Transcutaneous Electrical Nerve Stimulation (TENS) is a non-invasive pain relief method that activates sensory nerves to stimulate pain-inhibiting mechanisms. It employs various parameters such as frequency, pulse width, and intensity to cater to different pain types, from acute to chronic. Precautions must be taken for certain medical conditions and skin sensitivities when using TENS devices.

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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