ELECTRICAL CURRENT FOR PAIN CONTROL

ELECTRICAL CURRENT FOR PAIN CONTROL

2 Pain modulation ES for pain modulation (TENS) Parameter for ES for pain modulation

Pain modulation 3 Gate control theory of pain modulation Pain perception nociceptor : A-delta fiber, C fiber Non-nociceptor (A-beta fiber) : SC에서 brain으로의통증전달을억제 치료적전기자극은 A-beta nerve를선택적으로활성화시킴. How to activate A-beta nerve by ES? Pulse duration 50~80 μs (comfortable), pulse frequency 100~150 pps conventional or high-rate TENS

TENS for pain modulation 4 Conventional or high-rate TENS Low- rate or acupuncture-like TENS Burst mode TENS Electroacupuncture interferential current for pain control

Conventional or high-rate TENS 5 Pain modulation Gating에의한 Conventional TENS의 primary pain modulating effect는단지자극이적용될때만지속되기때문에환자가 pain이있어야하며, 필요하다면 24 시간까지적용할수있다. Pain-spasm-pain cycle를방해하므로자극이끝난후에도 pain reduction 효과있음 Endogenous opioids (Endorphins, enkephalins) 의 production/release를자극함으로써 pain control - descending inhibitory pathway [nonopioid(serotonin) system] 의활성 Recommended parameter Table 8-2 short pulse duration, high rate

Low- rate or acupuncture-like TENS 6 Repetitive stimulation of motor or nociceptive A-delta nerves m. contraction or brief sharp pain to stimulate endogenous opioids production and release Parameter (Table 8-2) - longer pulse duration and higher current amplitude than conventional TENS - lower frequency of 2 to 10 pps to minimize the risk of muscle soreness - pain control for 4~ 5 hours after a 20~30 minute treatment. Why? -treatment time이45분이상적용되어서는안된다. Why?

Burst mode TENS 7 low-rate TENS와 same mechanism. But. more effective Parameter : stimulate in burst or packages, composed of a number of pulses each

Electroacupuncture 8 TENS over acupuncture point -mechanism: 몸에서 acupuncture point를연결하는 acupuncture meridian을따라 energy flow를자극 - special training and license 필요

Interferential current 9 대부분의 TENS 은 pulsed biphasic current 사용 But interferential current 또한 pain control 가능 - to reduce pain and swelling - to increase ROM after knee surgery - to relieve pain related to chronic inflammation condition ex. OA, psoriatic arthritis

Contraindication and precaution for the use of electrical current

Contraindication for the use of electrical currents 11 Demand pacemaker or unstable arrhythmias Over the carotid sinus Venous or arterial thrombophlebitis Pelvis, abdomen, trunk, and low back area during pregnancy

Precautions for the use of electrical currents 12 Cardiac disease Impairment mentation or impaired sensation Malignant tumor Skin irritation or open wounds Iontoporesis after another physical agent

Adverse effects of electrical current 13 Careful evaluation으로 adverse effect 최소화 Burn at DC and AC Skin irritation or inflammation Pain

14 Application technique Patient positioning Electrode type Electrode placement

Patient positioning Area to be treated, goal of treatment, the device used 에따라환자자세결정 ES for muscle strengthening midline end of the available ROM Positioning strap, cuff weight 활용하여고정

Electrode type 16 Electrode most commonly used today Self-adhesive gel coating that serves as the conduction medium disposable and flexible gel : decrease resistance between the electrode and the skin Gel coating start to dry out uneven current density burn Carbon rubber electrode more long-lasting electrode, not self-adhesive Should be cleaned with warm, soapy water and not alcohol Current density 와 electrode size 는반비례 larger electrode : more comfortable than smaller ones cannot target small area

Electrode placement 17 Electrode must lie smoothly against the skin without wrinkles or gap self adhesive electrode : maintain good contact other type : flexible bandage 필요, Should not be placed directly over bony prominence distance or spacing between electrodes Document electrode placement using diagram

18 General instruction for ES

19 Figure 08-23. Treatment of upper back and neck pain with electrical stimulation.

20 Figure 08-24. A, Electrical stimulation to increase hamstring strength

21 Figure 08-24. B, Electrical stimulation to increase quadriceps strength.

22 General stimulations for ES

23 General term

25 Waveform

26 Alternating current Continuous bidirectional flow of charged particle equal ion flow in each direction, no pulse charge Frequency, cycle duration Relationship between frequency and cycle duration Frequency, cycle duration 1000~10,000 Hz

Medium frequency 27 AC with a frequency between 1000 and 10,000 Hz 2500 ~ 5000 Hz for clinical unit 2개의다른 medium frequency AC 의의해생성된 interferential current의형태로주로사용

Continuous current 28 Continuous flow of charged particles without interruption of break Continuous current Direct current(dc) : one direction Alternating current (AC) : two direction

29 Interferential current interferential current between two crossed pairs of electrodes ( 4 electrode) An alternating current with a frequency of 5000 Hz interfering with an alternating current with a frequency of 5100 Hz to produce an interferential current with a beat frequency of 100 Hz.

Interferential current 30 More comfortable than other waveform, Why? Low amplitude current on skin More total current than pulsed wave form Larger area than other waveform 많은 Animal study 에서 Inflammation 과 ischemia 와관련된 pain 을감소시킨다고하였으나, 특별하게다른효과없다고나타남.

31 Premodurated current AC with medium frequency Same form as an interferential current But single circuit and only 2 electrode No advantage of interferential current (lower current amplitude, large area)

Pulsed current(pulsatile current) 32 An interrupted flow of charged particle Type Monophasic pulsed current tissue healing and acute edema management application Commonly used High voltage pulsed current(hvpc) (= pulsed galvanic current) A, Monophasic; B, biphasic pulsed currents.

Pulsed current 33 Biphasic pulsed current Symmetrical : Asymmetrical : balanced, unbalanced Symmetrical, balanced asymmetrical biphasic current net chare of zero Often little difference between symmetrical and asymmetrical BPC Symmetrical : more comfortable for large muscle group Asymmetrical : for small muscle group A, Symmetrical; B, balanced asymmetrical; C, unbalanced asymmetrical biphasic pulsed currents.

Russian protocol 34 Waveform with specific parameter intended for quadriceps muscle strengthening Median frequency AC with 2500 Hz delivered in 50 bursts/second (= medium frequency burst AC)

35 Time-dependent parameter Frequency Interphase interval(intrapulse interval) Interpulse interval On:off time Phase duration Pulse duration Ramp up/ramp down Rise time/decay time Wave length

Frequency 36 Number of cycles or pulsed per second Measurement unit Hertz(Hz) for cycle Pulse per second(pps) for pulse Monophasic pulsed current with frequencies of 3 pps and 9 pps.

Interval 37 Interphase interval (intrapulse interval) Interpulse interval The time between phases of a pulse The time between pulse Interphase interval for a biphasic pulsed current

On: off time 38 On time: time during which a train of pulses occurs off time: time between trains of pulses when no current flows Usually only used when ES is used to muscle contraction On time, off time One time: muscle contraction off time : muscle relaxation, needed to reduce muscle fatigue during stimulation session Sequential on and off time to mimic the voluntary contraction and relaxation phases of normal physiological exercise On : off ratio 10sec on : 50 sec off 1:5 on off ratio On:off times for a biphasic current

Duration 39 Phase duration Pulse duration Duration of one phase of a pulse μs, ms Time from the beginning of the first phase of a pulse to the end of the last phase of a pulse μs

Time 40 Ramp up / ramp down time Rise time/decay time During the on time During any one phase

Wavelength 41 The duration of 1 cycles of AC The wavelength of AC is similar to the pulse duration of pulsed current

42 Other ES parameter Amplitude (intensity) Amplitude modulation Burst mode Frequency modulation Modulation Phase duration or pulse duration modulation Scan Sweep

Amplitude (intensity) The magnitude of current or voltage

44 Modulation

Burst mode 45 A current composed of series pulsed delivered in groups known as burst

Modulation 46 Used to limit neural adaptation to an electrical current Type Amplitude modulation Frequency modulation Phase duration /pulse duration modulation Scan : amplitude modulation of an interferential current Sweep: frequency modulation of an interferential current

47 Nerve and electrical current Absolute refractory period Accommodation Action potential Adaptation Chronaxie Depolarization Myelin Node of Ranvier Propagation Relative refractory current

48 Unn Figure 08-01. Unn. Fig. 8-1.

49 Medium frequency Continuous current Direct current Alternating current Interferential premodulated current Russian protocole