This document discusses various forms of electrotherapy used to treat musculoskeletal disorders. It describes galvanic current, diadynamic current, interferential therapy, and TENS. Galvanic current directly stimulates muscle without activating nerves. Diadynamic current comes in various forms that can stimulate muscles or affect the autonomic nervous system. Interferential therapy uses two medium frequency currents to produce a low frequency effect for pain relief and muscle stimulation. TENS is a form of electrical stimulation that decreases pain by activating sensory nerves via surface electrodes.

2. Def.: use of electricity in the ttt of musculoskeletal disorders.
The choice of adequate modality is according to the structure to be
treated, the pt. tolerance and the absence of contraindications.
We can use more than one modality
to treat the same condition ( multi
modal ttt)

3. Electrotherapeutic modalities:
DC
valve
Interrup
ted low
freq.
DC
Surged
current
Diadynamic current
 MF (monophasic)
 DF (diphasic)
 CP ( courte “short” period)
 LP ( long period)
Medium freq.
current
SWD IFC TENS
High freq.
current
Deep
heating
Low freq. current
ULTRASONIC
THERAPY ULTRAVIOLET LASER
LIGHT WAVES LIGHT WAVES US WAVES
Electrical stimulation→ nerves + ms.
Thermal,
Mechanical,
Chemical and
biological effects
Thermal,
Physical ,
Chemical and
biological effects
*The most common form of electrotherapy is pulsed or interrupted AC.
Erythema production,
Tanning, Epidermal
hyperplasia, Vitamin
D synthesis
TNS

4. TNS
(Transcutaneous neuromuscular stimulators)

5. DC
valve
Interrupted low
freq. current
TNS
(Transcutaneous neuromuscular stimulators)
Diadynamic current
 MF (monophasic)
 DF (diphasic)
 CP ( courte “short” period)
 LP ( long period)
IFC TENS
Low freq. current
Medium freq.
current
Electrical stimulation→ nerves + ms.
Surged
current
Denervated Ms.

6. Galvanic (direct)
current

7. Galvanic current
It is a direct Current used to stimulate muscle directly, without
activation of the peripheral nerve “ surged current”.
- Direct muscle stimulation requires pulse of long durations of at least
100 milliseconds, and more often uses even longer durations.
appropriate electrical stimulation can cause a denervated muscle to
contract
•contraction of a denervated muscle may help limit edema and venous
stasis within the muscle, and therefore delay muscle fiber degeneration
and fibrosis
•recovery time following denervation appears to be shortened with
appropriate electrical stimulation

8. Rheobase: is the minimum DC necessary to
produce a contraction in Ms.
Chronoxia: is the time in which a current double
the rheobase produce a contraction. The
Chronoxia in normal Ms. differ from 1/8000 –
1/20000 a second. In denervated Ms. The
Chronoxia is increased 20 – 100 times the normal
amount from the tenth day onwards. Duration
Strength of Stimulus
Minimal time
Chronaxia
Utilization time
Rheobase
Threshold
Time
Current intensity
nerve
Threshold
Rapid rise
Effective
slow rise
Ineffective in innervated Ms.
but effective in denervated Ms.
Rate of rise of intensity
Too slow rise in stimulus strength→ nerve
accommodation occurs (i.e. rise in the threshold
of stimulation of the tissues) → no response of
the innervated ms. This propriety used to
selectively stimulate the denervated ms.
nerve accommodation
Ms.

9. Surged current(ramping):
gradual increase the charge applied to the tissue hence increase the
intensity of Ms. Contraction attained.
This achieved by gradual increase in the amplitude or the pulse width
of the pulse train. This allows for accommodation of the nervous
tissue to pulse delivery. It is postulated that slow rising pulses of long
duration selectively stimulate denervated Ms. As opposed to fast
rising pulses of short duration that stimulate innervated Ms.
Surged rectangular surged triangular sow tooth

10. • Galvanic current indications:
• Electro diagnostic
• ++ of paralyzed Ms. Of LMNL.
• Peripheral nerve injury.
• Bell’s palsy.
• Iontophoresis.
• Hysterical conditions.

11. Diadynamic current

12. Diadynamic current:
Def.: sinusoidal direct low frequency current (50-100 Hz).
Type of Diadynamic current:
1- monophasic (MF):50Hz impulse
& interruption 10m.sec.
Effect: muscles stimulation  ms. contraction.
2- Diphasic (DF): freq. 100HZ & non interruption.
Effect: affect autonomic nervous system
by lowering the sympa. Tone.
3-Short “courte” periodes current (CP): sudden
alternation between monophasic and diphasic>
Used for: long term pain relief.
4-Long periods current (LP): MF mixed with
a second modulated MF
Use: analgesic effect
pt. feels pleasant sensation than that produced by CP.
5- Rhythmic Syncope (RS): This consists of 1.1 second MF followed by 0.9 second rest phase.

13. Therapeutic effects and mechanism of action:
1- analgesic: may be due to blocking of a particular area of the reflex
(through nerve fibers).
DF  brief analgesic effect.
CP  long term pain relief
LP  reduce pain “with pleasant sensation”.
2- hyperemic ( anti-edema):
DF decrease sympathetic tone  V.D  increase blood supply 
increase metabolic rate in the tissues  rapid reabsorption of edema
 decrease swelling  rapid recovery.
3- muscles stimulator: MF is motor stimulator, also RS and modulated
MF (L.P) produce muscles contraction.

14. Treatment strategy:
- Current strength is gradually raised to the tolerance level (pt. remain comfortable)
- Duration : 2-12 min .. Not exceed 15min.
- Therapy : 6 application ( EOD or daily). Sever cases up to 3 time /day
- The interval between sessions should not > 48hs.
- Even if the pathological symp. Disappear afer 2-3 sessions add 2-3 sessions to stabilize
the effect.
- If after 6 sessions non improvement; interrupt for 1week and recontinue.
Indication:
• Sport inj.(rapid effect) Sprain, Contusions, Dislocation. ms. And joints pain.
• MSk problems & soft tissues inj.( OA – RA – back pain – neck pain … etc.)
• Neuralgia and neuritis.(trigeminal, brachial, sciatic, herpes zoster neuralgia…etc)
N.B.: Diadynamic c. can be used alone or with other modalities like ultrasound and
microwaves.

15. contraindications:
Acute infection
Various dermatological lesions.
Metal implantation.
Malignancies.

16. Interferential therapy

17. Interferential therapy:
 Def.: it is a form of electrotherapy in
which 2 medium freq. currents
are used to produce low freq. effect.
 Principle: skin impedance (resistance) is
More comfortable than low freq. and more tolerable.
inversely proportional to the freq. of the
current used. So the main problem associated
with low freq. is the very high skin resistance
which is the cause of pain during treatment.
Resistance decreases if 2 medium freq.
currents crossing the pt. tissue one of them is
kept at constant freq. of 4000 Hz and the
other change between 3900 – 4000 Hz.
So peak effect = diff. between the 2
= 100 Hz (low freq. current).
3900Hz 4000Hz
100Hz
The low freq. current effect is developed at
The point where the 2 currents cross
( low freq. effect).

18. physiological effect: and advantages
1- relief pain (80 – 100 Hz):
 local ↗ of the circulation.
pumping effect of the ms.  removal of waste productes.
autonomic effect on the autonomic nerve.
stimulation of large diameter nerve fibers which inhibit
transmission of small diameter nociceptive traffic
(by 80 – 100 Hz) “gate control”.
 stimulation of small fiber which will cause the release
of enkephalin and endorphin at spinal level ( by 15 Hz).
2- Motor stimulation:
ms. Contraction (1 – 100Hz )
o Turtches (<5 Hz)
o Partial tetanic (5 – 20 Hz)
o Tetanic ( 30 – 100 Hz)

19. Stimulation of both voluntary and smooth ms. (but faradic stimulation only voluntary ms.)
with little sensory stimulation  more comfortable.
contraction of deeply placed ms. E.g.:
• Lower abdominal ms.
• Pelvic floor ms. In stress incontinence.
• ms. of inner side of the thigh.
3 - Absorption of exudate ( 1 – 10 Hz)
• Rhythmic ms. Contraction (pump)
• and autonomic effect on the blood vessels
 absorption of exudate  ↘ swelling.
4 - ↗ healing (up to 100 Hz): ↗ tissue healing & resolution of acute and chro.
Inflammation.

20. Factors affecting physiological effect of I.F.C
I. Current intensity
• Low  sensory response (fine tingling), used in acute pain, swelling and ↗ circulation.
• Medium  strong tingling + ms. contraction. Used in ms. Srengthing & ms. Reeducation.
• High  painful stimulation(↗tingling + contraction + pain), used in chro. Pain.
II. Beat of frequency:
• 1 – 10 Hz  ↘ swelling.
• 5 – 20 Hz  motor stimulation.
• 80 – 100 Hz  pain relief.
III. Rhythmic or constant
IV. Accuracy of electrode positioning.

21. Indication of IFC:
o Reduce inflammation & oedema (by Increased local blood flow ).
o Muscle stimulation (ms. Reeducation and strengthing)
o Pain relief.
Contra-indications:
Acute inflammation or TB
Malignancy.
Metal implants.
Pace makers
Skin lesions.
Intolerance
Pregnancy, menses (excessive bleeding) for IFC of lower abdomen.
Over thrombo-phelibitis (release of thrombi)
Febrile conditions.

22. Dangers:
Bare electrode touches the skin.
Electrodes on the skin are too close allowing the short circuit.
Technique of application:
 Preparation of the pt.
ᴥ comfortable ᴥ skin soaks with saline ᴥ skin lesions is insulated with pet. Jelly.
 Preparation of the apparatus
ᴥ electrodes connected to terminal ᴥ pads soaked with saline
 Application of current:
Positioning the electrodes so that the crossing points of the 2 currents is over or within the lesion.
appropriate freq. to the indicated condition.
current intensity is adjusted until the pt. feels mild tingling sensation. after few minutes
accommodation may occurs and the intensity may be increased
for about 15 minutes.

23. T E N S

24. TENS transcutaneous electrical nerve stimulation
Def.: is the application of pulsed low freq. current of rectangular wave through
surface electrode on the skin surface over afferent nerve endings for stimulating the
sensory component of the peripheral nerves to decrease pain.
Physical characters:
o It is a sensory stimulator not ms. Contraction device
o It is either monophasic or biphasic
o It has different shapes: rectangular or spike
o The most effective shape is still unknown.
o It is formed of pulses which has 0.2m.sec ( as duration < 10m.sec stimulate
sensory only not motor fibers.
o Intensity 60 milli-ampears ( can be modified according to the propose response.
( as intensity from 30 – 150 milli-ampears stimulate sensory only not motor fibers.
o Freq.  low ( 10 – 100Hz)  conventional TENS.

25.  Mechanisme of TENS: ( physiological effect  just pain relief)
a) According to gate control theory, pain which is transmitted by
small unmylinated fiber my be inhibited by stimulating thick
mylinated fiber.
b) Electrical stimulation may ↗ release of endogenous morphine
like substances: which has analgesic properties and so that the
affect of TENS might be measurable by estimated of the level of
opiate like substances as enkephalins & endorphins.
c) It is suggested that it can ↗ pain threshold.
d) psychological (placebo) effect.
 Methods of application of TENS:
 Transcutaneous method:stimulation of the peripheral nerves by
application of the electrodes on the skin superficially.
 Percutaneous method: used as diagnostic to assess the possible
value of an implantable nervous system stimulator.
 Implantation method: applied by using a cuff electrodes of
various size which is placed around the affected peripheral nerve
usually proximal to the area of injury.

26. INDICATIONS of TENS:
o Acute pain:
• Musculoskeletal system:
Articular : arthritis
non articular: strain of ligament muscles sprain.
lumbar spondylosis.
• Sport injuries:
lig. Or ms. Sprain.
shoulder contusion.
• Neurological:
Trigeminal neuralgia. Brachialgia
sciatica post herpetic neuralgia
• 1st stage of labour.

27. INDICATIONS of TENS: …cont
o Chronic pain:
• As rheumatoid arthritis, osteoarthritis.
• LBP. Lumbar spondylosis.
• Neuropathy or myofacial pain.
o Post-operative pain:
• Including dental extraction, post-laminectomy or
abdominal injuries.
o Cardiopulmonary problems:
• ↗ pulmonary function test after thoracotomy.
• ↘ pain of frozen shoulder.

28.  Electrodes:
Made of carbon filled silicon. It require gel for
Application.
If allergy use another) certain called Karaya-electrode
“ skin friendly electrode”, or interrupt the period of
stimulation with period of rest.
In acute post operative incisional pain we use a
disposable pre-sterilized electrodes.
 Technic of stimulation:
The pt. should recognize the device and the
electrodes and the tingling sensation which can
be felt during the application and this sensation
must be strong and tolerable at the area
of stimulation.
The freq. of the device range from 10 – 150 Hz.
The electrodes are placed at the region of pain.

29.  Electrodes placement:
By direct application to the skin.
1) over painful area.
2) in case of nerve root irritation which produce
radiating pain; one electrode is placed over its
dermatomal distribution, the other electrode is
placed over the side of the affected spinal
segment root level.
3) In cases of nerve root without radiating
pain ;one electrode ipsilateral and the other contralateral.
4) If the pain is muscular or bony origin
the electrodes are placed over the
myotomal or the sclerotomal
distribution.
5) In peripheral nerve injuries or
peripheral neuropathy the stimulation is
at the site of the pain

30.  Electrodes placement: … cont
6) In neurological injuries the loss of sensation in
the painful area, contralateral stimulation can be
done.
7) In low back pain and cervical syndrome, bilateral
stimulation of the painful area or the ipsilateral is
effective.
8) If there is localized pain and no trigger point are
involved place one electrode on the painful area
and the other over the dermatomal distribution
either on the opposite side of the corresponding
level or distally according to the pain radiation.
9) During labour:
↗freq.  120 Hz.
proximal electrode over T8.
distal electrode over S1
2ed stage  anterior abdomen.

31. Duration and freq. of treatment:
• The session of the pt. is 30 – 60 min
about 2 – 4 times / day.
• The periods of ttt must not be less
than 30 days at least.
• Rarely pt. use the device 24hs but it
seems to be less effective.
Side effect of TENS:
o thalamic stimulation by TENS may
lead to vertigo, nausea, shortness of
breath or nystagmus.
o Allergy to gel of electrode.

32. CONTRAINDICATIONS of TENS:
• Over the carotid sinus.
• Corticosteroids are avoided because it suppress the
endogenous analgesic system.
• In case of unknown pathology. For feer of mistaking pain 
harm to the pt.
• Pt. with cardiac pacemaker as TENS may interfere with it
• Acute illness.
• Fever > 38 c
• Over pregnant uterus.
• In case of malignancies