Electromyographic controlled neuromuscular electrical stimulation Scientific Articles and Abstracts.
Following is a selection of abstracts, articles and references,
including double blind placebo controlled, on electromyographic
controlled neuromuscular electrical stimulation (EMG triggered
NMES). This information has been collected to show the benefits on
the use of EMG triggered NMES. This technology is also referred to
under many different names.
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Questions
Techniques to Improve Function of the Arm and Hand in
Chronic Hemiplegia.
Summary: We evaluated functional
improvement in the upper limb of chronic (more than six months'
duration) stroke patients who received one of two electrical
stimulation treatments, conventional treatment, or no treatment.
Twenty-two right-handed patients were assigned to one of four groups
studied for 12 months post treatment. Subjects received (1)
EMG-initiated electrical stimulation of wrist extensors
(EMG-stimulation), (2) low-intensity electrical stimulation of wrist
extensors combined with voluntary contractions (B/B), (3)
proprioceptive neuromuscular facilitation (PNF) exercises, or (4) no
treatment. Subjects were treated for three months. Before treatment,
upon completion of treatment, and three and nine months after
treatment, subjects were evaluated by the Fugl-Meyer (FM)
post-stroke motor recovery test and by grip strength. Subjects also
attempted three Jebsen-Taylor hand function tests and a finger
tapping test at the same evaluation sessions, but many were unable
to complete these tests. During the course of treatment, FM scores
of subjects receiving PNF improved 18%, B/B improved 25%, and
EMG-stimulation improved 42%. The aggregate FM improvement of the
treated groups was significant from pre-treatment to post-treatment,
and the improvement was maintained at three-months and nine-months
follow-ups (all p<.005).the treated subjects' improvement in grip
strength was also maintained at both follow-ups (p, .10). In
contrast, the control group showed no significant change in FM
scores or grip strength. The four treated subjects who were able to
perform the hand function tests and finger tapping at all four
evaluations also improved on these tests. We conclude that
chronic stroke patients can achieve and maintain functional
improvements, especially by combining electrical stimulation
techniques with voluntary effort.
George H.
Kraft MD et.al. Arch Phys Med Rehabilitation
Electromyographically triggered electric muscle
stimulation for chronic hemiplegia.
Electromyographically triggered electric muscle
stimulation (EMS) was evaluated in combination with conventional
treatment in 69 consecutive post-cerebrovascular accident
outpatients whose onset of hemiplegia was four months to 14 years
earlier. Six subjects initially exhibited no residual volitional
activity in targeted muscles, and all patients had undergone
conventional therapy with little or no functional recovery.
Prescribed treatment (patient compliance was frequently substandard)
involved several months of four to five sessions per week, focusing
on wrist extension and/or ankle dorsiflexion initially and often
other movements later. During 30 to 300 movement attempts per
session, EMG's that exceeded a preset threshold triggered immediate
stimulation to force movement completion. Over sessions, patients
commonly realized substantially improved increases in voluntary EMG
capabilities generally proportionate to the frequency of treatment
sessions. Parallel improvements were also found for subjectively
scaled functional measures of range-of-motion and ambulation.
Motivation was important to success, but side and nature of stroke,
age, and post-stroke interval were not. Progress often far exceeded
that of previous conventional therapy. Regarding mechanisms,
impaired proprioceptive feedback is considered central to
stroke-disrupted sensorimotor control. EMG-triggered EMS is intended
to improve brain relearning by reinstating proprioceptive feedback
time-locked to each attempted movement. Clinical results were
consistent with this theory.
R.W. Fields,
Arch. Phys. Med. Rehabilitation
Chronic
Motor Dysfunction After Stroke.
Summary: Recovering
Wrist and Finger Extension by Electromyography Triggered
Neuromuscular Stimulation. Background and Purpose: After stroke,
many individuals have chronic unilateral motor dysfunction in the
upper extremity that severely limits their functional movement
control. The purpose of this study was to determine the effect of
electromyography triggered neuromuscular electrical stimulation on
the wrist and finger extension muscles in individuals who had a
stroke >1 year earlier. Methods: Eleven individuals volunteered
to participate and were randomly assigned to either the
electromyography triggered neuromuscular stimulation experimental
group (7subjects) or the control group (4 subjects). After
completing a pre-test involving 5 motor capability tests, the
post-stroke subjects completed 12 treatment sessions (30 minutes
each) according to group assignments. Once the control subjects
completed 12 sessions attempting wrist and finger extension without
any external assistance and were post-tested, they were then given
12 sessions of the rehabilitation treatment. Result: The Box and
Block test and the force-generation task (sustained muscular
contraction) revealed significant findings (P<0.05). The
experimental group moved significantly more blocks and displayed a
higher isometric force impulse after the rehabilitation treatment.
Conclusions: Two lines of evidence clearly support the use of the
electromyography triggered neuromuscular electrical stimulation
treatment to rehabilitate wrist and finger extension movements of
hemiparetic individuals > year after stroke. The treatment
program decreased motor dysfunction and improved the motor
capabilities in this group of post-stroke individuals. J. Cauraugh, PhD. et. al. Journal Physiotherapy
Electromyogram Triggered Neuromuscular Stimulation
for Improving the Arm Function of Acute stroke Survivors: A
Randomized Pilot Study.
Objective: To assess the
efficacy of electromyogram (EMG)-triggered neuromuscular stimulation
(EMG-stimulation) in enhancing upper extremity motor and functional
recovery of acute stroke survivors. Design: A pilot randomized,
single-blinded clinical trial. Setting: Freestanding in-patient
rehabilitation facility. Patients: Nine subjects who were within 6
weeks of their first unifocal nonhemorrhagic stroke were randomly
assigned to either the EMG-stimulation (n=4) or control (n=5) group.
All subjects had a detectable EMG signal (>5µV) from the surface
of the paretic extensor carpi radialis and voluntary wrist of the
paretic extensor carpi radialis and voluntary wrist extension in
synergy or in isolation with muscle grade of <3/5. Intervention:
All subjects received two 30-minute sessions per say of wrist
strengthening exercises with EMG-stimulation (experimental) or
without (control) for the duration of their rehabilitation stay.
Main Outcome Measures: Upper extremity Fugl-Meyer motor assessment
and the feeding, grooming, and upper body dressing items of the
Functional Independence Measure (FIM) were assessed at study entry
and at discharge. Results: Subjects treated with EMG-stimulation
exhibited significantly greater gains in Fugl-Meyer (27.0 vs 10.4;
p=.05), and FIM (6.0 vs 3.4: p=.02) scores compared with controls.
Conclusion: Data suggest that EMG-stimulation enhances the arm
function of acute stroke survivors.
G.
Francisco, MD et.al OTR. Arch. Phys. Med. Rehabilitation
Mental
Practice of Motor Skills used in post-stroke Rehabilitation has Own
Effects on Central Nervous Activation.
In the last years
it has been shown that the use of the EMG triggered electrical
myostimulation (ETEM) brings good results in post-stroke
rehabilitation. It has been hypothesized that the relearning effects
obtained by means of ETEM are due to the reinstatement of
proprioceptive feedback. However, the technique is most powerful if
imagination of motor acts (the so called mental practice) is used as
an initial part of ETEM. Since mental practice in healthy people
leads to central nervous activation processes as well as to an
improvement of motor skills, we investigated the effects of mental
practice alone on central nervous activity by means of EEG in stroke
patients. Twelve left-sided hemiplegic patients who underwent a
specific post-stroke rehabilitation treatment were requested to
perform a simple arm movement sequence. In the following mental
practice period the patients were requested to imagine the same
sequence without any real movement. EEG background activity was
recorded during baseline and imagination periods. After the
calculation of z-transformed power values within the alpha and
beta-1 band, differences between rest and imagination periods were
evaluated for significance. Stroke patients showed significant
decreases of alpha as well as beta-1 power during mental practice in
comparison to the rest period. These changes are similar to those
obtained in healthy subjects. Central alpha power diminished only
during imagination of the contralateral arm. This phenomenon as well
as the decrease of beta-1 power in central derivation were also
obtained during real motor performance and might indicate an
activation of the sensorimotor cortex. In accordance with the
hypothesis of internal feedback mechanisms, this activation is a
necessary prerequisite for motor learning during mental practice. We
conclude that mental practice of motor skills might have own effects
in post-stroke rehabilitation.
T. Weiss et.al.
International J. Neuroscience
Treatment of Hemiplegia by Means of
Imagination-dependent EMG-triggered muscle stimulation.
Summary: The imagination of a movement elevates the
electrical activity of paralyzed muscles. By means of a device this
changed activity is used to generate low-frequency pulses which in
turn are applied to induce a contraction of the spastic antagonist
muscles. In this way the imagination-dependent muscle stimulation -
triggered by EMG - circumvents the spastic movement patterns. The
patient becomes able to regain forgotten movements by means of the
method described. During the acute phase after a stroke it was
applicable in only one third of our patients (n=40). Another group
consisted of out-patients (n=20). In 18 of these a functional
improvement of the paralyzed arm was attained after treatment for
six months.
J. Danz Physikalische Medizin
Rehabilitation of walking with electromyographic
biofeedback in foot-drop after stroke. Randomized controlled
Trial.
Background and purpose: Alterations of gait cycle
and foot-drop on the paretic limb are characteristic of stroke
patients. Electromyographic biofeedback treatment has been used in
rehabilitation of walking, but results are controversial. We
performed gait analysis to evaluate the efficacy of
electromyographic biofeedback compared with physical therapy.
Methods: Sixteen patients with ischemic stroke were enrolled in the
study. The experimental group (4 men, 4 women) received
electromyographic biofeedback treatment together with physical
therapy. The control group (5 men, 3 women) was treated with
physical therapy only. Clinical and functional evaluations before
and after treatment were performed using Canadian Neurological,
Adams, Ashworth, Basmajian and Barthel Index scales. Computerized
gait analysis was performed in all patients. Results:
Electromyographic biofeedback patients showed significantly
increased scores on the Adams scale (P < .05) and Basmajian scale
(P < .01). Gait analysis in this group showed a recovery of
foot-drop in the swing phase (P < .02) after training.
Conclusions: Our data confirm that the electromyographic biofeedback
technique increases muscle strength and improves recovery of
functional locomotion in patients with hemiparesis and foot-drop
after cerebral ischemia.
Intiso D. et.al.
Rehabilitation Center, IRCCS, Rome, Italy. Journal: Stroke
Feedback of ankle joint angle and soleus
electromyography in the rehabilitation of hemiplegic gait.
A computer-assisted feedback system was developed to
present to walking subjects instantaneous feedback of their muscle
activity or joint angular excursions during gait. Targets for muscle
activity or joint motion were displayed on the feedback screen along
with timing cues that prompted muscle activity or joint
flexion/extension at specific times during the gait cycle. The
purpose was to compare the effectiveness of joint angle and
electromyographic (EMG) feedback to a focused program of physical
therapy for gait. Eight hemiplegic stroke patients were treated with
ankle joint angle feedback, EMG biofeedback from the soleus muscle,
and conventional physical therapy for gait in a three-period
crossover design. PT was given either first or last in the sequence
of treatments. Gait analysis prior to and following each type of
treatment revealed that the feedback treatments resulted in
significant increases in stride length and walking velocity and in
positive changes in push-off impulse, gait symmetry, and standing
weight-bearing symmetry, as evaluated in a general linear model and
paired t-tests. Overall, physical therapy produced no significant
changes. However, when physical therapy was the first treatment of
the sequence, significant increases in stride length and velocity
were observed. When physical therapy was last, there were
significant negative changes in gait symmetry and standing
weight-bearing symmetry, and negative trends in stride length,
walking velocity, and push-off impulse. It is concluded that
computer-assisted feedback is an effective tool for retraining gait
in stroke patients.
Colborne G.R. et.al.
Queen's University, Kingston, Canada Arch Phys Med
Rehabilitation
Myobiofeedback in motor re-education of wrist and
fingers after hemispherial stroke.
32 patients with
different grade of hemiparesis, were in the first weeks after a
cerebral vascular accident treated by means of EMG-feedback in
respect to volar and dorsal flexion of the wrist, flexion and
extension of the fingers, and opposition of thumb to the second ev.
other fingers. EMG was registered from suitable muscles of the
paretic limb. The attempt of volitional movement at the paretic side
was conditioned with a reinforced mirror synergia of the same type
from the healthy to the damaged side. The patient observed the
effect on the EMG screen. After 3-6 conditionings the patient
performed the volitional movement alone. In 25 of patients (e.g.
78.1%) improvement was obtained, at least in EMG. A good correlation
was found between effect of the procedures and severity of paresis
(p less than 0.05; chi 2 = 7.35).
Rathkolb O.
et.al. Research Center, Vienna, Austria. Electromyogr. Clin.
Neurophysiology
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