NMES: Neuromuscular Eletrical Stim

Question 1

What is NMES used for?

Answer 1

Electrical current for muscle contractions

Question 2

Muscle contraction with electrically stimulated contraction

Answer 2

Muscle fiber type: fast type II
Recruitment: Synchronous
Speed of contraction: Fast
Fatigue: Fatigues quickly

Question 3

Muscle contraction with Physiologically initiated contraction (you do it yourself)

Answer 3

Muscle fiber type: Slow twitch type I
Recruitment: asynchronous
Speed of contraction: Slow
Fatigue: fatigue resistant

Question 4

Which type causes muscle to fatigue faster & require a longer rest period?
(Estim or Physiological)

Answer 4

E Stimulated contraction

Question 5

Indications for electrical stimulation for muscle contraction

Answer 5

• muscle strengthen for pt’s w/ orthopedic conditions (activating quads after surgery)
• cardioresp & functional training for pt’s w/ cardiac, pulmonary, or critical illness
• improve muscle coordination & muscle control in patients with neurological conditions (strokes, TBI’s, etc) (like drop foot & wrist extension with gripping)
• edema control for lack of motion & improve circulation (elevate while applying)
• slow atrophy (especially in denervated muscles)
• improve denervated muscle
• decrease atrophy in astronauts
• it should NOT be a substitute for exercise

Question 6

Contra indications for ALL E Stim (only when present in area of treatment)

Answer 6

• demand cardiac pacemaker/implantable defibrillator/unstable arrhythmia
  (Do not use in the vicinity of these devices)
  (Only use in the extremities with prior approval from physician responsible for devices)
• carotid sinus
• venous/arterial thrombosis or thrombophlebitis (DVT)
• pregnancy (low back/abdomen)

Question 7

Contraindications specific to NMES & Russian Stim

Answer 7

• do not use electrically stimulated muscle contractions when muscle contractions may disrupt healing (e.g. muscle or tendon tear, overuse, acute injury)

Question 8

Precautions for ALL E-STIM

Answer 8

General:
- Impaired mentation

Only when present in treatment area:
- cardiac disease (monitor pulse, respiratory rate, and overall pt response)
- impaired sensation
- areas of skin irritation
- allergies to adhesives

Question 9

Precautions specific to NMES (only present in the area of NMES)

Answer 9

• malignant tumors
• areas of open wounds
• may cause DOMS

Question 10

Patient position for edema

Answer 10

• elevate involved body parts above heart level
• keep the comfort of joint in mind (full knee extension might be uncomfortable - unless working on ROM knee ext)
• avoid close packed position

Question 11

Electrical stimulation to improve muscle strength

Answer 11

• instruct them to perform voluntary isometric contraction against resistance during ON time
• going off the above^, sometime isotonic contraction thru safe ROM while machine is active
• should be no pain in healing/injured tissues
• avoid close packed positions

Question 12

Electrode placement

Answer 12

Place electrodes over largest part of muscle belly
- 1 electrode over motor point
- other electrode over same muscle
- apply them as FAR as possible (at a minimum distance apart should be greater than the size of the patch/electrode) b/c having them too close = current traveling superficially & not achieving desired stimulation on muscles

Question 13

Parameters: Pulse duration

Answer 13

Stimulating small muscles: 150-200 msec

Stimulating large muscles: 200-350 msec

(Lower pulse durations improve comfort)
(Higher pulse duration increases muscle activation/overload)

Question 14

Denervated muscles

Answer 14

• possible to stimulate, but have to go up to around 10 milliseconds
• this can be uncomfortable as you have to first stimulate the Adelta & C nerve fibers
• stimulating denervated muscle fibers - benefits only last treatment time

Question 15

Parameters: Frequency

Answer 15

35-50 Hz (or Pulses Per Second, pps)

• can be slightly higher for larger muscles (up to 80 Hz - but may result in greater fatigue)
• can be slightly lower for small muscles (as low as 20 Hz)
• less than 20 is just a twitch contractions & not effective for strengthening muscles

Question 16

Electrical stimulation for muscle contractions - NMES

Answer 16

• biphasic alternating current (AC), + and - side

Question 17

Electrical stimulation for muscle contractions - Russian Stimulation

Answer 17

• polyphasic alternating current (AC)
• 2500 Hz carrier frequency that is packaged into 10 millisecond burst, with 50 bursts per second
• recruits more A delta fibers, so less comfortable/tolerable
• should only be used on patients who tolerate NMES w/o discomfort but have not been getting desired muscle stimulation

Question 18

Muscle strengthening parameters

Answer 18

Pulse frequency: 35-80 pps
Pulse Duration: 150-200 for small muscles, 200-350 for larger muscles
On time: 6-10 seconds (1:5 then progress 1:3)
Off time: you choose, EX: you choose 8 seconds with ratio 1:5, then multiply (8 x 5) = 40 second off time
Amplitude: >10% of MVIC in injured; >50% MVIC in UNINJURED (max voluntary isometric contraction)
Ramp times 2-5 seconds (separate from treatment time itself)
Treatment time: 10-20 minutes to produce 10 reps then progress to 20 reps
Times per day: 2-3 hours when awake

Question 19

Overload principle - how can we increase?

Answer 19

• increase amplitude
• pads closer to each other
• increase pulse duration
• use larger electrodes (increases number of motor units activated when using larger pad)

Question 20

edema reduction

Answer 20

Pulse frequency: 35-50 pps
Pulse duration 150-200 ms for small, 200-350 ms for large
Amplitude: to visible contraction
On time: 2-5 seconds
Off time: 2-5 seconds
(Make them equal)
Ramp up/ramp down time: at least 1 second
Treatment time: aim for 30 minutes
Treatment frequency: 2 times a day if possible