IFT Flashcards
PHYSIO AIM VS PHYSICS AIM
Stimulate sensory nerves to facilitate the pain
inhibitory systems for pain relief and reduce
swelling.
PHYSC: IFT interfere two alternating currents inside
human body
PHYSCICS
‣ IFT generates two out-of-phase mediumfrequency
currents which interfere with each
other inside human body
‣ Skin, tissue and muscle have different electric
impedance.
‣ Medium frequency current can pass through
skin with less impedance.
‣ Interference current
‣ has low beat/modulation frequency which
acts like pulsed current
‣ however needs HIGH intensity (amplitude) to
stimulate sensory nerves
‣ High intensity (amplitude) means more nerves
are recruited for stronger stimulation
MEDIUM FREUQENCY, LOW BEAT FREQUENCY, HIGH INTENSITY - INCS. NERVE STIMULATION
PHYSIOLOGICAL EFFECTS
PHYSIOLOGICAL EFFECTS
‣ IFT targets different pain inhibitory systems
depending on the settings applied
1. Pain Gating through stimulation of large
diameter sensory nerves Aβ
2. Endogenous Analgesia through
stimulation of small diameter afferent
nerves Aδ or C
‣ Sweep used to reduce swelling (large) and
avoid accommodation
‣ Thought to penetrate deeper and cover a
larger area than TENS
‣ Secondary aim is motor stimulation
‣ Depolarises motor nerves instead of sensory
nerves to generate a contraction of the
muscle fibres *limited use
Interference of currents:
Currents that co-exist can interact and hence constructively and destructively. Result will be a current with different amplitude and frequency
Beat/Modulation frequency:
Interference of two currents with different frequency (but close to
each other) cause a modulating current with a
low modulation frequency. This frequency is
equal to frequency difference of original
currents.
CONTRAINDICATIONS
Vicinity of uterus in pregnancy
Over inbuilt stimulator (eg. Pacemaker)
PRECAUTIONS
Circulatory Insufficiency Risk of dissemination Exacerbation of existing conditions Unable to communicate Sensory loss
Settings/Dosage
PG: 10-20 mins intensity when comfortable sensory FREQUENCY Gating: 0-199Hz *sweep if swelling Endogenous: 1-10, 1-20 or 1-5 Hz
MMF
Modulated Medium Frequency Current - 2pole
warning
When having electrical stimulation you
should feel (for Pain Gating) a mild tingling (for
Endogenous Analgesia) a strong tingling which may be
uncomfortable but not painful.
Please do not move or touch any of the equipment during treatment.
Safety points
- Cross two channels diagonally - Ensures the currents interfere inside human body.
- No jewellery - metal is conductor and change electric field and current and can result in an electric shock
- Check skin for any irritation
under electrodes
Avoid any tissue damage secondary to increased kinetic energy
which can cause an electrical burn
Use electrodes of the same size
(bipolar application)
Using different sizes of electrodes causes change in current density
inside human body that concentrate the energy over a smaller area.
remember
CHECK ON SELF FIRST !!
TURN OUTPUT TO ZERO, DISCONNECT THEN TURN MACHINE OFF
Why are low amplitude currents used in IFT?
By starting with lower amplitude current, the sum of the
combined currents will remain within a safe level for
human tissue.
Why do medium frequency currents penetrate deeper?
The opposition to the flow of alternating currents
depends on its frequency. A medium-frequency current
experiences less impedance
What are the different pain inhibitory systems which can
be targeted with IFT?
Large afferent fibre stimulation (via Aβ fibres) activating
pain gating mechanisms at spinal cord level (dorsal
horn).
Endogenous analgesia from stimulation of Aδ or C
fibres activating endorphin/encephalin release in the
spinal cord or from higher centres in the brain.
