduction in pain severity for patients w/ moderate to sever acute pain
Reduced anxiety secondary to pain
What is the effect of TENS on chronic pain?
No clue b/c so many factors
What is IFC?
TENS application of 2 medium frequency that alternate
Cross 4 pads
How should a patient be positioned when TENS is applied for acute pain?
Positioned for comfort
How should electrode pads be placed for TENS?
Around painful area
Prox along sensory nerve when can’t be applied to painful area
1 inch apart
What should the current amplitude cause with High Rate TENS?
Strong tingling or vibration sensation
What should the current amplitude cause with Low Rate & burst TENS?
Muscle contraction that can be seen or palpated
What all should be documented with electrical stimulation?
Electrical Stimulation Type
Area of Body treated
Patient position
Electrode Placement
Specific Parameters
Treatment duration
Patients Response
Rational for treatment
