TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION (TENS) BY MINED ACADEMY

1. Transcuteneous electrical Nerve
Stimulation

2. Definition:
Transcuteneous electrical nerve stimulation (TENS) is the application of
low frequency current in the form of pulsed rectangular currents through
surface (pad) electrodes on the patients skin to reduce pain.

3. Phyaical principle of nerve fibres:
Nerve fibre
Large fibre
A- delta
C-fibre
Small fibre
A-alpha
A-beta

4. Cont.
 Small diameter contains a-delta(δ)& c fibres which are nociceptive fibres,
 Large diameter contails A-beta(β) and A-alpha(α) which rae non-nociceptive fibres.
 These large diameter fibres have low threshold of activation to electrical stimuli when
compared with small diameter fibres.
 The current amplitude needed to exite a nerve fibre decreases with their increasing pulse
duration and pulse frequency.

5. Type of TENS:
There are mainly three(3) type of TENS, these are-----
1. Conventional TENS / High TENS.
2. Acupuncture like TENS/ Low TENS
3. Intense TENS

6. 1. Conventional / high tens:
Electrical characteristics: (high frequency,low intensity)
 Amplitude / intensity: low
 Frequency: 100-250 pps / Hz
 Duration: 50-100 micro(µ)sec
 Pattern: continuous
 Pulse shape: Bi-polar asymmetric spike potentials

7. 2. Acupuncture like TENS/ Low TENS
Electrical characteristics: (low frequency,high intensity)
 Amplitude /intensity : high
 Frequency: less than 100 pps / Hz
 Duration: 100-500 micro(µ)sec
 Pattern: Burst
 Pulse shape: mono-phasic pulses

8. 3. INTENSE TENS
 Frequency: high
 Intensity: high
 Duration: 20-200 microseconds
 Pulse shape: monophasic

9. PAIN
 Pain can be defined as reponse related to actual or impending tissue damage from the initial
stimulus.
 Physiological pain is often accompanied by emotional overtones,somatic & autonomic effect.
 Stimulus that can cause pain:
1. Mechanical(pressure)
2. Electrical(shock)
3. Thermal(heat/cold)
4. Chemical
 There are 3 types of neurone which carry the pain from the periphery to the brain.These are:-
a) 1st order neurone
b) 2nd order neurone
c) 3rd order neurone

10.  There are two types of mechanism to justify the relief of pain achieved by the TENS:-
1. The GATE_CONTROLL Theory
2. The ENDORPHIN_RELEASE Theory
*The GATE_CONTROLL Theory has 3 different mechanism depending upon the 3 different TENS.
o Segmental Mechanism
o Extra segmental mechanism
o Peripheral mechanism.
** The GATE_CONTROLL Theory system having 4 distinct component:-
 Afferent neurone
 Neural interactions within the dorsal horn of spinal cord
 Transmission cells
 Descending controls from higher brain centre.

11. Afferent fibres in peripheral nerves:
 A-fibre: all A-fibres are having large diameter cell body(myelinated)
 A-beta(β)- myelinated,low threshold cutaneous,rapidly adapting mechano-
receptors,they don’t contribute to pain, receptive field is small,
 A-alpha:- myelinated, innervated in muscle spindle and golgi-tendon adaptors.
Ait determines proprioception. Diameter: 12-20 micrometer, velocity: 72-120 ms.
 A-delta :- mechanical and thermal nociceptor, having a medium threshold,
myelination is very thin.diameter of 1-6 micrometer, velocity: 5-36 ms.. It
carries sharp and phagic pain.

12. Segmental mechanism
 This mechanism is used to treat the pain by Conventional TENS / High TENS
 This type of Tens produce analgesia predominantly by a segmental
mechanism, thereby activity of A-beta(β) fibres inhibits ongoing activity in the
second order nociceptive neurons in the dorsal horn of spinal cord.
 It has been shown that activity in large diameter afferents inhibit the
nociceptive reflexes in animals. It also showed that Tens could significantly
reduce ongoing nociceptor cells activity in the dorsal horn cell when it applied
to somatic receptive fields. Conventional TENS analgesia located in the spinal
cord & it slightly combo of pre& post synaptic inhibition.

13. Diag. of segmental mechanism

14. EXTRA-SEGMENTAL MECHNISM
 This type TENS induce activity in small diameter afferents produce extra
segmental analgesia through the activation of stimulus which forms
descending pain inhibitory pathways,such as PAG & nRM and nRG.

15. Diag. of extra-segmental mechanism

16. PERIPHERAL MECHANISM
 This mechanism is followed by the INTENSE TENS.
 Its mainly used to treat peripheral nerves
 It mainly produce local relief
 It should not be applied more than 15 min.

17. ADVANTAGES OF TENS
 It is a non-invasive
 It is portable
 User friendly and safe to be used
 The change of battery and electrode are only the extra cost once the
machine is purchased.

18. Dis-advantages of tens
A chemical burn may occur
A number of patient fails to tolerate the sensation of
electrical stimulation & fail to respond to treatment.
Skin irritation

19. Indication of tens
 Low back pain
 Musculoskelital pain
 Arthritic pain
 Obstretic pain
 Fracture healing( only in conservative method)
 Post operative pain(if there is no metal implanted)

20. Contra-indications
 Over carotid sinus
 Open wound
 Over the mouth
 Near the eyes
 Cardiac pacemaker
 Pregnancy
 Haemorrhagic condition
 Patient with allergy
 Epilepsy
 Patient with sensory deficiency
 Uncommunicative patients(both verbal and expressional)

21. Wave forms of tens
 There is no definitive work or publications to support the claim
that one wave form is better than other
 Asymetrical biphasic and monophasic pulses are used in TENS
 The spike and square waveforms show most effectiveness bcs of
having a sharp rate of rise which mostly depolarizes the targated
sensory nerve

22. Parameters for optimal effect
There should be:
 Enough strong stimulation to stimulate CNS
 Stimulating should be suitable for proper placement of electrodes,free
of bony and hairy area
 Site of treatment should be related to the source segmentally as well
as site of pain
 Site should be anatomically distinct and specific.

23. Placement
 Placemnet of electrodes are still controversial. There is a basic thumb
rule which states that the anode should be placed distal to the
cathode.
 Cathode should be as proximal as to the representative spinal
segment
 Anode placement may be located at:
1. Acupuncture sites
2. Dermatome of involved nerves
3. Over painful spot
4. Segmentally related myotomes
5. over trigger points

24. Presented by : Arghya Nandi(PT)
BPT- NILD(WBUHS)
PROF. TRAINEE (PT)-
NILD,KOLKATA