Interrupted Direct Current in Physiotherapy
A term for constant direct current, named after Luigi Galvani from Bologna in 1889, used in therapy since the end of the 19th century after the batteries for it constructed successfully. Today we get galvanic current from the alternating current of 50 pulse per second frequency and 220 voltage. Devices for this transformation several electronic tubes through which the alternating current flows through in a single direction (from a cathode to anode). This gives us pulsating full-wave direct current which turns into constant after the filtering, used in therapy
Galvanic current used via two electrodes, one positive (+, usually red), and the other negative (-, usually black).
An interrupted direct current also called long duration current having more than 1 ms up to 300 ms or 600 ms. But the commonly used duration 100 ms duration requires a frequency of 30 pulses/ min. If the duration increases the frequency may reduce. The interval between the impulses should never of shorter duration than the impulses themselves.
HOW DO WE USE GALVANIC CURRENT?
In practical therapy, galvanic current used in several ways:
Dry galvanization through moist electrodes
Special forms in certain body parts
1. DRY GALVANIZATION
Dry galvanization can apply in several ways:
Transverse or transregional galvanization
– set transversely on a certain body part. This way equal flow of tissue between the electrodes is achieved.
– electrodes set on different extremity heights (on the endings) – e.g.one electrode on the shoulder, and the other on the palm of the hand. This way we achieve surface flow. Longitudinal galvanization can descend or ascend.
– applied via two electrodes, one active (mobile, applied in painful spots), the other inactive and considerably bigger.
If the patient experiencing trigeminal neuralgia, galvanization applied through a special semi-mask (Bergonzi) electrode. Mask-shaped cathodic electrode fixated on the neuralgic side, while the inactive electrode placed on the sternum or between the shoulder blades.
HOW TO PLACE ELECTRODES?
Electrodes never placed directly on the skin – they need to have hydrophilic cloth folded over them. Most frequently we use sponges moistened with water. Prepared electrodes usually fixated with elastic bandages or sandbags.
SCALING AND DURATION OF THE TREATMENT
When scaling the galvanic current we need to pay attention to two things. First the patient’s subjective feeling – feelings of tingling to present, but not pain or burning. Galvanic current to gradually applied with constant assessment of the patient’s feeling.
The second parameter current density on the electrode surface ( mA/cm2 ). It needs to within the limitations of the physiological sensitivity (0.1 to 0.5 mA/cm2). One application lasts between 10 and 20 minutes.
The intensity and duration of impulses in galvanic current adequate so that it can cause a sluggish worm like a contraction.
When current applied it produces sensory stimulation resulting in the feeling stabbing or burning sensation.
It increases blood circulation causing erythema (redness) of the skin.
Stimulation of motor nerve with such current produces contraction of the muscle supplied by that nerve.
Galvanic current affects neural endings responsible for the transfer of pain so that the pain diminished or removed completely. Cathodes enhance stimulativeness and conduciveness of the nerves, while anodes diminish them.
Vasodilation (expansion of blood vessels) happens under the influence of the galvanic current, causing hyperemia, excessive accumulation of blood in a part of the body. The skin under the electrode becomes warmer, redder, and moister, in a period of up to 30 minutes.
confusion over the therapeutic use of electrical stimulation for denervated muscles for the last many years. The purpose of such current to maintain the muscles in an as healthy state as possible to prevent the complication by electrically artificial contraction. Skeletal muscles have a greater power of regeneration. When the muscles are denervated the following changes will occur.
Loss of voluntary contraction and reflex activities
Atrophy: Resulting in fibrosis
Fibrillization: Spontaneous contraction
If some of the motor units (motor end plate + motor nerve + muscle fibers) are intact galvanic current is the choice of treatment.
Interrupted direct current is still recommended for the treatment of Axonotmesis and Neurotmesis nerve repair is to be taken
WHEN TO APPLY GALVANIC CURRENT?
rheumatic diseases, except in their active or acute phase
paresis and paralysis – galvanic current is here used as the introduction for electrostimulation (galvanic current diminished skin resistance through hyperemia, so we can achieve a strong muscle contraction with little stimulation
blood vessel diseases and circulation disorders
Cardiac pacemakers and Arrhythmias
Thrombosis and thrombophlebitis (inflammation of the wall of a vein)
Early tendon transfer and repair
Pregnancy: On pelvic, low back and abdomen
Child with mental disturbance
Infected wound and skin lesion