A preliminary analysis of EMG variance as an index of change in EMG biofeedback treatment of tension-type headache

The effectiveness of EMG biofeedback training for tension headache has been well established. Previous studies evaluating changes in an average EMG activity score from pre- to posttreatment have not consistently found a relationship between a reduction in average EMG activity and headache improvement at posttreatment. The current study is a preliminary analysis of the utility of EMG variance as another possible mechanism of change. Frontalis EMG average activity and variances from 6 chronic tension-type headache sufferers who demonstrated significant improvement in headache activity at posttreatment (at least 70%) and 6 chronic tension-type headache sufferers who did not demonstrate improvement (less than 30%) were examined across 6 sessions of biofeedback treatment. The improved group demonstrated larger time-specific EMG variance in relation to mean EMG amplitudes during all treatment sessions. A dramatic decline in time-specific variance was observed during the later treatment sessions for improved participants; this pattern was not observed in the group who demonstrated little or no improvement. Results from the current study suggest that the inclusion of both average EMG activity and EMG variance may provide a more comprehensive measure to evaluate possible physiological changes responsible for improvement in headache activity following EMG biofeedback training.     

Variations in digital temperature during frontal EMG biofeedback training in normal subjects

During frontal EMG biofeedback training, the relationship between frontal EMG and digital skin temperature was investigated in two experiments, which varied the number of baseline and feedback sessions. The results of Experiment 1 suggested a general relaxation effect, where digital temperature increased as frontal EMG decreased, especially for subjects with initially low hand temperature. Experiment 2 extended the number of baseline and feedback sessions and qualified the results of Experiment 1. EMG and digital temperature did not simultaneously converge toward general relaxation over the extended baseline or feedback sessions in Experiment 2. Furthermore, when the feedback signal was introduced, digital temperature dropped quickly but recovered to baseline levels within three feedback sessions; this drop in digital temperature was interpreted within the context of attentional demands of the biofeedback task. The results appeared consistent with the view that frontal biofeedback training teaches a discriminative skill of lower frontal EMG, and that this skill does not readily generalize to digital skin temperature.This research was supported by Grant 2 S06RR08038-17 funded by the National Institutes of Mental Health.     

Variations in digital temperature during frontal EMG biofeedback training in normal subjects

During frontal EMG biofeedback training, the relationship between frontal EMG and digital skin temperature was investigated in two experiments, which varied the number of baseline and feedback sessions. The results of Experiment 1 suggested a "general relaxation effect," where digital temperature increased as frontal EMG decreased, especially for subjects with initially low hand temperature. Experiment 2 extended the number of baseline and feedback sessions and qualified the results of Experiment 1. EMG and digital temperature did not simultaneously converge toward general relaxation over the extended baseline or feedback sessions in Experiment 2. Furthermore, when the feedback signal was introduced, digital temperature dropped quickly but recovered to baseline levels within three feedback sessions; this drop in digital temperature was interpreted within the context of attentional demands of the biofeedback task. The results appeared consistent with the view that frontal biofeedback training teaches a discriminative skill of lower frontal EMG, and that this skill does not readily generalize to digital skin temperature.     

Effect of therapist's active presence on EMG biofeedback training of headache patients

Sixteen patients suffering from tension or mixed headaches participated in a frontalis EMG treatment schedule of 15 sessions where the therapist was either actively present or almost completely absent. The aim of this study was to evaluate the impact of the therapist's active presence on the subject's ability to lower the EMG level. The active presence of the therapist consistently led to higher frontalis EMG level than that during the therapist's absence. Data also show that the EMG feedback administered was apparently effective in reducing subjective headache intensity along with EMG levels. The findings raise the question of an optimal dosage of presence and activity of the therapist during EMG feedback training.     

EMG biofeedback treatment of torticollis: A controlled outcome study

Successful treatment of torticollis with electromyographic (EMG) biofeedback has been reported in a number of single case and single group studies. The present investigation represents the first controlled outcome study. Twelve torticollis patients were randomly assigned to EMG biofeedback or relaxation training and graded neck exercises (RGP). The procedure involved three sessions of baseline assessment, 15 sessions of EMG BF or RGP, 6 sessions of EMG BF or RGP plus home-management, 6 sessions of home-management alone, and follow-up 3 months after the end of treatment. A variety of outcome measures were used including physiological (EMG from the two sternocleidomastoid muscles, skin conductance level), behavioral (angle of head deviation, range of movement of the head), and self-report (depression, functional disability, body concept), therapist and significant other reports and independent observer assessment of videos. In both groups, neck muscle activity was reduced from pre- to posttreatment. This reduction was greater in the EMG biofeedback group. There was evidence of feedback-specific neck muscle relaxation in the EMG biofeedback group. Therefore, the outcome was not due to nonspecific factors and could be attributed to feedback-specific effects. Changes in skin conductance level showed that neck muscle relaxation was not simply mediated by a general reduction of arousal. Significant improvements of extent of head deviation, and range of movement of the head, as well as reductions of depression were present, which were not different in the two groups. At the end of treatment, no patient was asymptomatic. Any therapeutic benefit was generally maintained at follow-up. The results and the procedural simplicity of RGP make the issue of cost-efficacy of EMG biofeedback a pertinent one. Further controlled outcome studies of EMG biofeedback treatment of torticollis with larger samples are required.This work was funded by grants from the Medical Research Council and the Dystonia Society.     

The response of manual motor functioning in Parkinsonians to frontal EMG biofeedback and progressive relaxation

The purpose of the current investigation was to determine the effects of frontal EMG biofeedback and progressive relaxation training on manual motor functioning in Parkinsonians. Twenty patients were matched and randomly assigned to two groups. All subjects were administered a brief manual motor assessment. The experimental group then underwent weekly sessions of frontal EMG and relaxation training for a period of 15 weeks. At the conclusion of the training period, both experimental and control groups were again administered the manual motor tasks. The results indicated that Parkinsonian patients are capable of significantly lowering frontal EMG activity levels. The motor task results, however, yielded no statistically significant differences between the two groups as a result of the biofeedback training.     

The effect of frontal EMG biofeedback training on the behavior of children with activity-level problems

N=1 withdrawal designs were employed with three children evidencing activity-level problems. Tutoring sessions occurred daily over a 2 1/2-month period. Each child was reinforced for decreasing frontalis muscle tension during auditory feedback while working arithmetic problems. Feedback was faded while tension reduction reinforcement was maintained. These procedures were repeated with reinforcement for increasing, rather than decreasing, muscle tension. Frontal EMG level, percent time on task, and motoric activity rate were obtained during sessions. Parent ratings of problem behavior in the home were recorded daily. Biofeedback with reinforcement was effective in both raising and lowering muscle tension. Effects were maintained by reinforcement. Results suggest a direct relationship between tension and activity levels. Academic performance and problem behavior improved significantly with reductions in EMG activity, although individual exceptions to these findings were present. Results lend support to the efficacy of frontal EMG biofeedback training in reducing activity, increasing attention to an academic task, and reducing problem behaviors.     

The effects of frontal EMG biofeedback and progressive relaxation upon hyperactivity and its behavioral concomitants

Hyperactive children (N = 15) and nonhyperactive children (N = 15) were compared. Hyperactive children were found to possess significantly higher (p less than .002) muscular tension levels and, in addition, presented more behavioral problems and had lower test scores. Both electromyographic (EMG) biofeedback and progressive relaxation exercises were successful in the significant reduction of muscular tension, hyperactivity, distractability, irritability, impulsivity, explosiveness, aggressivity, and emotionality in hyperactive children. The greatest improvement was seen in the area of "emotionality-aggression" (irritability, explosiveness, impulsivity, low frustration tolerance, aggresion). No differences were seen in the EMG improvement of drug and nondrug hyperactive children; both made progress under these self-control techniques. However, nondrug children made greater improvements in the behavioral area. Both EMG biofeedback and progressive relaxation resulted in improvements on the test scores of hyperactive subjects (Bender-Gestalt, Visual Sequential Memory, Digit Span, Coding). The therapy would appear to be improved by the inclusion of mental relaxation, concentration, meditation, and mind-blanking exercises for mental control.     

The effects of frontal EMG biofeedback and progressive relaxation upon hyperactivity and its behavioral concomitants

Hyperactive children(N=15) and nonhyperactive children(N=15) were compared. Hyperactive children were found to possess significantly higher(p < .002) muscular tension levels and, in addition, presented more behavioral problems and had lower test scores. Both electromyographic(EMG) biofeedback and progressive relaxation exercises were successful in the significant reduction of muscular tension, hyperactivity, distractability, irritability, impulsivity, explosiveness, aggressivity, and emotionality in hyperactive children. The greatest improvement was seen in the area of emotionality—aggression(irritability, explosiveness, impulsivity, low frustration tolerance, aggression). No differences were seen in the EMG improvement of drug and nondrug hyperactive children; both made progress under these self-control techniques. However, nondrug children made greater improvements in the behavioral area. Both EMG biofeedback and progressive relaxation resulted in improvements on the test scores of hyperactive subjects(Bender-Gestalt, Visual Sequential Memory, Digit Span, Coding). The therapy would appear to be improved by the inclusion of mental relaxation, concentration, meditation, and mind-blanking exercises for mental control.     

The role of EMG awareness in EMG biofeedback learning

Underlying most research on biofeedback learning is a theoretical model of the processes involved. The current study tested a prediction from the Awareness Model: High initial EMG awareness should facilitate response control during EMG biofeedback training. Seventy-two undergraduates were assessed for forehead EMG awareness by asking them to produce target responses from 1.0 to 5.0 µV every 15 s for 16 trials. Based on this assessment, two groups (high and low awareness) were trained for 64 trials to produce these target levels with either EMG biofeedback, practice (no feedback), or noncontingent EMG feedback. A transfer task was identical to the initial assessment. During training, the biofeedback group deviated less from target than the practice and noncontingent groups. The biofeedback group was the only group to improve from initial EMG awareness activity. During transfer, only the low awareness biofeedback group remained below initial EMG awareness level. These findings can be interpreted in terms of the Two-Process Model.     

Blood volume pulse biofeedback in the treatment of migraine headache: A controlled evaluation

In order to evaluate the specific effects of blood volume pulse (BVP) biofeedback in the treatment of migraine headaches, 21 female migraine patients were randomly assigned to one of three experimental conditions: temporal artery constriction feedback, temporal artery dilation feedback, or waiting list. Biofeedback training consisted of 15 sessions over an 8-week period. All patients completed 5 weeks of daily self-monitoring of headache activity and medication before and after treatment. Results showed that constriction and dilation biofeedback were equally effective in controlling migraines and produced greater benefits than the waiting-list condition. No significant relationships were found between therapeutic gains and BVP self-regulation skills. However, further analyses revealed that changes in headache activity and medication were associated with changes in vasomotor variability. The current rationale for the use of BVP biofeedback in the treatment of migraine is questioned and a new one is proposed.     

Blepharospasm: A case study comparison of trihexyphenidyl (Artane) versus EMG biofeedback

Blepharospasm is a chronic condition characterized by involuntary spasmodic closure of the eyelid(s). The present investigation empirically evaluated the relative efficacies of a current pharmacological and a psychological approach in the treatment of blepharospasm. An A-B-A-C-A single-case design was used to compare trihexyphenidyl [Artane] with EMG biofeedback. EMG activity in the frontalis muscle and number of eyeblinks were the dependent variables. The results indicated that Artane had no effect on either dependent measure and that biofeedback had a dramatic treatment effect on both dependent variables. Treatment gains were maintained at a 42-week follow-up. These results are discussed in light of the methodological considerations, the efficacy of psychological intervention, and the need for future research.     

Cognitive skills training versus EMG biofeedback in the treatment of tension headaches

In an effort to study the role of cognitive skills training in the treatment of psychosomatic disorders, two single-case design experiments were conducted to assess the relative effectiveness of biofeedback procedures and cognitive coping techniques in the alleviation of tension headaches. For both subjects, biofeedback training influenced mean frontalis EMG levels, although such changes were not associated with concomitant reductions in headache activity. It was the presence or absence of cognitive skills training, however, that determined whether each subject reported changes in headache levels. These results suggest that a more efficient treatment approach for tension headaches would involve an increased emphasis on the modification of maladaptive cognitive activity. The present findings support the general view that a comprehensive approach in the treatment of stress-related disorders requires a concomitant focus on the cognitive, behavioral, and affective dimensions of the symptom. It was also suggested that biofeedback technology may be a useful tool for studying the physiological consequences of particular cognitive processes and in identifying particular cognitions with anxiety-provoking properties.     

The treatment of cluster headache with relaxation and thermal biofeedback

Eleven patients with episodic cluster headache were assessed and offered a treatment program consisting of 8 weeks of training in abbreviated progressive relaxation followed by 12 sessions of thermal biofeedback. Four dropped out before treatment began. Of the seven who completed the full treatment regimen, three (27% of initial sample) reported some degree of improvement when their next cluster bout occurred. In no one was the disorder eliminated.This research was supported by a grant from the National Institute of Neurological and Communicative Disorders and Stroke, NS-15235.     

Generalization of EMG biofeedback training

Five young adults received audio biofeedback training to reduce trapezius EMG levels while they engaged in reading in an office, seated at a table. A multiple-baseline-across subjects design was employed in two separate studies. After training, all subjects demonstrated reduced EMG levels while reading in a home or library setting. The first study suggested that subjects reduced EMG levels by minimizing movements and altering their postures; the second study systematically demonstrated changes in such behavior, which was correlated with EMG levels. The data provide evidence that EMG biofeedback resulted in response generalization across several motoric classes, and in stimulus generalization from the training setting to the natural environment. The importance of assessing generalization is discussed.     

Generalization of EMG biofeedback training

Five young adults received audio biofeedback training to reduce trapezius EMG levels while they engaged in reading in an office, seated at a table. A multiple-baseline-across subjects design was employed in two separate studies. After training, all subjects demonstrated reduced EMG levels while reading in a home or library setting. The first study suggested that subjects reduced EMG levels by minimizing movements and altering their postures; the second study systematically demonstrated changes in such behavior, which was correlated with EMG levels. The data provide evidence that EMG biofeedback resulted in response generalization across several motoric classes, and in stimulus generalization from the training setting to the natural environment. The importance of assessing generalization is discussed.     

Blood volume pulse biofeedback treatment of chronic cluster headache

Behavioral interventions shown to be clinically effective in the treatment of migraine headache have generally not been employed for cluster headache. Herein, we report on the treatment of a severe case of chronic cluster headache with a common method of migraine treatment, temporal blood volume pulse (BVP) biofeedback. The patient was a 61-year-old male, medically diagnosed as suffering from chronic cluster headaches for over 20 years. Following an 18-day baseline, 14 BVP biofeedback sessions were conducted over a 7-week period. By the last 2 weeks of treatment, there was a 70% reduction in daily headache frequency and a 45% decrease in headache severity. Improvement was maintained at 1, 3, 6, 12, and 21 months follow-up. Large decreases in the consumption of migraine abortives, narcotic analgesics, and antiemetics were also observed. These encouraging results call for further evaluation of the efficacy of BVP biofeedback treatment of chronic cluster headache.This research was supported in part by the Psychological Services Center, Memphis State University. Portions of this article were presented at the meeting of the Society of Behavioral Medicine, Chicago, March 1982.