Stimulation of sensory nerves:
- ES: Interferential and portable sensory TENS
- Current classification: of electrical stimulation
- Low frequency currents = 1000Hz or less (Portable TENS)
- Medium frequency current (Interferential) = 2000- 10,000 Hz
- High Frequency current = Megahertz
Interference current (IFT)
Two different medium frequency (cross over on each other) currents superimposed in the tissues at the same time
* Currents “interfere” with each other and a new
current results (beat or treatment frequency)
Physiological action
▪ Descending exogenous opioids via
Stimulation of sensory nerves:
▪ A-beta nerve fibres
o touch and pressure receptors
▪ A-delta fibres
o pain receptors
▪ Chronic pain guidelines
▪ Activates the Pain-Gate Mechanism:
▪ Alters neurotransmitter content
o effects on neuropathic pain
▪ Acute pain guidelines
Therapeutic uses of electrical stimulation
- CLBP
- Swelling
- Pain reduction and management
- Chronic pain (TENS)
Therapeutic application
* Acute pain settings (pain gate)
- Frequency: 80-150Mhz or 8—100 MHz
- Setup: Quadripolar set up or bipolar set up
- Intensity: mild sensation
- Time: 10-15 minutes
Therapeutic application
Chronic pain settings (endogenous opioids)
- Frequency: 0-25 Hz
- Set up: Quadripolar
- Intensity: strong sensation
- Time- 30-45 minutes +
TENS
Trancutaneous Electrical Nerve
Stimulation
TENS Therapeutic application
- Bipolar Application (low frequency)
- Over area of pain (different from IF)
- Dermatomal distribution
- Size choice dependent on site/area of
pain - Smaller the electrode = more
concentrated current - Dosage: 40-150Hz
- Time: 30-60minutes 1-2 x daily
- Watch for skin irritation
IFT vs TENS
IFT-
* Penetrates deeper into tissues
* Covers larger surface area
TENS-
* Smaller and more portable
* Cheaper- more widely available
Therapeutic uses of TENS
- Acute pain management
- Chronic pain management
- Labour pain (over sacrum and L/sp)
what is Ultrasound
Acoustic vibrations propagated in the form of longitudinal compression waves at frequencies too high to be detected by the human ear
Application requirements of tens
- Transducer head needs to be perpendicular to
surface - Transducer head needs to be in constant
motion - Avoid superficial bony areas- risk of burn
- Use sufficient coupling agent- gel, silicone sheet, water
Thermal CUS effects include the following
- Increased tissue temperature
- Hyperdynamic tissue metabolism
- Increased local blood flow
- Increased extensibility of collagen fibers
- Reduced viscosity of fluid elements in the tissue
Non- thermal mechanisms include the following:
- Ultrasonic cavitation- increase cell exchange across cell membranes
- Gas body activation
- Mechanical stress or frequency resonance non thermal processes
ultrasound Therapeutic Uses
- Facilitate soft tissue healing
- Facilitate bone healing (first 2/52 post injury)
- Hasten resolution of inflammation
- Pain relief
- Increase flexibility (as an adjunct to STM, exs)
- Reduce muscle spasm
Therapeutic application of ultrasound
- Can be used at 1 or 3 MHz- use dosage table
- 3 MHz
- used for superficial structure or bony areas
- Absorbed 3 x faster
- Heats 3 x faster
- Reduce time by 1/3 of that for 1MHz
- 1 MHz
- Used for deeper structures
- Add 0.25W/cm² per cm of depth (to 6cm)
Laser effect is
photochemical not thermal.
Physiological action
- Light wavelength penetrates tissues and absorbed in mitochondria
- Thought to increase oxidation capacity
- Enhanced cell proliferation of fibroblasts and growth factor
- Enhances neovascularisation
- Increases collagen synthesis
- Latent neural block- dec nociception at periphery
Therapeutic uses of laser
- The site of injury to promote healing, remodeling and reduce inflammation.
- Lymph nodes to reduce edema and inflammation.
- Nerves to induce analgesia.
- Trigger points to reduce tenderness and relax contracted muscle fibers
Therapeutic application of laser
- Best penetrating wavelengths in the range of 760–850nm
- Suggested light density of 5mW/cm2 at 5cm deep
- Power - 1Watt and surface density is 5W/cm2
- Treatment times per point are in the range of 30 seconds to 1 minute.
- 1-15 points depending on area to be treated
NICE guidelines- for electrotherapist
Do not offer ultrasound for managing low back pain with or without sciatica.
Do not offer any of the following electrotherapy treatments to people with osteoarthritis because there is insufficient evidence of benefit
Warnings for EPA
You are about to receive an ultrasound/ electrical treatment. All you should feel is a mild even warmth (heat/ C/US/ laser treatments) or mild even tingling sensation (IFT/TENS). If you feel anything other than this, or the sensation concentrating in one area please let me know immediately as you may be at risk of a skin burn or other tissue damage. Please do not move or touch the equipment during the treatment. Do you understand this warning? Do you have any questions? Are you happy to proceed?”
Contraindications and precautions for EPA
- Pregnancy
- Circulatory insufficiency (varicose veins; DVTs)- US
- Haemorrhagic conditions- US, laser, IFT/TENS
- Inability to communicate –All EPA
- Inability to detect heat- US
- Infective disorders
