DIDYNAMIC CURRENT Miss Hira Jabeen ANMC

OBJECTIVES Introduction Basic current (MF, DF ) Derivative of basic current Brief description of Dia dynamic and basic currents Characteristics of diadynamic current, Techniques of application & treatment, frequency of treatment. Clinical indication

Definition “Didynamic current is a monophasic sinusoidal current being rectified main type current.” It can be semi-wave and full-wave 50-100 Hz frequency Pulse duration of 10 msec Providing 100 stimuli / sec.

Types of Didynamic Current Two basic forms: Monophasic fixed (MF) Diaphasic fixed (DF)

MONOPHASIC FIXED Half-wave rectified sinusoidal current, with a frequency of 50 Hz Series of 10 ms half sine-shaped pulses 10ms pulse width

Diaphasic Fixed Full wave rectified sinusoidal current Continuous series of 10ms sinusoidal pulses Freq = 100 Hz

Derivatives of Basic Current CP (courtes periods )Module: If two currents form MF & DF applied alternatively for 1 sec each

LP ( longus periodes) Module If two MF currents are applied so that one series of pulses occupies the pulse interval of the other and one is of constant intensity while other is surged The length of each surge and surge interval varies with different sources Usually of 5 or 6 sec

Physiological Effects Stimulation of sensory nerve Stimulation of motor nerve Muscle contraction Chemical changes due to unidirectional flow of current

Therapeutic effects Pain relief Dec inflammation and swelling Muscle re-education and strengthening Inc local circulation Facilitation of tissue healing

1. Pain relief Pain gate mechanism Pain suppression due to neurologically stimulated endorphins & enkaphlins Removal of irritants by local inc circulation Placebo effect Vibration stimulation leads to central masking of pain sensation.

2. Dec inflammation and swelling Inc pumping action Inc local circulation Changes in cell membrane permeability CP and LP currents stimulate increase blood flow to the muscle and reduce edema

3.Muscle re-education and strengthening Didynamic current stimulates the muscle fibers, causing muscle contraction Rule With weights

4.Inc local circulation Altered autonomic activity Dec sympathetic tone Vasodilation Release of histamine due to unidirectional effects

5.Facilitation of tissue healing Local circulatory & polar effects Inc cell activity

Individualized Current effects DF ( Fixed Di-phase): It is used for the initial treatment and before application of other currents. The patient feels a prickling sensation, which subsides after a short time. MF( Fixed Mono Phase): The patient feels a strong vibration for longer time than the sensation of DF. It is used for treatment of pain without muscle spasm.

CP( short periods): In DF phase, there are fine tremors in MF phase (strong and constant vibration). There are rhythmic contractions, being used for treatment of traumatic pain. LP(Long Periods): It has a long-lasting analgesic effect. It is used with combination of CP in treatment of neuralgia.

Application of electrodes Carbon rubber or metal with pads Two equal sized on either side to be treated Small electrode over trigger point and large placed more proximally

Sites Trigger points Painful area Nerve root (Paravertebral region) Nerve trunk Vasotropic ( tending to act on blood vessels)

Dosage: Intensity: It should be increased gradually until definite vibration or prickling sensation occurs. Not tetanic Duration: Not more than 12 minutes; each type for 3 minutes. Frequency : Daily or every other day for 12 sessions

Indications Didynamic stimulation causes relief of pain and edema in the following conditions: 1. Soft tissue injury (sprains, strain, contusion and epicondylitis). 2. Joint disorders (post-immobilization and arthritis).

3. Circulatory disorders (Raynaud's disease and migraine). 4. Peripheral nerve disorders (neuralgia and sciatic neuritis).

Contraindications Open skin: The current tends to concentrate at this point; small broken areas can be insulated by Vaseline. Bony areas: It may produce a burn. Loss of sensation: It can produce a burn. Skin lesions: Eczema or fungi can be irritated and made worse.

Infections : It may cause spreading of infection. Thrombosis. •Cardiac pace makers •Superficial metal Tumours Pregnancy

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