Medium Frequency Current.ppt

Introduction, principles, treatment parameters, gate control theory

1. Medium Frequency Current
MEDICAL PHYSICS
Physical Therapist
Dr. Naveed Ahmad
DPT(RIU),MS-OMPT*(RIU)

2. INTRODUCTION
INTERFERENTIAL CURRENT(IFC)
IFC has been reported to have the
advantage of reducing the skin resistance,
and thus the discomfort normally while still
producing low-frequency effects within the
tissues.

3. PHYSICAL PRINCIPLES OF
INTERFERENTIAL CURRENT
IFC is produced by mixing two medium-
frequency currents that are slightly out of
phase, either by applying them so that they
‘interfere’ within tissues
alternatively by mixing them within the
stimulator prior to application.

4. PHYSICAL PRINCIPLES OF
INTERFERENTIAL CURRENT
One current is normally of fixed frequency,
for example at 4000 Hz, and the other
current is adjustable, for example between
4000 and 4200 Hz.
Two currents summate or cancel each other
out in a predictable manner, producing the
resultant amplitude-modulated ‘interferential
current’.

5. PHYSICAL PRINCIPLES OF
INTERFERENTIAL CURRENT
The frequency of the resultant current will be
equal to the mean of the two original currents,
and will vary in amplitude at a frequency
equal to the difference between these two
currents.
This later frequency is known as the
‘amplitude-modulated frequency’ (AMF) or
‘beat frequency’.

6. PHYSICAL PRINCIPLES OF
INTERFERENTIAL CURRENT

7. TREATMENT PARAMETERS
Current Intensity
‘Strong but comfortable’ stimulation
Intensity should be slowly tuned up
Treatment duration
10-20 minutes

8. THEORETICAL PAIN RELIFE
MECHANISMS WITH IFC
The pain gate theory
Gate -located in the dorsal horn of the spinal
cord
Increased circulation
Descending pain suppression
Physiological block of nerve conduction

10. Evidence for theoretical analgesic
mechanisms with IC

11. Adverse effects
Burns
Increased pain
faintness
headache
Neurological effects

12. Adverse effects
Patients where disturbance of a thrombus,
spread of infection or cancerous cell, or
haemorrhage might result
Pacemakers
The abdomen during pregnancy
The chest wall in patients with cardiac
problems.

13. PHYSIOLOGICAL OBJECTIVES
Pain relief both acute and chronic
Reduction of edema
re-education and strengthening of muscle.
Stimulation and improvement of circulation
General facilitation of healing

14. THANKS