EMG Training Research Articles

NEUROFEEDBACK AND EMG TRAINING COMBINING EFFICIENCY STUDY IN 6–9 YEARS OLD ADHD CHILDREN

The research goal was to study neurofeedback and EMG combining training efficiency in ADHD children.To achieve the goal three groups were compared before and after training and six months later. Experimental group included ADHD children 6–9 years old. It was divided into two: group A trained thetabeta ratio and muscle tension decrease simultaneously while group B trained only theta-beta ratio decrease. Control group included healthy children. The results showed significant effect of combined EEG and EMG training for self-control improvement, anxiety and muscle tension decrease in comparison with standard EEG training.

Rehabilitation of Childrenwith Dysontogenetic-Dystrophic Syndrome for Combined Pelvicand Spinal Deformities

Objective. To analyze the effectiveness of complex remedial measures including biological feedback to pelvic girdle and spinal muscles in treatment of scoliosis in children with dysontogenetic- dystrophic syndrome. Material and Methods. The study included 49 patients aged 6 to 16 years with combined deformities of the pelvis and the spine (grade I and II measured by Cobb method). All examined patients had S-shaped scoliosis and pelvic asymmetry. The treatment included application of biological feedback after EMG training of patients. Results. The study showed that one of the basic requirements for successful EMG biofeedback application is a functional biocontrol. Patients are trained to control the activity of muscles and muscle groups, which are under disturbed or lost voluntary control. Functional biocontrol assumes using activity of the disturbed motor system itself. Biofeedback looping provides learning and fixation of motor patterns and a new behavior strategy allowing for voluntary correction of the disturbed motor functions. Conclusion. The application of EMG biofeedback to pelvic girdle muscles resulted in reduction or reversal of scoliotic deformity in the thoracic and lumbar spine. Formation of new statodynamic system decreased trunk and spinal muscle imbalance, and changed the direction of spinal curves.

Clinical neurophysiology training and certification in the United States: 2000

To the Editor: Burns et al. reviewed clinical neurophysiology (CNP) training in the United States.1 Since the approval of CNP as an added qualification examination and the establishment of CNP fellowships, EMG and EEG training have changed. We agree that there is limited exposure to CNP during residency and that additional training is often required. However, as currently structured, we believe CNP training has become too diluted, creating CNP generalists rather than focused experts, as was the case formerly. Burns et al. acknowledge that CNP training is not designed to make experts in each CNP area, but rather provides greater knowledge and skill than obtained during residency. One might ask where future EMG and EEG experts will come from, if not from CNP fellowships. The majority of residents pursuing fellowship training still do so in preparation for an academic career.2 It would appear unlikely that many candidates will opt for training beyond one additional fellowship year. We have had the opportunity to train fellows in 6-month, 12-month, and 2-year programs devoted solely to EMG/neuromuscular disorders. The largest growth in expertise occurs between 6 and 12 months, when fellows consolidate their knowledge, increase their confidence and procedural skills, and solve difficult problems independently. As currently structured, EMG training is particularly handicapped in CNP fellowships, because the equivalent of 12 months EMG training cannot …

ELECTRODE PLACEMENT IS NOT RESPONSIBLE FOR THE DIVERGENT INCREASES IN EMG AND FORCE WITH STRENGTH TRAINING

Some strength training studies with the first dorsal interosseus muscle (FDI) have failed to show parallel increases in EMG and force (Keen et al, JAP 77:2648, 1994; Laidlaw et al, JAP 87: 1786, 1999). To determine whether the placement of the surface electrodes in relation to the innervation zone was responsible for the non-parallel increases in EMG and force, four young adults (29 ± 2yrs, 2 males and 2 females) underwent strength training of the FDI for 4 weeks. Training was performed three times per week and each participant performed 6 sets of 10 repetitions of 80% 1-RM load. Strength was assessed with an isometric maximum voluntary contraction (MVC) and a one repetition maximum (1 RM). The EMG of the left FDI was measured using two pairs of bipolar surface electrodes (4 mm in diameter, silver-silver chloride). The first pair was secured over the innervation zone of the FDI, whereas the second pair of electrodes was placed at the distal end of the muscle. MVC force increased by 26.1% (9.2 ± 8.4 N) and 1-RM load by 55.3% (941.6 ± 420.9 g). The peak EMG amplitude recorded during the MVC from the distal pair of electrodes (891.0 ± 175.6 μV) was significantly greater than the EMG recorded from the pair of electrodes placed over the innervation zone (676.7 ± 154.7 μV). Similarly, the integrated EMG recorded during the 1 RM was greater for the distal pair of electrodes (1727.8 ± 448.2 μV's vs. 1371.1 ± 349.0 μV's). The EMG from both pairs of electrodes varied similarly over the four weeks of training. This change in EMG, however, did not parallel the increase in MVC force or 1-RM load. These results suggest that electrode placement was not responsible for the non-parallel increases in EMG with force during strength training. Supported by NIH award AG-09000 to RME.

Comparison of Alpha-Theta, Alpha and EMG Neurofeedback in the Production of Alpha-Theta Crossover and the Occurrence of Visualizations

Abstract Background: Alpha-theta biofeedback training has been employed in clinical addictions treatment since the first reports of successful application by Peniston and Kulkosky. Several studies have questioned the theta crossover component of this feedback protocol as necessary to the training condition. Methods: We observed theta and alpha amplitudes, percentage of theta/alpha crossover, and self-reports of visualization in 191 sessions of three different protocols of brain wave biofeedback. Feedback conditions studied were alpha only, alpha-theta, and a type of EMG training. Subjects with identical electrode placement in all conditions, and not informed as to the nature of the feedback received, were given the same induction and expectations. They were asked to describe imagery occurring during feedback. Results: Visualization was found to be not exclusive to alpha-theta neurofeedback, but instead was present in all three modes of feedback. In addition, an inverse relationship was found to exist betw...

Treatment of eczema by EMG biofeedback and relaxation training: A multiple baseline analysis

Five adults who suffered from eczema for at least five years were treated in a multiple baseline design with EMG biofeedback and progressive relaxation. Treatment consisted of five weekly EMG training sessions combined with regular home practice of relaxation. Three dependent measures were used to assess treatment effects: (1) daily self-monitoring of symptom irritation levels, (2) pre and post assessments of eczema affected areas and (3) the Spielberger Trait Anxiety Questionnaire which was also administered on a pre-post basis. Results showed clinically meaningful improvements in all five participants which were maintained at a two month follow-up. A second follow-up two years later showed that three of subjects were asymptomatic. The other two subjects could not be located. Taken together, the study provides evidence that EMG biofeedback combined with home practice of progressive relaxation can help to reduce the severity of eczema and the irritation associated with the disorder.

Task performance and electromyopotential as functions of task difficulty and EMG feedback.

The dearth of empirical research in the application of biofeedback is discussed. Exp. 1 assessed relationships among biofeedback EMG training, EMG levels, cognitive task performance, and task difficulty. 72 subjects (male or female college students) were administered 1 trial on an iconic memory task with either EMG audio feedback, sham EMG audio feedback, or no feedback. Three levels of task difficulty were used. One 20-min. training session significantly lowered EMG responses, and task performance was inversely related to task difficulty. No relationship between EMG level and task performance was observed. Exp. 2 investigated the effect of increased EMG responses on cognitive task performance for one level of difficulty. One biofeedback training session did not significantly increase frontalis EMG, and there was no relationship between increased EMG and task performance.

EMG biofeedback, attained relaxation and hypnotic susceptibility: is there a relationship?

Abstract Subjects low in hypnotic susceptibility were assigned to three treatments. Those in one group received two EMG biofeedback training sessions and were post-tested for susceptibility at the end of their second training session (i.e., while still experiencing high levels of training induced relaxation). Those in a second group also received two EMG training sessions but were posttested for susceptibility in a separate session. Controls were posttested without intervening training. None of the groups showed significant baseline to posttest increments in susceptibility. Nevertheless, subjects in the two training groups showed significant decrements in muscle tension and significant increments in rated relaxation across the training sessions. Moreover, subjects posttested at the end of their training session began hypnotic posttesting with significantly lower muscle tension and significantly higher rated relaxation than subjects in the other two groups. Contrary to the relaxation hypothesis muscle tens...

Predictors of success in the EMG biofeedback training of hyperactive male children.

EMG biofeedback training is continuing to evolve as a promising treatment of hyperactivity. But while research on its application suggests that this technique induces significantly lower EMG levels in experimental samples as a whole, it also discloses that some children evidence but limited reductions. Most likely, this variability is introduced by differences in subject attributes. This study assessed that prospect by examining whether four common subject characteristics correlated with the extent of decrease in EMG level achieved by 59 hyperactive school-aged boys. Those variables were pretreatment EMG level, age degree of hyperactivity, and locus of control. Number of applications or training sessions was included as the fifth predictor. A multiple regression analysis determined that only locus of control was predictive of success in EMG training; however, it accounted for 72% of the variance. Implications of these findings are discussed.

Effects of noncontingent feedback on EMG training, EMG responses, and subjective experience.

Various types of noncontingent feedback have been used as control procedures in EMG training; however, their effects on such training have received little attention. Experiment 1 in the present study examined the effects of noncontingent feedback on EMG training, and Experiment 2 assessed the effects of feedback characteristics on EMG responses. In Experiment 1, three noncontingent feedback groups (yoked control, randomly fluctuating tones, and decreasing tones) and one contingent group underwent 20 minutes of training for frontal EMG decreases. Procedures in Experiment 2 were identical to those in Experiment 1 except that subjects were instructed merely to listen to the feedback tones. Results of Experiment 1 indicated that contingent and noncontingent fluctuating feedback groups achieved significantly lower EMG levels than noncontingent decreasing and yoked control groups. In Experiment 2, however, no differences in EMG activity were found among groups. In both experiments, groups did not differ in terms of subjective variables such as frustration, suspiciousness about the tone, or length of time attending to the tone. Results of these two experiments suggest that differences in EMG responses to various types of noncontingent feedback result from interactions between characteristics of the feedback stimulus and instructions to decrease the stimulus.

Pulmonary changes induced by frontal EMG training

Earlier research suggested that the effects of facial muscle tension changes on other responses are not widespread but limited to a rather narrow set of pulmonary events. Further evidence in support of the specificity of the facial muscle-pulmonary relationship was provided in the present study by monitoring changes in several responses as a function of muscle tension training. Feedback training for increases and decreases in muscle tension at both facial and limb muscle sites was given to adult males. The effects of these manipulations on PEFR, RR, and HR were examined. Increases in facial muscle tension resulted in PEFR decreases whereas increases in limb muscle tension did not. Decreases in facial muscle tension were not observed as a function of training and no PEFR changes resulted from these conditions. Neither RR nor HR were related to the facial EMG changes observed during feedback training. These observations demonstrated the specificity inherent in the relationship between facial muscle tension and PEFR. and lent support to the hypothesis that these two responses are linked reflexively.

Subject expectancy effects in frontal EMG conditioning

The influence of subject expectancies on performance has been examined extensively within the framework of behavior therapy but has received little attention within the context of EMG training. This study assessed the effects of subject expectancy on acquisition during frontal EMG conditioning. Prior to conditioning, subjects were either given no expectancy or instructed that learning to control the feedback stimulus would be either easy (high expectancy) or difficult (low expectancy). Subjects in the three expectancy conditions then underwent 20 min of contingent reinforcement for frontal EMG decreases. Three similar groups of no, low, or high expectancy subjects received noncontingent reinforcement. Differential EMG behavior was exhibited between the two no-expectancy groups, with the contingent group reliably lower in EMG activity than the noncontingent. However, differences were not observed between contingent and noncontingent subjects given either low or high expectancy sets. None of the groups could be differentiated on the basis of subjective variables such as anxiety, relaxation, or frustration. These findings suggest that subject expectancies, either positive or negative, interfere with the acquisition of conditioned EMG behavior.

Biofeedback applications to migraine and tension headaches: A double-blinded outcome study

The efficacy of progressive relaxation, fingertip temperature training, and EMG training of the frontalis muscles was tested against chronic migraine and tension headaches in a double-blinded 3 X 2 design. All 56 subjects reported being conditioned in the course of the nine 1/2-hour training sessions. Detailed records of perceived severity and duration of the headaches were maintained by the subjects before the study and for at least 3 months after the training period. While even a conservative F revealed a diminution of perceived severity, of hours/month of headache, and of an index conceived by Budzynski, Stoyva, Adler, and Mullaney (1973), across time, at beyond the .05 level of significance, no specific treatment emerged as clearly most effective for either type of headache. Over time, however, progressive relaxation was not as good as the other procedures in reducing the number of hours/month of headache.

Cognitive self-control factors in EMG biofeedback.

This study investigated the efficacy of manipulation of cognitive self-control expectancy in EMG biofeedback training. It was predicted that a treatment procedure, which includes a positive-cognitive stage that establishes and reinforces a positive self-control belief system and also includes a training stage in EMG biofeedback, will be more effective in achieving a reduction in EMG activity than a treatment procedure which includes a negative-cognitive stage and which also includes ambiguous features prior to training and a treatment approach solely concerned with training. The study consisted of four groups with 10 subjects in each. In one group, expectation for inner control ability was created prior to actual training in reducing EMG activity. In the second group, expectation for negative self-control ability was created prior to EMG training. The third group only underwent the actual training in EMG. The fourth group served as a control group. The results show that the positive-cognitive self-control group was significantly more effective in reducing muscle activity than the other groups.

The protractor as a dependent measure of EMG training.

The protractor as a dependent measure of EMG training.

A comparison of skin temperature and EMG training for primary dysmenorrhea

Eleven female volunteers completed a 6-month treatment program consisting of a 2-month baseline phase, 2 months of biofeedback training (X number of sessions = 12.9), and 2 months of follow-up data collection. Subjects were assigned to one of two treatment groups: skin temperature training or EMG training of the frontalis muscle. Self-report data were gathered by means of the Symptom Severity Scale. Results, which were analyzed according to a 2 X 3 (treatment X phase) split-plot factorial design, indicate a highly significant overall treatment effect (F = 19.32 p less than .001). There was no significant difference between treatments (F = .47) and no significant interaction effect (F = 1.74).

Effectiveness of frontalis feedback training in producing general body relaxation

Although it is common for EMG frontalis feedback to be used to train general relaxation, there is a growing literature that challenges its use. This experiment explored whether successful frontalis EMG training produces concomitant covariation of autonomic nervous system indicators of decreased arousal and tension for highly anxious subjects. Twenty-four subjects were divided into groups receiving either frontalis feedback training, motivated constant-tone control, or motivated self-relaxation control procedures. Analysis showed that feedback training led to significantly lower frontalis levels, but similar effects were not found for heart rate, skin conductance levels, or respiration rate. The results suggest that even successful EMG frontalis feedback is not accompanied by anticipated reduction in related physiological descriptors. The use of frontalis tension level as an index of general tension is also discussed.

Generalization of conditioned muscle tension: a closer look.

ABSTRACTIn EMG biofeedback it has been suggested that covariation in tension levels between a trained and untrained muscle increases with continued training of the target muscle. Predictions of this sort are in contrast to the notion of response generalization which would predict decreased covariation between trained and untrained muscles with continued training. This study examined covariation between facial and forearm EMG levels during facial EMG biofeedback, and evaluated changes in such covariation which occurred with continued facial EMG training. Two groups of individuals were trained either to increase or to decrease facial muscle tension in 3 laboratory sessions during which simultaneous measures of facial and forearm EMG were obtained at 1‐min intervals. Comparison of facial EMG measures for these groups with those for a third, noncontingent control group revealed bidirectional conditioned effects for each training session. Some covariation between forearm and facial EMG was apparent for all groups. However, examination of change in covariation across sessions revealed that covariation decreased for groups receiving facial muscle training, whereas covariation levels exhibited by the noncontingent feedback group remained stable. This finding was consistent with the concept of response generalization but not with the notion of muscle tension generalization as employed in EMG biofeedback.

The effects of EMG feedback training during problem solving: a case study.

The present case study investigated the effects of competing task demands on biofeedback training to reduce frontalis muscle tension. Baseline levels of frontalis muscle tension were recorded for relaxation and problem solving. The subject was trained to decrease muscle tension with biofeedback for the problem-solving task alone. The results indicated that EMG training during problem-solving was successfully accomplished. Frontalis muscle tension during relaxation baseline did not change as a result of reductions in muscle tension during problem-solving feedback training. This suggests that the decrease of muscle tension cannot be attributed to reductions in overall muscle tension levels. Instead, training was specific to the problem-solving feedback phases. Additionally, it was found that accuracy in problem-solving did not decline as a result of simultaneous feedback training. Thus EMG biofeedback training can be accomplished and exercised without disruption of ongoing mental activity.