Electric Currents Part 2 By B. Nelson

Clinical Applications of Electric Current Muscle contraction of innervated muscles Muscle contraction of denervated muscle Pain modulation Tissue healing Iontophoresis

Muscle contraction Electric Currents used to stimulate muscle contraction Very efficient at specifically strengthening weak muscles Patient should perform a physiological contraction at the same time Electrically stimulated contraction have a rapid and jerky response

Neuromuscular Electrical Stimulator(NMES) or Functional Electrical Stimulator used to stimulate innervated muscle To increase strength and improve muscle control in patients with Central Nervous System (CNS) damage,for example stroke,CP( as long as the peripheral motor nerve is intact)

Denervated muscle Muscle becomes denervated by nerve injury Nerve no longer contracts voluntarily/physiologically Cannot contract using NMES or FES Faradic Stimulator or DC stimulator is used to stimulated denervated muscle

Pain modulation Research has shown that electrical stimulation can modulate/decrease pain Pain is decreased by interference with transmission at the Spinal cord level or gate control theory of pain Transcutaneous Electrical Nerve Stimulator(TENS) used to modulate pain

Tissue Healing Some studies have shown that electrical stimulation can enhance healing of soft tissue

Iontophoresis Use of low amplitude DC to facilitate transdermal drug delivery Based on the principle that like charges repel Fixed charged electrode on the skin can drive charged ions of a drug through the skin by pushing away them away Dexamethasone or lidnocaine

Contraindications of Electric currents Pacemaker or history of heart problems Placement of electrode over carotid sinus Pregnancy Venous or arterial thrombosis Malignant tumors

To apply electrical pulses to the tissues a complete circuit is needed so two electrodes with suitable conducting material are fixed to the skin. The effects will be evident where the current density is highest, i.e. in the superficial tissues under the smaller (active) electrode. Consequently he cutaneous sensory nerves are affected first and with greater current

Electrode placement Should not be placed over bony prominences Distance of the spacing between the electrodes affects the depth of current The greater the distance between the electrodes,the deeper the current travels

Application technique Patient positioning Electrode type Electrode placement

Documentation Area of the body to be treated Patient positioning Treatment duration Stimulation parameters Electrode placement Patient response

TENS Conventional TENS Low rate TENS Burst Mode TENS