MSK Diag Mgt 7220 Exam III - Estim
what is the carrier frequency? what is a typical carrier frequency?
frequency of pulses within a burst
50 bursts/second 2500 Hz
if you want the current to penetrate more deeply, should you move the electrodes further apart or closer together?
if you want a high current density, should you cut the electrode in half or keep the original size?
cut it in half - smaller electrodes = higher current density.
are each of the following good current conductors or poor current conductors
peripheral nerve good
higher water content means better conductance
precautions of estim
stimulation across chest
excess adipose tissue
contraindications of estim
over carotid sinus
pregnancy - at or around the abdomen
phase duration for sensory stimulation
phase duration used for muscle contraction
150 to 350 us
what pulse duration must e stim be under in order for C fibers not to depolarize
frequencies for muscle contraction
what percentage of MVIC should be achieved for strength gains in estim
through what mechanisms does estim treat spasticity
agonist through fatigue
antagonist through reciprocal inhibition
waveform: symmetrical or assymetrical biphasic pulsed current or burst modulating alternating current
pulse duration 150 - 600 ms
frequency 30-80 Hz
amplitude - enough to obtain a strong muscle contraction
ramp up 1-5 seconds
ramp down 1-2 second
duty cycle 1:3 to 1:5 with on time up to ten seconds
if you chose pulsed monophasic as your mode to treat a person, would you put the anode or cathode at the desired site of contraction
which estim strengthening mode is equivalent to NMES
using estim concurrently with movement in order to DF assist during walking or gait retrain after SCI would be examples of
FES functional electrical stimulation
pain modulation theory for sensory level TENS
gate control theory
pain modulation theory for motor level TENS
endogenous opiate release theory
pain modulation theory of noxious TENS
descending pain control
endogenous opiate relief
vascular effects of estim for pain
increase in regional blood flow due to mechanical muscle pump (at motor level only)
vasodilation possibly due to increase in sympathetic activity
settings for edema tx with estim
frequency 8-30 pps
PD 25 ms
in the inflammatory stages of healing, would you want to appy a positive or negative charge to the area of injury? why?
the cells with a role in healing in this phase are macrophages and neutrophils which are negatively charged so you would want to apply a positive charge
In the proliferative and remodeling stages, apply neg or pos charge to injury
neg charge because fibroblasts are positive (proliferative) and myofibroblasts and kertinocytes (remodeling)
range of penetration for iontophoresis
which drugs common in iontophoresis are negatively charged?
dexamethasone (a common glucocorticoid--> cathode would be active,
acetic acid, iodine, salicylates
which drug common in iontophoressis is positively charged?
would you use anode or cathode to break up scar tissue? why
As the anode (+) produces an acid reaction (a weak HCL acid), it is considered sclerotic, which tends to harden tissues, serving as an analgesic agent due to local release of oxygen. On the other hand, as the cathode (-) produces an alkaline reaction (a strong sodium hydroxide), it is then considered sclerolytic, which is a softening agent due to the hydrogen release, serving in the management of scars and burns.
which modality is indicated for hiperhidrosis?
typical dosage for iontophoresis?
where should the electrodes be placed in electrophysiologica testing?
active recording electrode on muscle belly, reference electode on tendon, and ground electrode between the two.
what is the amplitude of response representative of in electrophysiologic testing?
number of functioning motor units innervated by nerve being tested
loss of perineurium
neurapraxia - loss of conduction due to blockage. lasts 6-8 weeks. mild. myelin damage. blunt damage.
axonotmesis -myelin and axon damage. more severe crush,stretch or contusion than neurapraxia. middle severity. recovery 6-12 months.
endoneurial and perineurium - perineurium superficial sheath. endoneurial deeper. (partial neurotmesis)
neurotmesis - entire nerve is damaged. no recovery.
clinical indications of UV radiation
contraindications of UV tx
avoid the eyes
skin cancer, pulmonary tuverculosis, cardiac kidney or liver disease, fever
sun burn --> release of histamine --> microvascular vasodilation
minimal erythemal dose
smallest does causing burn within 8 hours of exposure and disappears within 24 hours
desired effects of LLLT (low-level laser therapy)
alters cell membrane and function
increased ATP and nucleic acid production
stimulation of macrophages and fibroblasts --> increased collagen production
change in NCV regeneration
for which modality do contraindications and precautions include areas of hemorrhage, epilepsy, fever, lumbar region during pregnancy, and over endocrine gland?
major difference between the capacitive method of SWD and the inductive method. which heats mostly muscle?
capacitive is heating by electric field and inductive is heating by magnetic field. inductive method heats mostly muscle
the bacterialcidal and ionizing band of UV radiation
NO METAL IMPLANTS
obesity and excessive adipose tissue
adjacent electronic or magnetic equipment
are contraindications and precuations of which modality