TENS– TranscutaneousElectrical Nerve Stimulation

Question 1

TENS

Answer 1

TranscutaneousElectrical Nerve Stimulation:
• Application of low voltage electrical stimulation for pain control
• Stimulates sensory receptors
• Does not generally “cure the pain”. Manages the pain.
• Alternative therapy to medication
• Allows client to perform activities of daily life, home exercise.
• Increase quality of life in those with chronic pain

Question 2

equipment

Answer 2

• Device: portable, clinical
• Lead wires: polarity of wire (red or black) does not matter with TENS
• Electrodes: adhesive vs. carbon. Use either 2 or 4 electrodes

Question 3

Concept of Amplification

Answer 3

Pain is influenced by physiological, psychological, behavioral, cognitive, affective, and environmental factors

Question 4

Types of Pain

Answer 4

• Acute: rapid/sudden onset. Sympathetic response – Fight or Flight
• Chronic: More diffuse, all consuming, affects function; greater than 30 days
• Referred: in area other than original injury site. Hypersensitive areas; pain generally in the fascia

Question 5

1. Melzack & Wall’s Gate Theory

Answer 5

1965: Sensory Theory of TENS
a. Nocioceptive (Pain) nerve fibers are C fibers which are poorly myelinated and therefore travel slowly.
b. Sensory nerve fibers are A-beta fibers or Alpha A fibers which are highly myelinated fibers and therefore travel faster and bombard the hypothalamus .
c. Competition of the two fibers results in sensory stimulation blocking the lesser myelinated pain fibers.

Question 6

2. Endorphin Theory

Answer 6

Motor level theory of TENS (must create twitch)

a. Electrical stimulation increases levels of endorphins in central nervous and peripheral nervous system
b. TENS stimulates motor nerve which facilitates release of endorphins (endogenous opiates) from the pituitary gland.
c. Believers of this theory feel the analgesic effect is systemic and long lasting.
d. Requires a minimum of 20 – 30 minutes of TENS to get the endorphin release

Question 7

other theories

Answer 7

a. Acupuncture theory – TENS alters flow of energy

b. Myofascial Theory- Tens stimulates local vasodilation which alters trigger point to decrease pain

Question 8

Conventional TENS

Answer 8

– sensory technique: good for patients with sharp well defined pain

• Pulse Frequency -> 50 – 100 pps
• Pulse Duration -> 50 – 100 micro-seconds
• Treatment time -> 15 – 30 minutes, all day, or when having pain (prn)
• Pulse amplitude -> (Dial) turn up until feels a tingling, tapping or pins & needles (without muscle twitch)

Question 9

Low Frequency TENS

Answer 9

– Motor or acupuncture technique: good for more diffuse, throbbing, burning pain

• Pulse Frequency -> 1-4 pps
• Pulse Duration -> 150 - 200 micro-seconds
• Treatment time -> 30 - 45 minutes
• Pulse amplitude -> place electrode over motor point: turn up until get a muscle twitch

Question 10

Noxious TENS

Answer 10

– Brief Intense Stimulation: rarely used due to very uncomfortable. Very low pulse frequency and duration. Hold on usually with a probe stimulator 30 seconds over point. Very aggressive, high skill level.

Question 11

Modulation Concept

Answer 11

Patients will accommodate over time if left on continuous setting. Once TENS set up need to choose an alternate setting (i.e. modulation, burst) which will deliver the stimulation in a random fashion to reduce accommodation.

Question 12

Electrodes

Answer 12

Looking to choose the correct size to achieve specificity of muscle and enough penetration
• Carbon: Need gel or wet sponge as transmission medium
• Polymer Self adhesive: Can re-use; watch for loss of stickiness. Rehydrate & reapply to plastic between use, store in Ziploc pouch. Too old: creates skin problems due to uneven current density
• Disposable: Like bandaide, readhesive not great. One time use.
• Sizes: 1 inch, 2 inch, 3 inch, can cut down (avoid wire) to size. 2” most common with upper extremity

Question 13

Current Density

Answer 13

Electrical current per unit area. The smaller the electrode the higher the current density (delivering same amount of current but to a smaller area)

Question 14

Smaller Electrode:

Answer 14

• greater current density so may not need to turn amplitude up as far to get response
• Targets the stimulation and therefore cuts down on overflow to adjacent tissue
• Increased chance of burning or galvanic response if less than 1 inch

Question 15

ectrode Placement Choices

Answer 15

• Identify the area of worst pain (other areas are generally referred pain) and place one electrode here and one proximal
• Determine the sensory dermatone pathway and place electrodes within the dermatone, at least one proximal
• Over a motor point or acupuncture point (use a chart)

Question 16

Patterns of Placement

Answer 16

• Proximal: Between Pain and Brain!
• Parallel: on either side of an incision site or scar
• Crossed method: use of 4 electrodes on 4 corners with worst pain in the center
• Unilateral , linear, and overlapping with distal point
• Contra-laterally: trait opposite side: used to treat phantom pain or RSD patients who can’t tolerate

*Place at least one electrode apart
Too close: get higher current density at surface and therefore skin reaction
Penetration depth is directly related to the distance of the electrodes (if you spread apart you get deeper penetration)

Question 17

Resistance to current

Answer 17

dirt, sweat, lotion. Get in habit of cleaning skin (not soap: drying), hair (cut do not shave), dry skin, poor contact/old electrode

Question 18

common uses:

Answer 18

Acute Chronic pain
Phantom Limb Pain
Post operative pain
Obstetric pain
Neurologic Pain: Shingles
Potential Painful treatments

Question 19

Contraindications and Precautions

Answer 19

general electro-modality

Question 20

application

Answer 20

• Position in a place of relaxation, ask questions, inspect skin, remove creams, lotions that limit penetration. Assess pain level before treatment.
• Explain procedure, describe sensation, potential benefits
• Place electrodes
• Set to continuous
• Select parameters: pulse frequency and pulse duration
• Turn machine on slowly increasing amplitude until patient reports sensory response
• Adjust to one of other settings (burst, modulated, etc) to prevent accommodation
• Train patient to turn amplitude up or down for comfort and for accommodation
• Evaluate effectiveness with a pain scale and or ability to complete functional task.