Transcutaneous electrical nerve stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain. A small device delivers the current at or near nerves. TENS therapy blocks or changes your perception of pain. Strength duration curve

1. TENS
©2020 ROHIT BHASKAR PT 1
Presented By
Rohit Bhaskar PT
At Uttar Pradesh University
Of Medical Sciences

2. ©2020 ROHIT BHASKAR PT
▪ Transcutaneous Electrical Nerve Stimulation (TENS) is a
method of electrical stimulation which primarily aims to
provide a degree of pain relief (symptomatic) by
specifically exciting sensory nerves and thereby
stimulating either the pain gate mechanism and/or the
opioid system.
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3. MECHANISM OF ACTION
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▪ Possible Pain-Relieving Mechanisms;
▪ Activation of ‘pain-gating’ mechanisms.
▪ Stimulation of the descending pain suppression system
and endogenous opiate mechanisms.
▪ The Central Biasing Theory
▪ Removal of the substances which stimulate pain nerve
endings from within the damaged area
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4. PARAMETERS USED FOR TENS
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▪ Waveforms
▪ Frequency or Rate
▪ Pulse width or Duration
▪ Amplitude or Intensity
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5. FREQUENCY OR RATE
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▪ High Frequency (80-120):
▪ Large myelinated fibers respond effective > 100Hz
▪ Immediate relief of pain
▪ Acute pain
▪ Low Frequency (1-20):
▪ Small unmyelinated fibers respond effectively at <100Hz
▪ Increase endorphin production, thus analgesia following
stimulation
▪ Chronic pain 5

6. PULSE WIDTH OR DURATION
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Pulse width Indications
50μs Large myelinated fibers
(sensory touch)
100 - 150μs Normal neuromuscular system
200 μs Small myelinated fibers
200 – 300 μs Patients with neurological damage
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7. AMPLITUDE OR INTENSITY
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▪ TENS units intensity ranges form 1 mA to 100 mA
▪ TENS is only effective when the patient actually feels the
stimulus
▪ Patients need to increase the intensity when the body
accommodates to the stimulus (when they don’t feel the
stimulation anymore)
▪ Dying batteries can cause fading intensities
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8. TYPES OF TENS
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▪ Conventional TENS or High Frequency TENS
▪ Acupuncture-like TENS (AL-TENS) or Low Frequency TENS
▪ Brief TENS or Intense TENS
▪ Burst TENS
▪ Modulated TENS or Modified TENS
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9. CONVENTIONAL OR HIGH TENS
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▪ Frequency – 50 Hz to 100 Hz
▪ Pulse Width – 20 μs to 60 μs
▪ Intensity – (0 mA to 30 mA).
▪ The intensity until a prickling or tingling sensation is felt.
▪ Principle –Presynaptic inhibition by pain gate
mechanism by stimulating Aα and Aβ fibres.
▪ Duration – 30 to 60 minutes once or twice daily.
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10. ©2020 ROHIT BHASKAR PT
▪ Frequency – 1 Hz to 4 Hz
▪ Pulse Width – 150 μs to 250 μs
▪ Intensity – 30 mA to 60 mA.
▪ applied to acupuncture points or motor points of muscle in the
segmentally related myotome.
▪ Principle –This stimulates the high threshold Aδ and C fibres, which
lead to release of endogenous opioids and provides further sensory
input from muscle spindle afferents (chemical theory).
▪ Duration – 20 to 30 minutes once a day.
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Acupuncture or Low TENS

11. BURST TENS
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▪ Burst TENS is a series of pulses (i.e. a train), repeated 1- 5
times a second, commonly twice.
▪ Each train or burst consists of a number of individual pulses
at the usual conventional TENS frequencies of 50 Hz to 100
Hz but at higher intensity.
▪ It combines both the conventional and acupuncture-like
TENS and
▪ therefore provides pain relief by both routes.
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12. BRIEF OR INTENSE TENS
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▪ Frequency – More than 100 Hz
▪ Pulse Width – 150 μs to 250 μs
▪ Intensity – Highest level tolerated by the patient.
▪ Principle –Activity in cutaneous Aδ afferents induced by
intense TENS produce peripheral blockade of nociceptive
afferent activity (Central biasing mechanism).
▪ Duration – 30 to 60 minutes once or twice daily.
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13. MODULATED OR MODIFIED TENS
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▪ In modulated TENS the pulse length, frequency, and
amplitudes can be constantly and automatically varied.
▪ This cyclical variation is believed to prevent adaptation of
the nerves to the current (no accommodation)
▪ is particularly appropriate as a variant of conventional
TENS used over long periods.
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14. CONTRAINDICATION
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▪ Someone with a pacemaker
▪ Someone with undiagnosed pain.
▪ Someone with a heart condition
▪ On head or neck of someone with epilepsy
▪ Someone with venous or arterial thrombosis or thrombophlebitis
▪ Someone with indwelling phrenic nerve or urinary bladder
stimulators
▪ Near operating diathermy device
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15. CONTRAINDICATION
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▪ Around the head
▪ On the eyes
▪ Over mucosal surfaces
▪ Using electrodes on infected skin
▪ Electrodes across the chest of a patient with cardiac disease
▪ Electrodes should not be placed near carotid artery in the
anterolateral region of the neck. There is a potential risk that
stimulation at this site might cause heart block by exciting the
vagus nerve.
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16. PRECAUTIONS
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▪ Areas of skin irritation, damage or lesions
▪ Areas with impaired sensation
▪ Over abdominal, lumbosacral or pelvic regions during pregnancy
other than for labor/delivery
▪ Tissues vulnerable to hemorrhage or hematoma
▪ Athletes should not be permitted to participate in sports while
under the influence of TENS analgesia
▪ Extreme caution is needed with patients taking narcotic
medication or who are known to have hyposensitive areas.
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17. PRECAUTIONS
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▪ Incompetent patients may not be able to manage the device and it
must be kept out of reach of children.
▪ For patients with diagnosed malignancies that have been
diagnosed as terminal, TENS can be used for pain control with
informed consent of the patient.
▪ Otherwise, TENS should not be used when malignancies are
present.
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18. THANKYOU
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