physiotherapy educational pupose

1. A.THANGAMANI RAMALINGAM
PT, MSc (PSY), MIAP

2.  TENS is a method of electrical
stimulation which primarily aims to
provide a degree of symptomatic pain
relief by exciting sensory nerves and
thereby stimulating either the pain
gate mechanism and/or the opioid
system. The different methods of
applying TENS relate to these
different physiological mechanisms

3. Transcutaneous Electrical Neuromuscular
Stimulation
 Pain control treatment
 Can cause muscle contractions, but that is not
why it is used
 Decreases patient’s pain perception by
decreasing the conductivity & transmission of
noxious impulses from small pain fibers (effects
large diameter fibers)
 Moderate caffeine levels (200 mg, approx 2-3 c.
coffee) may decrease effectiveness of TENS

4. What is pain?
“An unpleasant sensory and
emotional experience associated
with actual or potential tissue
damage, or described in terms of
such damage” ISAP (1979)

5. DEFINITION
 Pain is a noxious unwanted perception in
which the patient seeks medical
intervention.
 “Pain is subjective, individual and modified
by degrees of attention, emotional state
and the conditioning of past experiences.”
(Livingstone 1943). The intensity of the
pain is not directly proportional to the
degree of suffering. Because it is basically
a psychological experience and depends
on how it is interpreted or experienced

6. TYPES
 Acute pain – shorter duration up to six months
 Acute monophonic pain
 Recurrent acute non-malignant pain
 Chronic pain – longer duration > six months
 Chronic malignant pain - progressive
 Intractable-benign
 Chronic pain associated with non-malignancy disease –
identifiable pathology
 Chronic non-malignant pain syndrome
 Recurrent acute – migraine
 Chronic and acute pain may have different causes –
behavioral factors may be involved in acute pain

7. PAIN RECEPTORS

8. How do we experience pain?
 Specificity theory – Desecrates
 posits that there are specific sensory receptors for different types of
sensations (i.e., pain, touch, pressure)
 Pattern theory – Melzack & Wall (1982)
 posits that pain results from the type of stimulation received by the
nerve ending and the key determination of pain is the intensity of
the stimulation
 Both theories have limitations
 pain can be experienced without tissue damage
 tissue damage can occur without pain being felt
 Phantom limb pain experience not accounted for by the theories –
Fordyce (1988) study of amputees

9. PHYSIOLOGY OF
PAIN
Receptors
A fibers – Localized and
quick type of pain C fibers
– Slow acting type of
pain(Peripheral Nervous
System)
Spinal Cord (Substantia
Gelatinosa)
Spinothalamic Tracts
(Lateral / Anterior)
Thalamus
Cerebral Cortex
(Somatosensory Cortex)
Influenced
by Limbic
system &
Reticular
formation

10. Gate Control Theory
 Gate control theory –
 Melzack & Wall (1965)
 severity of pain sensation determined by balance between
excitatory and inhibitory inputs to T cells in spinal cord
 C & A-delta nociceptor afferents give excitatory input to dorsal root
ganglion of spinal cord– A-delta (myelinated) about 40 mph and C
fibers (unmyelinated) about 3 mph, other sensory information
travels at about 180 -240 mph
 Substantia gelatinosa, large diameter A-beta non-nociceptor
afferents give inhibitory input
 Increased firing of non-nociceptor afferents causes presynaptic
inhibition of T cells and the spinal gate from excitatory cells to the
brain is closed. –
 Physical agent modalities and physical activities believed to close
the gate by activating the non-nociceptor afferents
 The theory does not explain pain modulation descending from brain

11. Central Control Mechanisms of Pain
 Not well understood
 Periaqueductral gray seems to be
involved in pain – electrical
stimulation can block the experience
of pain
 Spinothalamic tract which carries the
impulses up the spinal cord, through
the brain stem to the thalamus
 Cerebral cortex
 sensory area of parietal lobe: localization
and interpretation of pain - somatosensory
cortex
 limbic system: affective and autonomic
response
 temporal lobe: pain memory

12. The same part of the
brain – the anterior
cingulate cortex –
responds to physical
and emotional pain.
Where is pain in the brain?

13. Chemical processes involved in pain
 Substance P
Chemical mediator thought
to be involved with transmission of
pain.
Associated with inflammatory pain
It excites pain transmitting
neurons when released
Its mechanism is not fully
understood
 Glutamate – release affects
amount of pain experienced
 Prostaglandins, bradykinin –
released when tissue
damaged

14. Chemical processes involved in pain Endorphins
 Pain perception modulated by these opiate like
neurotransmitters
 The endorphins bind to certain sites on the nervous
system including peripheral nerves
 They suppress pain transmission at the spinal cord level
by inhibiting the release of the neurotransmitter gamma
aminobutyric acid (GABA) in the periaqueductal gray
matter (PAGM) and raphe nucleus of the brain
 High concentration of opiate receptors in limbic area of
brain explains the stress relief and euphoria associated
with opiates
 Limbic system involved with emotional component of pain

15. Tens&parameters

16. Conventional tens

17. acupunturetens

18. Brief intense tens
 Rapid pain relief
 15-30minutes
 High frequency& more pulse width

19. Burstmode of conventional
tens

20.  Stimulation of appropriate nerve root(s)
 Stimulate the peripheral nerve (best if
proximal to the pain area)
 Stimulate motor point (innervated by the
same root level)
 Stimulate trigger point(s) or acupuncture
point(s)
 Stimulate the appropriate dermatome,
myotome or sclerotome

25. Introduce yourself to patient
Give assurance/confidence

26. Case sheet reading
 Go through the medical reports
 Find out diagnosis/general contra-
indications/previous physiotherapy
treatment

27. Checking general contraindications
 Hyper pyrexia
 Epilepsy
 Severe renal and cardiac problems
 Severe hypo/hypertension
 Cardiac pacemakers
 Infections
 Pregnant women
 Metal implants
 Mentally retarded/upset patients
 Malignancy
 Anterior aspect of neck/carotid sinus/eyes

28. Tray preparations
Skin resistance
lowering/testing tray
 Pillows
 Cotton
 Soap
 Towel
 Mackintosh
 Petroleum jelly
 Test tubes ( hot &cold)
 U-pin (sharp &blunt)
 Clips
 Bowl of water
 IR lamp
 Hot &cold packs
Treatment tray
 Pillows
 Towel
 Bed sheet
 Cotton
 Adhesive tapes
 Straps/goggles
 Salt/Powder
 Scissor/ Inch tape
 Paper
 Graph paper
 Pencil/scale/eraser
 Machine& accessories
 Sand bags/crepe bandages

29. Checking local contraindications
 Open wounds
 Scars
 Local skin infections
 Cuts
 Abrasions
 Eczema
 Local hemorrhagic spots
 Skin sensitivity (testing)

30. Apparatus preparation
 Check the apparatus& accessories like
electrodes, leads, cables, plugs, power
sockets, switches, controls, dials and
others

31. Apparatus checking
 Demonstration of the treatment
 Check the functioning of machine in
front of the patient
 Explanation of treatment

32. Positioning the patient
 Comfortable
 Relaxed
 appropriate

33. Skin resistance lowering
 Do skin resistance lowering
 Neatly &perfectly
 Use items required in an orderly manner

34. Selection of technique
 Use proper technique of application

35. Placement of electrodes
 Appropriate placement according to the
condition &patient
 Use adhesives &straps
 Apply gel evenly on electrode
 Maintain good contact with the skin
 No leads crossing each other
 Confirm connections &above all

36. Instructions & warnings
Instructions
 Don’t move
 Don’t sleep
 Don’t touch leads,
apparatus,
therapist and any
other metal near by
you
Warnings
 Inform more
heating/uncomforta
ble sensations
 Inform burning
sensation
immediately

37. Treatment
 Proper execution of treatment
 Appropriate intensity should be used
 Set duration of treatment acc. to
condition status
 Supervise the treatment through out the
session

38. Termination
 Put knobs to zero
 Remove electrodes
 Switch off the machine &mains
 Clean the area &inspect for adverse
reactions
 Manage if anything &give instruction
regarding next coming
 Winding up procedure

39. Recording
Accurate record of all parameters of
treatment including area treated ,
technique, dosage and the outcomes

40. CONTRAINDICATIONS
 Patients who do not comprehend the physiotherapist’s instructions or
who are unable to co-operate
 • It has been widely cited that application of the electrodes over the
trunk, abdomen or pelvis during pregnancy is contraindicated BUT a
recent review suggests that although not an ideal (first line) treatment
option, application of TENS around the trunk during pregnancy can be
safely applied, and no detrimental effects have been reported in the
literature (see www.electrotherapy,org for publication details)
 • TENS during labour for pain relief is both safe and effective
 • Patients with a Pacemaker should not be routinely treated with TENS
though under carefully controlled conditions it can be safely applied. It
is suggested that routine application of TENS for a patient with a
pacemaker or any other implanted electronic device should be
considered a contraindication.
 • Patients who have an allergic response to the electrodes, gel or tape
 • Electrode placement over dermatological lesions e.g. dermatitis,
eczema
 • Application over the anterior aspect of the neck or carotid sinus

41. PRECAUTIONS
 If there is abnormal skin sensation, the electrodes should
preferably be positioned elsewhere to ensure effective
stimulation
 • Electrodes should not be placed over the eyes
 • Patients who have epilepsy should be treated at the
discretion of the therapist in consultation with the
appropriate medical practitioner as there have been
anecdotal reports of adverse outcomes, most especially
(but not exclusively) associated with treatments to the
neck and upper thoracic areas
 • Avoid active epiphyseal regions in children (though there
is no direct evidence of adverse effect)
 • The use of abdominal electrodes during labour may
interfere with foetal monitoring equipment and is therefore
best avoided