electrical stimulation (1)
DESCRIPTION
PTTRANSCRIPT
Electrical Stimulation
All Kinds of Choices
Stimulating Units
• Fall into one of two categories:
• Low Volt (Less than 100V)– TENS (9V battery)
• High Volt (Greater than 100V)– Pretty much everything else
Carrier Frequencies
• Low-frequency currents– 1000 pps or less (Monophasic, Biphasic)
• Medium-frequency currents– 1000 pps – 100,000 pps (IFC, Russian)
• High-frequency currents– 100,000 pps and higher (Diathermies)
Waveforms
• Monophasic
• Biphasic
• Interferential
• Pre-modulated Interferential
• Russian
• TENS
• Microcurrent
Monophasic
•Unidirectional flow of electrons
•Negative / Positive polarity
•“Twin Peaked Monophasic”
Peak Current
Pulse Duration
75 µs
Biphasic
•Positive and Negative Phases
•Symmetrical / Asymmetrical
Interferential Current
•Two channels at separate frequencies•Less skin resistance•Quadripolar Electrode Configuration
5,000 Hz
5,100 Hz
Interferential
Channel 1
Channel 2
Beat Frequency: 100 Hz
Interference Current
Ch 1
Ch 2
Ch 2
Ch 1
Pre-modulated IFC
•Bipolar electrode configuration
•“Mixing” of currents occurs inside the machine
•Less penetration than IFC
Russian
•Classical Russian Stim involves 2500 Hz carrier frequency w/ beat frequency from 1 – 100 Hz•Thought to allow more current to reach motor nerve at lower intensities•Results have never been duplicated
TENS
•“Transcutaneous Electrical Nerve Stimulation”•Primarily used for pain reduction
–Gate Control
–Endogenous-opiate release
Microcurrent
•Subsensory or very low sensory level•Very small current amperage / Very high pulse duration•Very theoretical / not much supporting research•Attempts to re-establish body’s natural electrical balance by allowing ATP supply to increase metabolic energy for healing to occur
Levels of Electrical Stimulation
• Subsensory• Sensory
– Pain Relief – Edema Control
• Motor– Pain Relief– Edema Control– Muscle Re-education
• Noxious
Subsensory
• Microcurrent
• Unable to stimulate nerve or muscle
• Variety of recommended parameters
• Generally consists of 2 – 10 minute Tx’s
Parameters
• 1st Treatment– Frequency: 30 Hz
– Intensity: 600 µA
• 2nd Treatment– Frequency: .3 Hz
– Intensity : 60 µA
• Lynn Wallace
• Pain Mode– Frequency: 30 Hz
– Intensity: 80-100 µA
• Healing Mode– Frequency: .3 Hz
– Intensity: 20-40 µA
Sensory Level Pain Relief
• Stimulation at or above sensory threshold but below motor level
• Stimulation of Aβ fibers – Gate Control Theory
• Frequency: 50 – 150 Hz• Phase Duration: Less than 100 µs
• Intensity: Comfortably strong
Sensory Level Edema Control
• Done immediately following injury to limit formation of edema
• Not widely researched but a few theories– Decreased capillary pressure and permeability
which keeps plasma and proteins from entering extracellular tissues
– Vascular spasm preventing leaking from vessels
• Waveform: Monophasic
• Frequency: 120 pps
• Phase Duration: As high as possible
• Intensity: Comfortably strong
• Monopolar electrode configuration– Negative electrodes over injured area
Motor Level Pain Control
• Best used with subacute / chronic pain
• Endogenous opiate release– Longer duration of pain relief
• Also good for trigger points
• Frequency: Low; 2-4 pps
• Phase Duration: Wide; 200-300 µs
• Intensity: Strong, twitch contractions
Motor Level Edema Control
• Muscular contractions encourage venous and lymphatic “milking” fluids from the area
• Electrodes arranged to follow primary vein exiting swollen area
• May be continuous or on / off time
• Continuous
• Frequency: 1 – 2pps(or as low as possible)
• Phase Duration:– 200 – 400 µs
• Intensity:– Strong, twitch contractions
• On / Off time
• Frequency: 25 – 50pps
• Phase Duration:– 200 – 400 µs
• Intensity:– Strong, tonic contractinons
• Duty Cycle: 50%– 5 on / 5 off
– 10 on / 10 off
Muscle Re-education
• Neuromuscular Electrical Stimulation (NMES)• Muscle re-education, reduction of spasticity, delay
of atrophy, muscle strengthening• Stronger type of current, not as comfortable as
other forms of ES• Not as effective as voluntary contractions
• Frequency: 25 – 50 pps
• Phase Duration: 200 – 400 µs
• Intensity: Strong tonic contractions
NMES Principles
• Duty Cycle– 1:5 (10 on / 50 off) Strength– 1:2 (10 on / 20 off) Endurance– 1:1 (10 on / 10 off) Fatigue
• Ramp Times– Fast ramp on: .5 – 1 sec Power– Long ramp on: 1 – 2 sec Strength– Long ramp off: 3 – 5 sec Eccentrics
Noxious Stimuli
• Causing pain to relieve pain
• Stimulation of Aδ and C fibers
• Electrode placement is variable
• Generally used as a last resort
• Longer lasting pain relief
• Frequency: 1-5 pps or 80-100 pps
• Phase Duration: 1 ms or higher
• Intensity: Noxious (painful)
Conclusion
Lots of machines, lots of choices.
Everybody is different, so don’t be afraid to try different things if things aren’t going as planned.