Week 3 E Stim Lecture Pt 2 (Clinical Application) Flashcards
Cellular effects of electrical current
Excitation of nerve cells
Change in membrane permiability
Protein Synthesis
Stimulation of fibroblasts and osteobalsts
modification of microcirculation
Tissue level effects of Electrical current:
Muscle fiber (skeletal and smooth) contraction
Tissue regeneration
Segmental effects of E-Stim
Modification of joint mobility
muscle pumping action (lymphatics)
Alteration of microvascular system
increase in movement of charged proteins into lymphatic channels
Systemic effects of E- Stim
Analgesic effects
What kind of E-Stim is our first choice for pain?
IFC
What are the 4 clinical stimulation levels?
Subsensory
Sensory- tingling/prickling feeling
Motor- Strong paresthesias, muscle contraction
Noxious- Strong uncomfortable paresthesias, strong muscle contraction, burning sensation
What is a “motor point”
Point located above the skin where you can place the electrode to get the most muscle twitch with the least current
AKA area with least resistance
What are uses of High Voltage Currents (HVPC)
Muscle contraction
reducing Edema
Wound healing
Pain control (but IFC and TENs are preferred over this)
What do the waves look like for HVPC?
Twin peak monophasic pulsed wave forms
How do you apply HVPC?
2 unequal sized electrodes
Active electrode: smaller one placed over treatment site
Dispersive electrode : Large electrode placed somewhere away from treatment site
Negative polarity HVPC is most effective in what phase of healing?
Inflammatory phase
Positive polarity HVPC is most effective in what phase of healing?
Proliferation phase
When using HVPC for edema, what settings should you use?
Frequency: 120pps
Intensity: 30-50V (10% less than what’s needed to produce a muscle contraction)
Duration: 30 minutes
What kind of E-Stim uses gate control theory/descending control theory?
TENS (Transcutaneous Electrical Nerve Stimulation)
Where can you put the electrodes for a TENs unit?
Almost anywhere that there is pain
Conventional TENS vs
Acupuncture-like TENS
Conventional: High rate, low intensity (best for acute pain)
Uses gate control theory
Acupuncture - Low rate, high intensity (best for chronic pain)
Uses descending control theory
What are the 4 types of TENS
Conventional
Acupuncture
Noxious Level
Brief Intense
What kind of TENS is best for wound debridement?
Brief Intense (high rate and high intensity)
What should the settings be for conventional TENS?
Frequency 80-125 (100)
Duration 75-150 (100)
Intensity: Tolerable SENSORY stimulation (no muscle contraction)
How long can you use conventional TENS?
30 mins to a couple hours
What is gate control theory?
Increasing activity of A-Beta fibers triggers release of enkephalin from interneurons whcih inhibit second order neurons of pain
What are the settings for acupuncture-like TENS
Frequency : LOW 1-20 pps
Duration : 100-600 (Remember we set it to 250 which is the max the machine in lab can do)
Intensity: Enough to ilicit sensory and muscle contraction
How long should you use acupuncture-like tens?
15 mins
How does descending pain control theory work?
Opiate receptors in central or peripheral terminals of nociceptive afferent fibers
“basically pain is tricked into not crossing into spinal cord” - Dr G
What are the settings of Noxious level TENS?
LOW frequency 1-5
Duration 100-1000
Intensity: set to noxious level w/ possible muscle contraction
FOR trigger points/acupuncture points
What kind of TENS uses endogenous opiate pain control theory
Noxious level TENS
Settings for brief intense TENS?
frequency 100pps
Duration 100-600
intensity: Muscle fasciculation to sustained muscle contraction
What are 2 uses of russian current?
Muscle Strengthening
Muscle re-education
Should russian E-Stim be a substitute for therapeutic exercise?
no
What is the normal frequency of Modern Russian Current?
2000-10000 hz
(waves look like solid blocks of smaller waves)
What are the advantages of russian current?
Why is the frequency so high?
Higher frequency reduces resistance making the waveform tolerable enough at high intensities
As soon as nerve repolarizes its already stimulated again, leading to maximal summated muscle contractions
What are 2 uses of IFC?
Pain Control
Muscle stimulation (reduce spasm)
How are the electrodes placed for IFC?
In a cross pattern, each channel is diagonal
How does IFC work?
2 different current paths interfere with eachother and the frequency is actually the difference between the 2 diagonal frequencies
Example: 4100 one way and 4000 the other way = 100hz in the middle
What is IFC sweep mode?
Allows frequencies to be modulated to avoid accomodation
What is interferential current scan mode?
Scan mode allows the AMPs to be modulated, increases the area of interference
Example: if patient has poorly localized pain this allows it to cover more area
What is IFC target mode?
You can select what area between the 4 pads you want to focus on, reduces accomodation by changing the location of the current
What is the “little brother” of IFC called?
Pre-MOD
How does pre-mod work?
2 currents interfere with each other inside the device before being delivered to the patient
basically IFC with only 2 electrodes
E-Stim contraindications:
Pace makers
Stimulation near heart
Area over carotid sinus
Area with DVT or thrombsis
Patients who are confused
Patients w/ internal stimulator
Name more?
seizure disorders
Infection
Wounds,scars,lesions
Malignancies
pregnancy
MSK problems where it would exacerbate the condition
high level spinal cord injury
E-Stim Contraindication:
seizure disorders
Infection
Wounds,scars,lesions
Malignancies
pregnancy
MSK problems where it would exacerbate the condition
high level spinal cord injury
Name more?
Pace makers
Stimulation near heart
Area over carotid sinus
Area with DVT or thrombsis
Patients who are confused
Patients w/ internal stimulator
What is the normal rule for electrode placement (distance)?
Electrodes must be atleast 1.5x the electrode diameter apart
How should electrodes be oriented on a muscle?
Parallel to the muscle fibers
Small vs large electrodes
Small: increase current density
increased impedance
decrease flow
Large: Decrease current density
decrease impedance
increase flow
Muscle fibers are ____________ ______ conductive when the electrodes are placed parallel to the fibers vs perpendicular to them
x4 more
Conventional TENs works on what fibers?
A-Beta fibers
Motor level/low rate TENs works on what fibers?
A-Beta
Motor
and possibly A-Delta
What is the “Hot finger” technique?
- Set pulse rate between 80 - 150
Set pulse duration (width) between 50 - 150
(Basically 100 100) - Apply 1 electrode on yourself and the other on your patient
- Using your fingertip, contact on your patient
(aim for the motor point) - Turn the unit on and raise the amplitude until you feel a mild tingling. Slowly move your finger over the skin.
- When you come on to a low impedance point, you will feed a greater current flow
through your finger
What technique helps you find a low impedence point for placing an electrode?
hot finger technique
What is carrier frequency of IFC?
What is beat frequency?
Carrier- the lesser frequency current of the 2. Example: you’ve got 4000 and 4100, so 4000 is the carrier frequency
Beat- The difference of the frequencies (example: 4100-4000 = 100)
When using NMES, what frequencies do small muscles get, what about big muscles?
small muscles 200-300; large muscles 300-600
When using NMES, the higher the pulse frequency the ___________ the fatigue
faster
When using NMES, the longer the pulse duration the __________ frequency needed for tetany, and the patient experiences an ______ discomfort
Lower
Increased
