Pain Management
with Pulsed Electromagnetic Field (PEMF) Treatment
© 2003 William
Pawluk M.D., MSc
The issue of pain treatment
is an extremely urgent health and socio-economic problem. Pain,
in acute, recurrent and chronic forms, is prevalent across age,
cultural background, and sex, and costs North American adults
an estimated $10,000 to $15,000 per person annually. Estimates
of the cost of pain do not include the nearly 30,000 people that
die in North America each year due to non-steroidal anti-inflammatory
drug-induced gastric lesions. 17% of people over 15 years of
age suffer from chronic pain that interferes with their normal
daily activities. Studies suggest that at least 1 in 4 adults
in North America is suffering from some form of pain at any given
moment. This large population of people in pain relies heavily
upon the medical community for the provision of pharmacological
treatment. Many physicians are now referring chronic pain sufferers
to non-drug based therapies, that is, "Complementary and
Alternative Medicine," in order to reduce drug dependencies,
invasive procedures and/or side effects. The challenge is to
find the least invasive, toxic, difficult and expensive approach
possible.
The ability to relieve
pain is very variable and unpredictable, depending on the source
or location of pain and whether it is acute or chronic. Pain
mechanisms are complex and have peripheral and central nervous
system aspects. Therapies should be tailored to the specifics
of the pain process in the individual patient. Psychological
issues have a very strong influence on whether and how pain is
experienced and whether it will become chronic. Most effective
pain management strategies require multiple concurrent approaches,
especially for chronic pain. It is rare that a single modality
solves the problem.
Static or electromagnetic
fields have been used for centuries to control pain and other
biologic problems, but scientific evidence of their effect had
not been gathered until recently. This review explores the value
of magnetic therapy in rehabilitation medicine in terms of static
magnetic fields and time varying magnetic fields (electromagnetic).
A historical review is given and the discussion covers the areas
of scientific criteria, modalities of magnetic therapy, mechanisms
of the biologic effects of magnetic fields, and perspectives
on the future of magnetic therapy.
In the past few years a
new and fundamentally different approach has been increasingly
investigated. This includes the use of magnetic fields (MF),
produced by both static (permanent) and time-varied (most commonly,
pulsed) magnetic fields (PEMFs). Fields of various strengths
and frequencies have been evaluated. There is as yet no "gold
standard". The fields selected will vary based on experience,
confidence, convenience and cost. Since there does not appear
to be any major advantage to any one MF application, largely
because of the unpredictability of ascertaining the true underlying
source of the pain, regardless of the putative pathology, any
approach may be used empirically and treatment adjusted based
on the response. After thousands of patient-years of use globally,
there very little risk has been found to be associated with MF
therapies. The primary precautions relate to implanted electrical
devices and pregnancy and seizures with certain kinds of frequency
patterns in seizure prone individuals.
Magnetic fields affect
pain perception in many different ways. These actions are both
direct and indirect. Direct effects of magnetic fields are: neuron
firing, calcium ion movement, membrane potentials, endorphin
levels, nitric oxide, dopamine levels, acupuncture actions and
nerve regeneration. Indirect benefits of magnetic fields on physiologic
function are on: circulation, muscle, edema, tissue oxygen, inflammation,
healing, prostaglandins, cellular metabolism and cell energy
levels.
Most studies on pain use
subjective measures to quantitate baseline and outcome values.
Subjective perception of pain using a visual analogue scale (VAS)
and pain drawings is 95% sensitive and 88% specific for current
pain in the neck and shoulders and thoracic spine.
Measured pain intensity
(PI) changes with pain relief and satisfaction with pain management.
A 5%, 30%, and 57% reduction in PI correlated with "no,"
"some/partial," and "significant/complete"
relief. If initial PI scores were moderate/severe pain (NDS >
5), PI had to be reduced by 35% and 84%, to achieve "some/partial"
and "significant/complete" relief, respectively. Patients
in less pain (NDS < or = 5) needed 25% and 29% reductions
in PI. However, relief of pain appears to only partially contribute
to overall satisfaction with pain management.
Several authors have reviewed
the experience with PEMFs in Eastern Europe and the West. PEMFs
have been used extensively in many conditions and medical disciplines.
They have been most effective in treating rheumatic disorders.
PEMFs produced significant reduction of pain, improvement of
spinal functions and reduction of paravertebral spasms. Although
PEMFs have been proven to be a very powerful tool, they should
always be considered in combination with other therapeutic procedures.
Since the turn of this
century, a number of electrotherapeutic, magnetotherapeutic and
electromagnetic medical devices have emerged for treating a broad
spectrum of trauma, tumors and infections with static and PEMFs.
Their acceptance in clinical practice has been very slow in the
medical community. Practitioner resistance seems largely based
on confusion of the different modalities, the wide variety of
frequencies employed (from ELF to microwave) and the general
lack of understanding of the biomechanics involved. The current
scientific literature indicates that short, periodic exposure
to pulsed electromagnetic fields (PEMF) has emerged as the most
effective form of electromagnetic therapy.
The ability of PEMFs to
affect pain is dependant on the ability of PEMFs to positively
affect human physiologic or anatomic systems. Research is showing
that the human nervous system is strongly affected by therapeutic
PEMFs. Behavioral and physiologic responses of animals to static
and extremely low frequency (ELF) magnetic fields are affected
by the presence of light. Light strengthens the effects of PEMFs.
One of the most reproducible
results of weak, extremely low-frequency (ELF) magnetic field
(MF) exposure is an effect upon neurologic pain signal processing.
PEMFs have been designed for use as a therapeutic agent for the
treatment of chronic pain in humans. Recent evidence suggests
that PEMFs would also be an effective complement for treating
patients suffering from acute pain. Static magnetic field devices
with strong gradients have also been shown to have therapeutic
potential. Specifically placed static magnets reduce neural action
potentials and alleviate spinal mediated pain. The placebo response
may explain as much as 40% of an analgesia response. The central
nervous system mechanisms responsible for the placebo response
are an appropriate target for magnetic therapies. Magnetic field
manipulation of cognitive and behavioral processes is seen in
animal behavior studies and in humans. This may also be one of
the mechanisms of the use of MFs in managing pain.
Some of the mechanisms
of PEMF effects
Magnetotherapy is accompanied
by an increase in the threshold of pain sensitivity and activation
of the anticoagulation system. PEMF treatment stimulates production
of opioid peptides; activates mast cells and increases electric
capacity of muscular fibers. Long bone fractures that did not
unite over 4 months to 4 years are repaired in 87% of cases with
14-16 hr of daily PEMF treatment. Several of these devices are
FDA approved. PEMF of 1.5- or 5-mT field strength, proved helpful
edema and pain before or after a surgical operation.
PEMF for 15-360 minutes
increases amino acid uptake about 45%. PEMF for 2 hour induces
changes in transmembrane energy transport enzymes, allowing energy
coupling and increased biologic chemical transport work.
The density of pigeons'
brain mu opiate receptors decreases by about 30% and therefore
their pain perception. A 2 hr exposure of healthy humans was
found to reduce pain perception and decreased pain-related brain
signals. Biochemical changes were found in the blood of treated
patients that supported the pain reduction benefit.
Normal standing balance
is subject to control by the vestibular area of the brain. PEMF
couple with muscular processing or upper body nervous tissue
functions. 200-uT PEMFs cause a significant improvement in normal
standing balance in adult (18-34 year old) humans. Further evidence
of the sensitivity of the nervous system on MFs.
Various MFs with different
characteristics reduce pain inhibition in various species of
animals including land snails, mice, pigeons, as well as humans.
0.5 Hz rotating MF, 60 Hz ELF magnetic fields and even MRI reduces
analgesia induced by both exogenous opiates (i.e. morphine) and
endogenous opioids (i.e. stress-induced). Reduction in stress-induced
analgesia can be obtained not only by exposing animals to a variety
of different magnetic fields, but also after a short-term stay
in a near-zero magnetic field. This suggests that even for magnetic
field, as for other environmental factors (i.e. temperature or
gravity), alterations in the normal conditions in which the species
has evolved can induce alterations in physiology as well as in
behavior.
MFs applied to the head
or to an extremity, for from 1 to 60 minutes, with intervals
from several minutes to several hours, randomly sequenced with
sham exposures allowed study of brain reactions by various objective
measures. From these multiyear studies, the brain shows a non-specific
initial response. The changes were "modulatory", meaning
that the brain was found to sense EMF exposures vs. sham exposures.
The sensory reactions were a weak pain, tickling, pressure, etc.
sensations, mediated by the body's peripheral sensory systems.
Reactions could be prevented by local anesthesia of the exposed
area. EEGs showed increased low-frequency rhythms, more pronounced
when brain damage was present. This explains the common perception
of relaxation and sleepiness with MFs. Cell analysis showed that
all types of brain cells react to EMFs but astrocytes were most
sensitive. They are involved in memory processes and slow wave
brain activity.
The benefits of PEMF use
may last considerably longer than the time of use. In rats, a
single exposure produces pain reduction both immediately after
treatment and at 24 hrs after treatment. The analgesic effect
is still observed at 7th and 14th day of repeated treatment and
even up to 14 days after the last treatment.
PEMFs promote healing of
soft tissue injuries by reducing edema and increasing resorption
of hematomas. Low frequency PEMFs reduce edema primarily during
treatment sessions. PEMFs at very high frequencies (PRFs) for
20-30 minutes cause edema decreases lasting several hours. PRFs
induce vasoconstriction at the injury site. They displace negatively
charged plasma proteins found in traumatized tissue. This increases
lymphatic flow, an additional factor in reducing edema.
In rats exposed for 20
min daily on 3 successive days to PEMFs of 50 mG, the pain threshold
increased progressively over the 3 days. The pain threshold following
the third magnetic field exposure was significantly greater than
those associated with morphine and other treatments. Brain injured
and normal rats both showed a 63% increase in mean pain. PEMFs
may be very helpful in patients with closed head injuries. The
mechanism probably involves the longer acting endorphins rather
than enkephalins.
Chronic pain is often a
result of aberrantly functioning small neural networks involved
in self-perpetuated neurogenic inflammation. High intensity pulsed
magnetic stimulation (HIPMS) noninvasively depolarizes neurons
and can facilitate recovery following injury. Patients suffering
from posttraumatic or postoperative low-back pain, reflex sympathetic
dystrophy, peripheral neuropathy, thoracic outlet syndrome and
endometriosis had pain relief. Up to ten,10-min exposures to
1.17 T at a rate of 45 pulses/minute were applied to the areas
of maximal pain for 6 treatments. One patient became pain free
after 4 HIPMS treatments. All patients reported some pain relief.
Maximum pain relief occurred 3 hr after treatment. Two patients
had complete pain relief and 3 had partial pain relief that lasted
for 4 months. The others had pain relief that lasted for 8-72
hours.
Even weak AC magnetic fields
affect pain perception and pain-related EEG changes in humans.
A 2 hour exposure to 0.2-0.7G ELF magnetic fields caused a significant
decrease in pain-related EEG patterns.
Pain relief mechanisms
vary by the type of stimulus used. For example, needling to the
pain-producing muscle, application of a static magnetic field
or external qigong or needling to an acupuncture point all reduce
pain but by different mechanisms. Pain could be induced by reduction
of circulation in muscle and reduced by recovery of circulation.
Pain mediating substances are accumulated in a muscle under reduced
circulation and reversed with restoration of circulation. This
is why chronic muscle tension is a frequent cause of chronic
pain. The effect of a static magnetic field or external qigong
is mediated by enhanced release of acetylcholine as a result
of activation of the cholinergic vasodilator nerve endings in
a muscle artery. Needling an acupuncture point is probably induced
by a somato-autonomic reflex through the brain, in the anterior
hypothalamus.
In normal subjects, a magnetic
stimulus over the cerebellum reduces the size of responses evoked
by cortical stimulation. Suppression of motor cortical excitability
is reduced or absent in patients with a lesion in the cerebellum
or cerebellar nerve pathways. Magnetic stimulation over the cerebellum
produces the same effect as electrical stimulation, even in ataxic
patients and may be useful for the pain associated with muscle
spasticity.
Clinical benefits
In diabetic neuropathy,
PEMF treatment every day for about 12 minutes, improves pain,
paresthesias and vibration sensation and increases muscular strength
in 85% of patients compared to controls.
One author reported that,
of treated patients followed for 2-60 months, better results
happened in patients with post-herpetic pain and those simultaneously
suffering from neck and low back pain.
Chronic pain is often accompanied
with or results from decreased circulation or perfusion to the
affected tissues, for example, cardiac angina or intermittent
claudication. PEMFs have been shown to improve circulation. Skin
infrared radiation increases due to immediate vasodilation with
low frequency fields and increased cerebral blood perfusion in
animals. Pain syndromes due to muscle tension and neuralgias
improve.
The results of the treatment
depend not only on the parameters of the fields but also on the
individual sensitivity of the person. The most effective results
in clinical use were found with extremely ultra low frequency
PEMFs.
Back, neck and shoulder
pain
Chronic low back pain affects
approximately 15% of the United States (US) population during
their lifetime, with 93 million lost work days and a cost of
more than $5 billion per year. Lumbar arthritis is a very common
cause of back pain. 35-40 mT PEMFs, for 20 minutes daily for
20-25 days for back pain gives relief or elimination of pain,
improves results from other rehabilitation and improves secondary
neurologic symptoms. Continuous use over the treatment episode
works best, in about 90-95% of the time. Control patients only
show a 30% improvement. PEMF of 5 to 15 G, from 7 Hz to 4 kHz
used at the site of pain and related trigger points for 20 to
45 minutes also helps. Some patients remain pain free 6 months
after treatment. Some return to jobs they had been unable to
perform. Short term effects are thought due to decrease in cortisol
and noradrenaline and an increase serotonin, endorphins and enkephalins.
Longer term effects may be due to CNS and/or peripheral nervous
system biochemical and neuronal effects in which correction of
pain messages occurs and the pain is not just masked as in the
case of medication. Back pain or whiplash syndrome treated PEMF
twice a day for two weeks along with usual pain medications relieves
pain in 8 days vs. 12 days in the controls. Headache is halved
in the PEMF group and neck and shoulder/arm pain improved by
one third versus just medications alone. Permanent magnetic therapy
can also be useful in reducing chronic muscular low back pain.
Treatment with a flexible permanent magnetic pad for 21 days
reduces pain 6 times more than placebo. This has been effective
for herniated lumbar discs, spondylosis, radiculopathy, sciatica
and arthritis. Pain relief is sometimes experienced as early
as 10 minutes or in some cases takes as long as 14 days.
Low-power pulsed short
wave 27 Hz diathermy has successfully treated persistent neck
pain and improved mobility. The neck pains lasted longer than
8 wk and did respond to at least 1 course of nonsteroidal anti-inflammatory
drugs. A miniaturized, 9V battery-operated, diathermy generator
was fitted into a soft cervical collar. Treatment is for 3-6
weeks, 8 hr daily. Analgesics can be used as needed and nonsteroidal
anti-inflammatory drugs. 75% of patients improve in range of
motion and pain within 3 wk of treatment.
For neck pain, PEMFs may
have more benefit, compared to physical therapy, for both pain
and mobility.
Other pain applications
High frequency PEMF of
10-15 single treatments every other day either eliminates or
improves, even at 2 weeks following therapy, 80% of patients
with pelvic inflammatory disease, 89% with back pain, 40% with
endometriosis, 80% with postoperative pain, and 83% with lower
abdominal pain of unknown cause.
In dentistry, PEMFs have
also been found only slightly useful in treating dental pain,
jaw muscle spasms and swelling during wisdom tooth extraction
with a high frequency system. As is often seen in pain studies,
a placebo response is high, 30-40% of the time. In periodontal
disease bone resorption may be severe enough to require bone
grafting. Grafting is followed by moderate pain peaking several
hours afterwards. Repeated PEMF exposure for two weeks eliminates
pain within a week. Even single PEMF exposure to the face for
30 minutes of a 5mT field and conservative treatment produces
much lower pain scores vs. controls.
Pelvic pain of gynecological
origin was also found to be benefited by a different high voltage,
high frequency system. This includes ruptured ovarian cysts,
postoperative pelvic hematomas, chronic urinary tract infection,
uterine fibrosis, dyspareunia, endometriosis and dysmenorrhea.
Treatment times vary from 15 to 30 minutes on subsequent or alternate
days. 90% of patients experience marked, rapid relief from pain
with pain subsiding within 1-3 days. Most of these patients don't
require supplementary analgesics.
Post-herpetic neuralgia
(PHN), a very common and painful condition, which is often medically-resistant,
responds to PEMF for 20-30 minutes daily for 19 treatments over
34 days. The PEMF is a 4-16 Hz and 0.6-T samarium/cobalt magnet
system surrounded by spiral coil pads with a maximum 0.1-T pulse
at 8 Hz pasted on the pain/paresthesia areas or over the spinal
column or limbs. Treatments continue until symptoms improve or
an adverse side effect occurred. PEMF therapy is effective in
80%. No pain was made worse. This treatment approach shows that
treatment for pain problems may either be localized to the pain
or done over the spinal column or limbs, away from the pain.
PEMFs applied to the inner
thighs for at least 2 wk is effective short-term therapy for
migraine. Greater reduction of headache activity is achievable
with longer exposure. PEMF using a high frequency signal to the
inner thigh femoral artery area for 1 hr/day, 5 day/wk, for 2
weeks decreases headache. One month after a treatment course,
73% of patients report decreased headache activity vs. only half
of those receiving placebo treatment. Another 2-wk of treatment
after the 1-month follow-up gives an additional 88% decrease
in headache activity. If there is no additional treatment after
an initial course 72% still show a benefit. Placebo patients
getting active treatment afterwards report much better additional
improvement in headache.
Patients suffering from
headache treated with a PEMF after failing acupuncture and medications,
applied to the whole body, 20 min/day for 15 days get effective
relief of migraine, tension and cervical headaches at about one
month after treatment. They have at least a 50% reduction in
frequency or intensity of the headaches and reduction in analgesic
drug use. Poor results are seen in cluster and posttraumatic
headache.
Chronic pain frequently
presented by postpolio patients can be relieved by application
of magnetic fields applied directly over trigger points using
300 to 500 G static magnets for 45 minutes.
Orthopedic or musculoskeletal
uses
The use of PEMFs is rapidly increasing and extending to soft
tissue from its first applications to hard tissue. EMF in current
orthopedic clinical practice is used to treat delayed and non-union
fractures, rotator cuff tendinitis, spinal fusions and avascular
necrosis, all of which can be very painful. Clinically relevant
response to the PEMF is generally not always immediate, requiring
daily treatment for several months in the case of non-union fractures.
PEMF signals induce maximum electric fields in the mV/cm range
at frequencies below 5 kHz. Pulse radiofrequency fields (PRF)
consist of bursts of sinusoidal waves in the short wave band,
usually in the 14-30 MHz range. PRF induces fields in the V/cm
range. PRF signals have higher field strengths than PEMFs. PRF
signals have low frequency bursts nearly equivalent in size to
PEMFs. This means that PRF signals have a broader band. PRF applications
are best for reduction of pain and edema. The tissue inflammation
that accompanies the majority of traumatic and chronic injuries
is essential to the healing process, however the body often over-responds
and the resulting edema causes delayed healing and pain. For
soft tissue and musculoskeletal injuries and post-surgical, post-traumatic
and chronic wounds, reduction of edema is thus a major therapeutic
goal to accelerate healing and associated pain. Double-blind
clinical studies have now been reported for chronic wound repair,
acute ankle sprains, and acute whiplash injuries. PRFs accelerated
reduction of edema in acute ankle sprains by 5-fold. Response
to MFs is during or immediately after treatment of acute injuries.
Responses are significantly slower for bone repair. The voltage
changes induced by PRF at binding sites in macromolecules affect
ion binding kinetics with resultant modulation of biochemical
cascades relevant to the inflammatory stages of tissue repair.
High strength repetitive
magnetic stimulation (rMS) has been found to relieve musculoskeletal
pain. Specific diagnoses were painful shoulder with abnormal
supraspinatus tendon, tennis elbow, ulnar compression syndrome,
carpal tunnel syndrome, semilunar bone injury, traumatic amputation
neuroma of the median nerve, persistent muscle spasm of the upper
and lower back, inner hamstring tendinitis, patellofemoral arthrosis,
osteochondral lesion of the heel and posterior tibial tendinitis.
Patients receive rMS for 40 minutes. Mean pain intensity is 59%
lower vs. 14% for controls. Patients with amputation neuroma
and patellofemoral arthritis obtain no benefit. Those with upper
back muscle spasms, rotator cuff injury and osteochondral heel
lesions showed more than 85% decrease in pain, even after a single
rMS session. Pain relief persists for several days. None have
worsening of their pain.
Osteoarthritis (OA) affects
about 40 million people in the USA. OA of the knee is a leading
cause of disability in the elderly. Medical management is often
ineffective and creates additional side-effect risks. The QRS
has been in use for about 20 years in Europe. The QRS applied
8 min twice a day for 6 weeks improves knee function and walking
ability significantly. Pain, general condition and well-being
also improve. Medication use decreases and plasma fibrinogen
decreases 14%, C-reactive protein ( a sign of inflammation) drops
35% and the blood sedimentation rate 19%. The QRS has also been
found effective in degenerative arthritis, pain syndrome and
inflammatory joint disorders. Sleep disturbances often contribute
to increased pain perception. The QRS has also been found to
improve sleep. 68% report good/very good results. Even after
one year follow-up, 85% claim a continuing benefit in pain reduction.
Medication consumption decreases from 39% at 8 weeks to 88% after
8 weeks.
Even strengths lower than
the QRS may also treat knee pain in osteoarthritis. Treatment
for eight 6-min sessions over a 2-wk period may give a 46% decrease
in pain vs. an average 8% in the placebo group, sustained at
the same level even two weeks after treatment.
A 50 Hz pulsed magnetic
field sinusoidal, 0.035 Tesla field PEMF for 15 min for 15 treatment
sessions improves hip arthritis pain in 86% of patients. Average
mobility without pain improved markedly.
Post-traumatic Sudeck-Leriche
syndrome (late stage reflex sympathetic dystrophy - RSD) is very
painful pain and largely untreatable by other approaches. Ten
30-minute PEMF sessions of 50 Hz followed by a further 10 sessions
at 100 Hz plus physiotherapy and medication reduced edema and
pain at 10 days. There is no further improvement at 20 days.
Neuropathic pain syndrome
(NPS) patients benefit from pulsed radiofrequency (PRF) treatment.
Patients with severe left-sided sciatica and back pain, neuropathic
pain in the anterior chest wall had been taking oral medications
and had received repeated injections of local anesthetic agents
and steroids with poor results. The patients treated with an
invasive PRF applied to the related lumbar dorsal root ganglion
for 2 minutes or the spinal roots of the thoracic T2-T4 dermatomes
experience significant pain relief.
Even chronic musculoskeletal
pain treated with MFs for only three days, once per day can eliminate
and/or maintain chronic musculoskeletal pain.
A static magnetic foil
placed in a molded insole for the relief of heel pain was used
for 4 weeks to treat heel pain. 60% of patients in the treatment
and sham groups reported improvement. There was no significant
difference in the improvement on a foot function index. A molded
insole alone was effective after 4 weeks. The magnetic foil offered
no advantage over the plain insole, in this study. This study
like others with low numbers of patients, may not have had a
large enough sample. Placebo reactions in pain studies can be
large and differences in benefit may be harder to detect. In
addition, since magnetic foils produce fairly weak fields, placement
against tissue becomes important, as does consideration of the
depth into the body of the target lesion or tissue. Magnetic
fields drop off in strength very rapidly from the surface.
Even small, battery-operated
PEMF devices with very weak field strengths have been benefit
musculoskeletal disorders. Because of the low strength used treatment
at the site of pain may need to last between 11 to 132 days,
between 2 times per week, 4 hours each or, if needed, continuous
use. Use at night could be near the head, e.g., beneath the pillow,
to facilitate sleep. Pain scale scores are significantly better
in the majority of cases. Conditions that can be considered are
arthritis, lupus erythematosus, chronic neck pain, epicondylitis,
femoropatellar degeneration, fracture of the lower leg and Sudeck's
atrophy.
Musculoskeletal ailments
may be also be treated solely using a broad band very low strength
PEMF mattress-like device (QRS). Diagnoses may include intervertebral
disc prolapse, spinal stenosis and osteoporosis. Only 20 sessions
of 8 minutes, twice daily for two weeks help. Pain and forward
bending ability improve. Longer term use would be expected to
give even greater benefit.
240 patients treated with
PEMFs in a conservative orthopedic practice had decreased pain,
increased functionality and increased point pressure thresholds,
disappearance of swelling and pathological skin coloration, less
need for orthopedic devices and less reaction to changes in the
weather. Treatments are daily for an hour. Conditions treated
are: rheumatic illnesses, delayed healing process in bones and
pseudo-arthritis, including those with infections, fractures,
aseptic necrosis, loosened protheses, venous and arterial circulation,
reflex sympathetic dystrophy all stages, osteo-chondritis dissecans,
osteomyelitis and sprains and strains and bruises. The success
rate approaches 80%. Even X-rays may show improvement. cartilage/bone
tissue may reform, including the joint margin. About 60% of loosened
hip protheses have subjective relief of pain and walk better,
without a cane. Perthes' disease rarely completely reforms the
articular head of the hip.
Summary
PEMFs of various kinds
and strengths have been found to have good results in a wide
array of painful conditions. There is little risk when compared
to the potential invasiveness of other therapies and the risk
of toxicity, addiction and complications from medications. Clearly
more research is needed to elaborate mechanisms and optimal treatment
parameters. Many studies that have been reported here have been
controlled trials and many have been double blind placebo. Medical
practitioners are becoming gradually aware of the potential of
MFs to successfully treat or significantly benefit the myriad
of problems presented to them.