Transcutaneous Electrical Nerve Stimulation TENS

Question 1

What is TENS

Answer 1

Pulsed electrical current

Question 2

What is TENS used for

Answer 2

Pain relief and NOT muscle contraction/stimulation

ALSO⁣⁣⁣⁣⁣ it is the most comfortable modality due to CC-type stimulators (amplitude is constant)

Question 3

In general for TENS:

Type of current ?

Waveforms?

Pulse frequency range?
- which is for chronic or acute

Current amplitude range?

Pulse duration range?

Burst frequency range?

Treatment duration ?

Answer 3

Current type: Pulsed

Waveforms:
- biphasic symmetrical
- biphasic asymmetrical

Pulse frequency : 1-200 HZ
- high frequency : acute pain
- low frequency: chronic pain

Current amplitude: 0-120 mA

Pulse duration: 50 - 400 μs

Burst frequency: 5-10 pulses

Treatment duration: 5-10 minutes

Question 4

Conventional TENS

• acute or chronic pain?
• high or low frequency
• long or short duration?
• what does it stimulate ?
• long or short pulse duration?
• pulse rate/frequency ?
• intensity/ amplitude
• mechanism
• target nerve
• sensation
• time of treatment
• onset of pain relief
• length of pain relief

Answer 4

Acute pain

High frequency

Short duration

Stimulates sensory

Short pulse duration (<150 ms)

Pulse frequency : High freq (> 80Hz)

Intensity: comfortable + sensory only

Mechanism: gate theory

Target nerve: large A beta

Sensation: comfortable (pins and needles + tingling + no or minimal muscle contractions)

Time of treatment: minutes or hours

Onset of pain relief: rapid within minutes (5 minutes)

Length of pain relief: short lasting (less than few hours)

Question 5

Acupuncture TENS

• acute or chronic pain?
• high or low frequency
• long or short duration?
• what does it stimulate ?
• long or short pulse duration?
• pulse rate/frequency ?
• intensity/ amplitude
• mechanism
• target nerve
• sensations:
• time of treatment
• onset of analgesia
• length of pain relief

Answer 5

Chronic pain

Low frequency

Long duration

Sensory AND motor (can cause contractions)

Long pulse duration (>150 ms)

Pulse frequency : LOW freq (<80 Hz)

Intensity: comfortable/tolerable + sensory/motor

Mechanism: endogenous opiates

Target nerves:
- A alpha
- large A beta
- small A delta
- C pain fibers

Sensations : tingling WITH muscle contraction

Time of treatment: < 60 minutes

Onset of pain relief: slow within hours ( starts after 15 minutes)

Length of pain relief: long lasting analgesia ( > few hours)

Question 6

Burst train TENS

• what is it
• frequency
• what does it stimulate
• intensity/amplitude
• sensation
• which nerve fibers are activated
• mechanism:
• onset of pain relief:
• length of pain relief :
• treatment time:

Answer 6

(Hint: similar to acupuncture)

• delivery of bursts of pulses
• low frequency (<10 bursts per second)
• sensory AND motor stimulation
• as tolerated by patient
• tingling and moderate muscle contraction
• A delta , motor alpha, C fibers
• mechanism: opiate system
• onset of pain relief: slow (within hours)
• length of pain relief: long period (more than few hours)
• treatment time: 15-60 minutes

Question 7

Brief intense TENS

• pulse duration long or short
• frequency
• sensation
• intensity
• targeted nerves
• mechanism:
• onset of pain relief:
• length of pain relief :
• treatment time:
• when is this used ?

Answer 7

Long pulse duration (>150 ms)

High frequency (>80 Hz)

Sensation: noxious stimulation (can cause pain) + STRONG muscle contractions

Intensity: maximum tolerable pain

Targeted nerves: A beta , A delta , C nerve fibers

Mechanism: opiates system

Onset: rapid (within minutes)

Length of pain relief: long lasting (>few hours)

Treatment time: less than 15 minutes

Used before painful procedures (before strong massage, manipulations, or removing stitches)

Question 8

Modulated TENS

Answer 8

Question 9

Sizes of electrode

Answer 9

Small electrode = small localized area

Large electrode = large areas (reduce risk of tissue damage)

Question 10

Shapes of electrodes

Answer 10

Square
Rectangular
Round

Question 11

Types of electrode

Answer 11

Carbon

Silicon rubber (covered with gel)

Self adhesive (no need for medium)

Question 12

How to attach electrodes

Answer 12

Surgical tapes
Self adhesive electrodes
Straps

Question 13

Electrode preparation

Answer 13

Thin and evenly distributed coating of gel is applied to each electrode to OPTIMIZE CONDUCTION at the electrode-skin interface

Question 14

Channel units

Answer 14

Single channel unit:
- one pair of electrode
- single amplitude parameter
- small areas of pain

Dual channel unit:
- 2 output channels
- 2 variable amplitude parameters
- 2 pairs of electrodes
- diffuse large areas of pain

Question 15

Indication

Answer 15

ACUTE and CHRONIC pain
- post operative pain
- labor pain
- low back pain
- arthritis
- neuralgia
- myalgia
- cancer pain (not direct on tumors)

Question 16

Why is it ok to use tens on cancer patients?

Answer 16

Because it is superficial current

Question 17

General contraindications

Answer 17

Question 18

Local contraindications

Answer 18

Question 19

Electrode placement:

Within or around are of pain

Answer 19

Question 20

Electrode placement:

Spinal cord segment

Answer 20

Question 21

Electrode placement:

Spinal cord segment

Answer 21

Question 22

Electrode placement:

General limb pain

Answer 22

Question 23

Electrode placement:

Over specific body points (trigger points)

Answer 23

Question 24

Treatment time

Answer 24

Low rate : 20 - 30 minutes

High rate: 10 minutes to hours

(Inadequate time = failure and poor pain relief)

Question 25

Advantages of TENS

Answer 25

Administered easily
Can be used at home or work
Non invasive
No side effect
Affordable

Question 26

Source of poor results

Answer 26