Electrical currents in Physical therapy

Question	Answer
Acupuncture like TENS amplitude is?	visible contraction
Acupuncture like TENS on:off	continuous
Acupuncture like TENS pulse duration is?	200-300 pps
Acupuncture like TENS releases what?	endorphins
Acupuncture like TENS treatment time is?	20-30 min
Acupuncture like TENS frequency is?	2-10 pps
Acidic reaction (+)	Hydrochloric acid forms under the positive electrode, less uncomfortable than alkaline reaction
acute edema (inflammation) amplitude is?	comfortable tingling sensation
Acute edema (inflammation) frequency is ?	100-120 pps
acute edema(inflammation) on:off is	continuous
acute edema(inflammation) polarity is?	Negative
acute edema(inflammation) pulse duration is ?	40-100us
acute edema (inflammation) treatment time is?	20-30 min
Acute edema(inflammation) waveform is?	HVPC
Adverse effects to e-stim	electrical burns, skin reaction to the electrodes, pain
Alkaline reaction (-)	sodium hydroxide forms under the negative electrode. causes discomfort, skin irritation or chemical burns, reduced likelihood by increasing the size of the negative electrode
Alternating current	continuous and bidirectional flow of charged particles (+ and -)
Amplitude Modulation	usually referred to as scan
Amplitude	magnitude of the current or voltage
Anode	Positive pole
AP are all or none	increased amplitude or duration doesn't increase strength of the AP
What is an AP?	nerves communicate with one another through the production of action potentials(AP), created by depolarization and repolarization of nerves
Benefits of IFC	more comfortable as it has a low amplitude current when going through the skin, delivers higher current in deeper tissues--continuous AC with increase average amplitude, stimulates a larger area
Burst mode TENS is used to?	combines conventional and acupuncture TENS, stimulated endogenous opiates like low-rate TENS but may be tolerated better, provides pain relief similar to high rate TENS
Cathode	Negative pole
chronic edema (due to lack of motion) amplitude is?	visible contraction
chronic edema(due to lack of motion) frequency is?	35-50 pps
chronic edema (due to lack of motion) on:off time?	2-5 on, 2-5 off. 1:1
chronic edema (due to lack of motion) pulse duration is?	150-350= small muscles, 200-350= large muscles
chronic edema (due to lack of motion) ramp?	>1 sec
chronic edema (due to lack of motion) treatment time is?	20-30 min
chronic edema (due to lack of motion)waveform is?	biphasic or IFC
common medication used in iontophoresis	Dexamethosone (0.4 % solution (-), corticosteroid that acts as an anti-inflammatory, useful with tendinitis or bursitis
Conventional or high rate TENS is used for ?	pain control
conventional TENS amplitude is?	tingling
conventional TENS frequency is?	100-150pps
conventional TENS on; off is?	continuous
conventional TENS pulse duration is?	50-80 us
conventional TENS time of treatment is?	up to 24 hrs a day
conventional TENS utilizes the gate theory of pain control where?	spinal cord level
Depolarize	Na+ channels open fast, Na+ rushes in to make inside more positively charged.
Frequency	Number of cycles or pulses per second
General parameters for low rate or acupuncture like TENS are?	longer pulse duration, higher amplitude (visible contraction), treatment must be less than 30 minutes to prevent DOMS.
General parameters of Conventional or High rate TENS are	short pulse duration, comfortable amplitude (strong but comfortable), can be used constantly
HVPC is used for?	Tissue healing (speed healing process)
IFC amplitude of current	higher amplitude current when both are in the same phase and a lower amplitude current when they are in opposite phases
IFC beat frequency =	difference between the frequencies of the original AC's (usually set by machine)
IFC Carrier frequency=	slower original AC (ex: 4100 Hz frequency interferes with 4000 Hz frequency
Gate Control Theory:	pain signals travel up A delta and C nerves. Messages from the brain via descending fibers or peripheral A beta fibers can block pain signals in a hypothetical "pain gate" in the spinal cord
Interpulse Interval	Time between pulses
Iontophoresis amplitude is?	Patient tolerance, no more than 4mA
Iontophoresis polarity is?	same as drug (drives drug into skin)
Iontophoresis time of treatment is?	depends on amplitude
iontophoresis total dose=	40mA. min
Iontophoresis waveform is?	DC
motor nerves do what?	(Efferent) will always submit motor info to the muscles, higher amplitude and longer pulses are required to depolarize.
muscle contraction for denervated muscles	helps slow the process of muscle atrophy and tissue fibrosis formation, continuous DC with longer pulse duration can allow denervated muscles to contract; may slow nerve regeneration, so should not be used if this is the goal
muscle reeducation amplitude is?	functional activation of muscle
muscle reeducation frequency is?	35-50 pps
muscle reeducation on:off time?	varies based on functional activity
muscle reeducation pulse duration is?	150-200 =small muscles, and 200-350= large muscles
muscle reeducation ramp is?	> 2 sec
muscle reeducation time of treatment is?	depends on functional activity
muscle spasm amplitude?	visible contraction
muscle spasm frequency is?	35-50 pps
muscle spasm on:off time	2-5 sec on/2-5 sec off; 1
muscle spasm pulse duration is?	150-200= small muscles,200-350= large muscles
muscle spasm ramp?	> 1 sec
muscle spasm time of treatment	10-30 min
muscle strengthening frequency is ?	35-80pps
muscle strengthening pulse duration is?	150-200= small muscle and 200-350=large muscles
muscle strengthening Ramp is	> 2 sec
muscle strengthening is treated how often ?	every 2-3 hours patient is awake
muscle strengthening amplitude is?	> 10% MVIC if injured, > 50% MVIC if uninjured, visible contraction
muscle strengthening on; off is?	6-10 on; 50-120 off, 1:5 ratio initially
muscle strengthening time of treatment is?	10-20 min (to produce 10-20 reps)
Galvanotaxis:	cells are attracted to electrical charge.
Negative electrode attracts	activated neutrophils ( present with infection or inflammation) lymphocytes, platelets and mast cells, fibroblast. Used for infected or inflamed wounds, acute stage of healing.
Positive electrodes attracts?	inactive neutrophils and macrophages, epidermal cells. Used with necrosis without inflammation and wounds in the proliferation stage; clean wounds.
Premodulated Current	Similar to IFC but uses only one channel; not as effective as IFC
principle of muscle strengthening overload principle	Greater load-->greater force production-->greater strength
Propagation speed is what?	depends on nerve diameter and myelination
Pulse duration	Time from the beginning of the first phase of a pulse to the end of the last phase of a pulse
Pulsed current	an interrupted flow of charged particles where the current flows in a series of pulses separated by periods when no current flows
Ramp up/Ramp down time	ramp up is the time it takes current amplitude to go from 0 to maximum amplitude for any one on time. Ramp down is the time it take for the current amplitude to decrease from its max amp during on time back to zero.
Repolarize=	Na+ channels close and K+ channels open to allow K+ out of the cell and the membrane repolarizes to resting state
Resting potential is	when a nerve is at rest, inside of cell is more negative than outside of cell (b/c most sodium ions outside, most potassium ions inside)
Rise Time/Decay Time	Rise Time is the time it takes current to go from 0 to peak during any one phase; Decay time is the time it takes current to decrease from peak to zero in any one phase
Russian Protocol	2500Hz carrier AC frequency with 50 burst per second, each burst is 10 ms followed by a rest interval of 10 ms.
Sensory nerves do what?	(Afferent) will always submit sensory info to the brain,also low current amplitude and shorter pulse duration depolarize
tissue healing polarity is?	+ for clean wound, --for infection
tissue healing amplitude is?	comfortable tingling sensation
Tissue healing frequency is?	60-125 pps
Tissue healing occurs through?	attraction of cells for tissue healing (neutrophils, leukocytes,)reduction of edema, increased antimicrobial activity, promotion of circulation,increased synthesis of DNA and collagen most effective at healing pressure ulcers
tissue healing on:off is?	continuous
tissue healing pulse duration is?	40-100us
tissue healing treatment time is?	45-60 min
Tissue healing waveform is?	HVPC
Transdermal drug delivery (Iontophoresis)	use a low voltage DC to move charged ions across the dermis by increasing the permeability of th stratum corneum, penetration is likely 3-20 mm, current must be the least sufficient to overcome the resistance of th skin and electrode
Wavelength	Duration of one cycle of AC
What happens to an AP during Depolarization?	The neuron is rapidly depolarized by the opening of voltage-gated Na+ channels. Na+ is pulled into the cell by the negative charge inside and because of the larger concentration of Na+ outside the cell.
What happens to an AP during Repolarization?	The Na+ channel close and voltage-gated K+ channels open to repolarize nerve. K+ is pushed out of the cell because of the large concentration of K+ inside of the cell and because of the positive charge inside the cell.
What is absolute refractory period?	when the membrane is depolarized, it is not possible to create another AP
What is accommodation?	decreased response to same amplitude of nerve stimulation, must rise fast enough that nerve cannot acclimate to the current produced.
what is Beat frequency?	4100Hz-4000Hz=100Hz
what is burst duration?	time from beginning to end of the burst
what is Burst mode?	series of pulsed delivered in an "packet" as a single pulse, frequency and duration preset
what is Chronaxie?	minimum duration to stimulate nerve at twice rheobase (measures time/duration)
What is decay time?	time it takes form peak to decrease to 0 during a phase
What is Duty cycle?	ration of on time to total cycle time, On 10 sec, off 50 sec=10;60 or 1;6 duty cycle
What is electric current (I)?	the flow or movement of charged particles
what is frequency modulation?	varying the number of pulses or cycles per second , usually referred to as sweep
what is interburst interval?	time between burst
what is interferential current (IFC)?	waveform produced by the interference of 2 medium frequency sinusoidal AC's of slightly different frequencies
What is Interphase interval?	time between phases of a pulse
what is modulation?	any variation, cyclic or random, of one or more of the stimulation parameters, limits adaptation of the neurons to current
what is On/Off Time?	On Time is the time when a train of pulses occurs; Off Time is the time between the train of pulses when no current flows.
What is Phase duration?	duration of one phase of the pulse
what is relative refractory period?	after depolarization occurs, a short hyperpolarization period occurs, a stronger than normal AP would be required to produce another AP
what is Rheobase?	minimum amplitude required with a long pulse duration to produce an AP (measures amplitude)
What is Saltatory conduction?	impulse jumps between spaces in myelin sheaths, known as nodes of Ranvier, this leads to greater speed of impulse conduction
What is Strength-duration curve?	minimum amount of electrical current (combination of amplitude and pulse duration) required to depolarize the nerve and produce an AP in a specific type of nerve.
Clinical applications of E-stim:	("MR.PHET") Musc.strengthening, Re-education of musc., Pain, Healing, Edema, Transdermal drug delivery
Clinical effects of e-stim are result of the current stimulating:	action potentials
E-stim to anterior tibialis muscle to produce dorsiflexion during the swing phase of gait is an example of:	FES- functional electrical stimulation
Phase:	in a pulsed current, when starts to flow in one direction to when it stops or starts to flow in other direction
Pulse:	in a pulsed current, period when flows in any direction
Innervated muscle stimulation:	NMES-neuromuscular electrical stimulation (depolarization of nerve)
Denervated muscle stimulation:	EMS-electrical muscular stimulation (depolarization of muscle)
Motor Point:	the place where electrical stimulus will produce the greatest contraction with least amount of electricity. Most motor points are over the middle of the muscle belly.
Current Density:	amount of current delivered per unit area
Adaptation:	a decrease in frequency of AP's and subjective sensation of stimulation that occurs in response to electrical stimulation with unchanging characteristics
Monophasic:	a series of pulses where the charged particles move only in one direction
Biphasic:	a series of pulses where the charged particles move in one direction and then in the opposite direction
Electrodes should not be placed over:	bony prominences...(b/c the higher resistance of bone and poor adhesion of electrodes to highly contoured surfaces increases risk of discomfort and burns, and is less likely to produce therapeutic benefits.
Pt.position for muscle strengthening:	limb should be secured to prevent motion thru the range, with the joint that the stimulated muscles cross in midrange.
Effects of electrode spacing:	closer together=current travels more superficially; further apart=current goes deeper
Waveform used for muscle contraction:	pulsed biphasic or Russian
Waveform used for pain:	pulsed biphasic or IFC
Waveform used for healing:	monophasic or HVPC
Contraindications for E-stim:	("PT CuP"--thx Joey!) Pacemaker or unstable arrythmias, Thrombosis/thrombophlebitis, Carotid sinus, Pregnancy—over abs/low back
Precautions for E-stim:	("IC MIA") Impaired sensation/mentation, Cardiac disease, Malignant tumors, Ionto. After other PA's, Areas of skin irritation/open wounds