Minerva Zaniebeth A. Gomez, PTRPDepartment of Physical TherapyCollege of Allied Medical ProfessionsUniversity of the Philippines-ManilaAll rights reserved. Copyright by MZAG, 2009. Use exclusively for PT 158: Physical Agents iII. Approval and consent from Minerva Zaniebeth A. Gomez and University of the Philippines-Manila required before use for other purposes. (mzagomez@upm.edu.ph)

1. Describe Alternating Currents (AC) according to:

• Physical properties• Classification

– Uneven (Faradic currents)– Even (Sinusoidal currents)

Learning Objectives:Learning Objectives:

2. Identify the physiological effects and therapeutic effects of:a. Uneven ACb. Even AC

3. Differentiate the precautions/ contraindications of:a. Uneven ACb. Even AC

4. Select appropriate treatment parameters for indicated cases/ conditions.a. Uneven ACb. Even AC

5. Describe Functional Electrical Stimulation and its therapeutic uses.

6. Select appropriate treatment parameters when using FES for different cases/ conditions.

7. Appreciate evidence on the use of FES

ALTERNATING CURRENT ALTERNATING CURRENT

FARADIC Uneven AC

SINUSOIDAL Even AC

Cont. Interrupted

Freq:50 HzPD: 1 ms

Freq: 50 HzPD: 10 ms

Cont. Interrupted

Alternating Current• Periodic changes of the direction

of electron flow in a rhythmic manner NO NET ion transfer

• Frequency used medically is 50 Hz

Alternating Current• Not possible to cause burns,

unless in high intensities• Surged or unsurged

Uneven AC/ Faradic• Two phases• PD: 1 ms• No polarity

needed• Surged• Mild prickling

sensation

• NO chemical effects• Similar to physiological effects of

faradic type currents• Indication and contraindication is

the same with faradic-type currents/ SIDC

Uneven AC/ Faradic

Even AC/ Sinusoidal• Sine curve• PD: 10 ms• Surged or unsurged• No polarity needed

• Indication: Swelling and pain EXCEPT referred & psychosomatic type

• Contraindication: Skin lesion, Infection, Impaired sensation

Indications and Contraindications

• Sensory nerves: Marked prickling sensation longer duration

• Motor nerves: Tetanizes, with a sequence of contraction followed by relaxation

• NO chemical effects

Physiological Effects

• Swelling: Absorption of exudate• Circulation: Superficial

vasodilation via axon reflex (capillary vasodilation) hyperaemia

Physiological Effects

• Facilitate muscle contraction• Re-educate muscle action• Train new muscle action• Exercise for paralyzed muscles• Hypertrophy• Increase strength• Improve circulation • Prevent and loosen adhesions

Therapeutic Effects of Even and Uneven AC

Functional Electrical Stimulation• Functional NMES• Used for: -disuse atrophy

- impaired ROM - ms spasm - ms reeducation - spasticity - supplement to orthotic devices

FES for Shoulder Subluxation

• Waveform: Asymmetrical biphasic square

• Modulation: Interrupted

FES for DF Assist in Gait Training• Waveform:Assymetrical biphasic square

• PD: 20-250 µsec• Modulation:

interrupted by foot switch

FES for Scoliosis Management

• Selection Criteria:– Curves measuring 20-45 deg. (Cobb)– At least 1 year of spinal growth

remaining– An idiopathic and progressive nature

of the curve– Cooperative and psychologically

stable– Compliant and tolerant to stimulation

Evidence in Practice

Pomeroy V. M., King, L., Pollock, A., Baily-Hallam, A., and Langhorne, P. (2006). Electrostimulation for promoting recovery of movement or functional ability after stroke. Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD003241. DOI:10.1002/14651858.CD003241.pub2.

Can FES help improve UE motor recovery of a patient at acute-subacute phase post-stroke?Minerva Zaniebeth A. Gomez, PTRP, PT 158 faculty AY 2008-2009(

mzagomez@upm.edu.ph), Ma. Liezel Bumanglag, Justine Charlotte Garcia, Marinelle Rabang, Michiko Alla Uy

FES of hand extensors

Evidence in Practice

• There is significant change in upper extremity function with the use of electrical stimulation compared to no treatment.

• Low internal validity (single studies) low power

Evidence in Practice

• Wide confidence interval crosses zero point

• Heterogenous settings of parameters used “FES” loosely used term among PTs.

References:References:Gersh, M. R. (1992). Electrotherapy in

Rehabilitation. USA: F.A. Davis Company.Hecox, B., Mehreteab, T. A., & Weisberg, J.

(1994). Physical Agents: A Comprehensive Text for Physical Therapist. Appleton & Lange.

Wadsworth, H., & Chanmugam, A. (1988). Electrophysical Agents in Physiotherapy. Singapore: Science Press.

 Revised ACDC lecture of Ms. Jazel Ann Atienza, PTRP