top of page

The effects of caregiver-supervised, home use of electromyographically-triggered electric stimulation on active dorsiflexion ROM of the ankle in children with spastic, diplegic cerebral palsy: a pilot study. [click for complete article of study] 

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 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 (>5?V) 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 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 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. 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. 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. Research Center, Vienna, Austria. Electromyogr. Clin. Neurophysiology 


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. 
For further information see Frequently Asked Questions

bottom of page