WK6- NMES, FES, EMS Flashcards
What are the differences between NMES, FES, and EMS
NMES: activation of skeletal muscle for strengthening, re-education or edema reduction; depolarization of peripheral nerve to create a muscle contraction
FES: activation of skeletal muscle for functional usage, may be used on innervated or denervated muscle
EMS: implies the stimulation of denervated muscle
What is the primary difference between NMES and EMS ?
The type of tissue stimulated
NMES stimulates nervous tissue, EMS aims to simulate muscle tissue
When the neural system is intact distally what ES options are recommended? When the neural system is not intact what ES option should you consider ?
NMES and FES
EMS
Define NCS and EMG
NCS= nerve conduction study that assess motor and sensory nerve function using surface electrodes
EMG: electromyography study that looks at the integrity of muscle/nerve complex.
What are the general goals of using NMES for strengthening and re-education ?
prevent or treat muscular atrophy following disuse, immobilization, or detaining
increase or maintain ROM
re-education, retrain, or facilitate muscle for movement or posture.
True or False. There poor to moderate evidence supporting NMES use for strengthening of weakened muscle.
False. NMES has been proven to increase muscle size and motor unit recruitment
What other conditions have been shown to benefit from NMES?
Post Knee surgery: ACL, TKA, knee ligament and meniscal tears, best when used early in rehab
Knee OA, PFS, atrophy associated with RA
COPD, heart failure, thoracic cancer, cardiothoracic surgery
What is the evidence for NMES for strengthening in neurological poplulations ?
stroke, cerebral palsy, SCI, MS studied
best evidence for stroke
enhances strength, ROM, and function
How does NMES increase ROM in neurologic populations?
stimulation of antagonist leads to increased length of agonist
What are the three theories for the usage of NMES for treatment of spasticity?
spasticity is velocity dependent increase in tone ( UMN)
- stimulate antagonist- NMES applied to the antagonist muscle decreases spasticity through reciprocal inhibition of the spastic agonist muscle. It occurs through inhibitory interneurons with in the spinal cord.
- stimulate agonist- NMES applied to the spastic agonist muscle works by fatiguing the muscle or by providing recurrent inhibition via Renshaw cells which when stimulated inhibit the spastic muscle cell.
- habituation of sensory input- ES when delivered only at sensory levels leads to sensory habituation that then leads to a decrease in spasticity
What are the specific precautions of implanted sacral stimulators for urinary incontinence ?
pregnancy or planning to be pregnant, infections or lesions, prolapsed uterus, recent pelvic surgery
What is the correct placement of the electrodes for NMES ?
One electrode goes directly over the muscle to be stimulated and one over its motor point running parallel to the muscles fibers.
may need to be adjusted for desired effect.
What are the 3 common waveforms used for NMES ?
Pulsed Bi-phasic, Russian, Aussie
What is the general rule when choosing an amplitude ?
highest tolerated pulse duration/ amplitude but ideally should meet or exceed 50% of max volitional contraction
What is the common frequency used in NMES ?
30pps or 20-30 for small muscles
When using NMES for the reduction of spasm and increase of ROM what is the recommended on and off time ?
1:1 ratio
When using NMES for strengthening what is the recommended duty cycle/ on and off time ?
10% to 50% duty cycle
1:5
1:3
What are the parameters for NMES and FES with the goal of muscle strengthening. Include waveform, pulse frequency, pulse duration in microseconds, amplitude, duty cycle, duration.
Goal: Muscle Strengthening
Type: NMES
Waveform: Biphasic PC or burst modulation ( Russian or Aussie)
Pulse Frequency: 20-80 pps depending on muscle size
Pulse Duration: 200-600 microseconds depending on muscle size
Amplitude: As high as tolerated while reaching 50% MVC
Duty Cycle: 1:3, 1:5 with on-time up to 10sec off and time up to 50 sec
Duration:10-20 strong contractions o rup to 1hr/day, 3-5x/week, 4-8 weeks
What are the parameters for NMES and FES with the goal of muscle spasm reduction or improvement of tissue extensibility. Include waveform, pulse frequency, pulse duration in microseconds, amplitude, duty cycle, duration.
Goal: Tissue extensibility/ - muscle spasm
Type: NMES
Waveform:Biphasic PC or burst modulation ( Russian or Aussie)
Pulse Frequency: 35-50 pps
Pulse Duration: 125-250 microseconds depending on muscle size
Amplitude: to visible contraction
Duty Cycle: 1:1, ramp up and down 1-5 sec
Duration: 10-30 min, 1-4x/week, 2 weeks-6 months
What are the parameters for NMES and FES with the goal of muscle contraction for functional use. Include waveform, pulse frequency, pulse duration in microseconds, amplitude, duty cycle, duration.
Goal: Muscle contraction for functional use
Type: FES
Waveform:Biphasic PC or burst modulation ( Russian or Aussie)
Pulse Frequency: 20-60 pps
Pulse Duration: 200-600 microseconds depending on muscle size
Amplitude: matching functional usage
Duty Cycle: depends on activity
Duration: task specific
What is the difference in motor unit recruitment when done volitionally compared to NMES.
normally the body recruits small type I fibers which take longer to fatigue, however motor recruitment is random in NMES and therefore can lead to faster fatigue and increase DOMS
True or False. Line powered simulators are recommended over battery powered NMES machines.
True.
How can NMES help reduce swelling associated with edema ?
repetitive muscle contractions compress veins and lymph vessels, reduce swelling and increase venous and lymphatic return using a symmetrical or asymmetrical biphasic PC or Russian current.
What are the NMES parameters for subacute and chronic edema management ?
Type: NMES
Waveform: biphasic PC or Russian or Aussie
Pulse Frequency: 20-80 pps
Pulse Duration: 100-600 microseconds
Amplitude: mA to tetanic contraction
Duty Cycle: 1:1 on: off ratio, on 2-5 seconds, off 2-5 seconds, equal on: off times: 1 sec ramp up and down time.
Duration: 10-20 minutes of rhythmic contractions, 1-2x/day, monitor edema
What are the general recommendations of EMS for denervated muscle ?
long pulse durations, higher intensity, Direct current
What are the parameters for EMS usage for denervated muscle?
Pulse Duration: 1-450msec
Frequency: 1-500pps
Amplitude: high enough to obtain contractions but low enough to prevent burns
Ramp up and down time: not specified
Duty cycle: Variable, on time 3-10 sec and off time 30-50 seconds
Treatment time and duration: 30 min/8 hours per day; 5-7 days/week; 4 days to 4 years
