Relaxation training and biofeedback in the reduction of frontalis muscle tension

EMG—Induced Muscle Relaxation as a Treatment for Learning Disability: Efficacy yet to be Proven

Biofeedback procedures for stress reduction have been widely used in a variety of settings. While there are many reports of the successful application of EMG procedures for general tension-reduction with adults and children, little has been done concerning these procedures with children who suffer from a specific learning disability. The present paper reviews the use of EMG biofeedback with learning-disabled children and, after examining those studies performed to date concludes that the supportive conclusions drawn by previous authors can be criticised on methodological grounds, and that the issue of indirect treatment of learning disability via EMG biofeedback is open to discussion. Directions for future research are described.

Stress management techniques: are they all equivalent, or do they have specific effects?

This article evaluates the hypothesis that various stress management techniques have specific effects. Studies comparing various techniques are reviewed, as well as previous literature reviews evaluating the effects of individual techniques. There is evidence that cognitively oriented methods have specific cognitive effects, that specific autonomic effects result from autonomically oriented methods, and that specific muscular effects are produced by muscularly oriented methods. Muscle relaxation and/or EMG biofeedback have greater muscular effects and smaller autonomic effects than finger temperature biofeedback and/or autogenic training. EMG biofeedback produces greater effects on particular muscular groups than progressive relaxation, and thermal biofeedback has greater finger temperature effects than autogenic training. Disorders with a predominant muscular component (e.g., tension headaches) are treated more effectively by muscularly oriented methods, while disorders in which autonomic dysfunction predominates (e.g., hypertension, migraine headaches) are more effectively treated by techniques with a strong autonomic component. Anxiety and phobias tend to be most effectively treated by methods with both strong cognitive and behavioral components.

A "fair" comparison of progressive and imaginal relaxation

Progressive and imaginal relaxation-training procedures are difficult to compare because the latter takes many forms. In this study, an imaginal procedure was used that closely followed progressive operations except that muscle tension was imagined rather than experienced. The dependent variable was the total score on the Relaxation Inventory. College students were placed in groups (ns = 50) high and low on suggestibility based on scores on the Creative Imagination Scale, assigned in equal numbers to the imaginal and progressive relaxation conditions and given four sessions of relaxation training. The pre- and posttrials effects were significant within each of the four training sessions. There were no significant differences in reports of relaxation by the progressive and imaginal treatments. The expected cumulative effect of relaxation training across the four sessions was not found; in fact, the imaginal condition showed a significant decrease. The only significant suggestibility effect was an interaction between suggestibility and trials in which highly suggestible subjects reported less pre-session relaxation. These results are consistent with reports of no differences between progressive and imaginal relaxation training.

The use and utility of EMG biofeedback with chronic schizophrenic patients

This study examined the efficacy of muscle relaxation training via electromyographic (EMG) biofeedback from the frontalis and forearm extensor muscles of schizophrenic inpatients. Thirty chronically hospitalized patients were randomly assigned to one of three conditions: EMG biofeedback from the forearm extensor and frontalis muscles, progressive relaxation, and a control group. Treatment consisted of one session of orientation and baseline, and six sessions of training. The results indicated that the schizophrenic patients receiving EMG training had significantly lower EMG recordings than the progressive relaxation group, which, in turn, was significantly lower than the control group. Analyses of covariance on the Tension-Anxiety scale from the Profile of Mood States revealed no significant effects, while finger-tapping rates were significantly improved only for the arm receiving feedback training in the EMG group. On the Nurses Observation Scale for Inpatient Evaluation the biofeedback group significantly improved on the Social Competence and Social Interest factors.

Detection of noncontingent feedback in EMG biofeedback

Noncontingent feedback is frequently used as a placebo control procedure in biofeedback research. Researchers, however, have criticized this procedure for lacking credibility because of easy detection. The present study examined detection of false feedback in biofeedback with EMG. Contingent feedback (CF), truly random false feedback (FF), and controlled false feedback (CFF) groups were compared for changes in EMG levels, report of inaccurate feedback, and report of learning muscle activity reduction. The results indicated that FF procedures are easily detected; therefore, difference found between the FF and CF groups may be influenced by extraneous variables. The CFF group did not detect false feedback, but subjects reported some suspicions in later trials. With more trials, CFF may have also been detected. These results indicate a need for more attention to appropriate placebo control procedures in evaluating the parameters and efficacy of biofeedback.

Progressive relaxation as a function of procedural variations and anxiety level

Progressive relaxation is subject to many procedural variations. Although most investigators follow the 5-7 s tension interval advocated by Bernstein and Borkovec (1973), longer tension intervals may contribute to greater relaxation effects. This study compared tension intervals of 5, 15, and 45 s. Since the development of control over muscle tension requires attention to feedback signals, a focus on internal proprioceptive sensations was contrasted with an external condition in which the subjects silently subtracted numbers immediately following the tension-release cycle. Longer periods of tension resulted in lower EMG levels, with the 45-s tension interval producing the greatest relaxation. Those individuals who focused on physiological sensations during training were able to achieve greater levels of relaxation after the training phase was completed. There was a significant interaction between tension interval duration and focusing; subjects in the 45-s interval who focused on physiological functioning showed the greatest arousal reduction. Anxiety level did not differentially influence the effects of procedural variations in training. Clearly, additional parametric studies in relaxation training are needed.

Initial relaxation response: contrasts between clinical patients and normal volunteers

The effectiveness of EMG biofeedback, progressive muscle relaxation, autogenic training, and self-relaxation were compared using a within-subjects design. Thirteen clinical subjects and 48 normal volunteers participated in 4 counterbalanced relaxation sessions using one of the techniques. Frontalis EMG and surface skin temperature were monitored throughout the sessions. For reducing EMG, biofeedback was more effective than the other three techniques. A significant interaction of treatment X subjects was found for changes in skin temperature. Clinical subjects had the greatest increase in skin temperature with EMG biofeedback and analog subjects responded best to self-relaxation. There were no significant differences in initial measures of EMG or skin temperature for the two samples.

The role of awareness in the control of frontalis muscle activity

An experiment was conducted to evaluate whether awareness of change in frontalis muscle activity was necessary and sufficient for voluntary control over the muscle. Forty subjects were required to relax, tense and complete both a test of awareness and an isometric magnitude production task, using the frontalis muscle. Following the completion of these pre-training assessment procedures, one group of subjects underwent either: Training in muscular awareness; biofeedback training in muscular control; both awareness and muscular control training; or a non-training control procedure. Following training, all subjects were again evaluated using the pre-training assessment procedures. The results indicated that an increase in awareness was not sufficient to produce an increase in muscular control, nor was it necessary for an increase in the ability to tense the frontalis muscle. These results suggest that Brener's model of voluntary control needs to be re-examined.

EMG biofeedback with college student volunteers: limitations of effects of independent variables

In the present study the relative effects of biofeedback, a set to relax, and a no set (adaptation) condition upon EMG changes in the frontalis muscles were addressed. Subjects were college student volunteers and the proportion of males to females was equal among groups. All subjects were first monitored for minutes (adaptation, no set). Subsequently, subjects in the biofeedback group were then instructed to relax and also to attend to feedback signals to facilitate relaxation for 20 additional minutes (1-min. trials). Subjects in the relaxation set group were given a set to relax but not biofeedback until the last 5-min. segment. Subjects in the no set group were given no instructions to relax and no biofeedback until the last 5-min. segment. Results indicated reductions of EMG monitored tension levels in all groups with no significant between-group differences. Pre- and poststate anxiety self-report measures also showed a significant reduction in anxiety for all groups but no between-group differences reached significance.

A meta-analysis of frontalis EMG levels with biofeedback and alternative procedures

The lack of comparative reviews of the efficacy of EMG frontalis biofeedback versus alternative procedures for reduction of muscle tension prompted the present meta-analytic treatment of literature previously concluded to be "equivocal." Twenty studies comparing EMG frontalis biofeedback with other tension-reduction procedures produced a total of 68 separate effect sizes suitable for meta-analysis. Differences between "clinical" and "normal" samples were nonsignificant, and data analyses revealed that EMG frontalis biofeedback was significantly superior to control (p less than .05) but that alternative forms of muscle relaxation, while effective, did not reach statistical significance.

Single- and successive-site EMG training in responding to anticipated pain

In a comparison among relaxation procedures, 32 college students were assigned to four group of equal size. Electromyographic response training was given with biofeedback (EMG training) on the forehead (frontal area) alone, on the frontal area, neck (sternomastoid), and forearm areas in succession, or on these three sites in conjunction with recorded relaxation instructions used at home. Relative to a control group, which received no training, the three biofeedback-trained groups maintained lower EMG levels on the frontal and sternomastoid sites, and the group provided with the relaxation instructions plus EMG training showed lower skin conductance levels. These patterns were generally maintained during the presentation of a stimulus (stressor) that ostensibly signaled an impending electric shock. Other measures, including peripheral temperatures and self-reported anxiety, also showed effects consistent with the stressor presentations but did not differentiate the groups. The results are discussed in terms of common clinical relaxation procedures, an alternative procedure for training several sites simultaneously, and implications for models of EMG training and arousal.

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.

Treatment of substance abuse by relaxation training: a review of its rationale, efficacy and mechanisms

The efficacy of relaxation training as a treatment for alcohol and drug abuse is reviewed, and directions for future research derived. Such use of relaxation procedures, notably progressive muscular relaxation and meditation, has been widespread and is premised on the assumptions that substance abuse is causally linked to anxiety and that anxiety can be reduced by relaxation training. However, the evidence suggests that such precipitating anxiety is limited to interpersonal-stress situations involving diminished perceived personal control over the stressor, and that alcohol and other drugs are often consumed for their euphoric rather than tranquilizing effects. Consequently, the empirical support for the effectiveness of relaxation training as a treatment for substance abuse in general is equivocal. As well, the existing outcome studies suffer from numerous methodological and conceptual inadequacies. In cases of demonstrated effectiveness, increased perceived control is a more plausible explanation than is decreased anxiety.

Three recurring electromyographic biofeedback research problems and a laboratory model

Exp. I investigated three recurring problems in electromyographic (EMG) biofeedback research. (1) Pre-knowledge that research involved biofeedback resulted in a selective bias on the part of students asked to volunteer as subjects. (2) EMG readings were not affected by repeated use of the word relax in verbal instructions. (3) The forearm extensor was the only muscle group which showed a statistically significant effect after one 20-min. training session. Exp. II challenged and clarified results of Exp. I and concluded the study with an empirically derived laboratory model for EMG biofeedback research.

EMG levels in the occipitofrontalis muscles under an experimental stress condition

In view of the importance attached to the frontalis muscles by researchers into the etiology of head pain and its treatment by biofeedback techniques, it is surprising that no data have yet been reported on the functioning of the occipitalis muscles, which have a close physiological relationship to the frontales. This study explores the response of the frontalis and occipitalis muscles under a condition of experimental stress. Migraine and tension-headache sufferers were separately compared with a headache-free control group under four conditions: baseline, while listening to instructions, while carrying out an auditory vigilance task, and for a further resting period equivalent to baseline. Results showed that tension levels in the frontalis muscles were not elevated at rest in any of the experimental groups, nor were they significantly responsive to the experimental task. The occipitales however proved to have significantly higher levels in both the tension-headache and migraine groups during the task and recovery periods. The results for the tension group reached significance because of a drop in control group values. These results may have significance in determining the best site for electrode placement in biofeedback.

Controlled group designs in biofeedback research: ask, "What does the control group control for?"

The extant literature on the specific role of biofeedback in promoting skeletal muscular relaxation is reviewed and found deficient with respect to the use of properly controlled group outcome research. The review emphasizes the failure of commonly used control procedures to adequately control a number of potentially confounding variables. Strengths and weaknesses of three types of controlled group design (attention placebo, pseudofeedback, and altered contingency) are discussed with respect to their relative usefulness in controlling certain nonspecific or placebo effects in biofeedback research. Many published biofeedback studies failed to measure the credibility of control procedures or the subject's ability to discriminate different feedback contingencies. The studies reviewed suggest that the various control procedures used are not inert and are not equivalent with respect to their effects on control group behavior. The suggestion is made that the controlled group outcome design be accepted as the minimum requirement for testing the specific effects of biofeedback, and possible methods for improving control procedures are discussed.

Biofeedback efficacy studies: a critique of critiques

Biofeedback, a field still in its infancy, has developed treatments that have been used with clinical success in the treatment of a number of disorders. Many have expressed their public concern that biofeedback had not lived up to its early promise and that it has not developed treatments that are, in fact, efficacious. A number of factors, which are inherent in biofeedback research, confound the results of clinical efficacy studies of biofeedback treatments. Researchers interested in the efficacy of biofeedback must address several issue: (1) Rejecting the null hypothesis is not equal to proving the null hypothesis (without the use of power analysis); (2) control for nonspecific effects is not equal to a double-blind experimental design; (3) ignorance of a mechanism of action is not equal to a lack of clinical efficacy; (4) the administration of training is not equal to the subject's learning to criterion; (5) untrained therapists are not equal to trained therapists; (6) statistical significance is not equal to clinical significance; and (7) the laboratory setting is not equal to the clinical setting.

The effect of stress imagery on arousal and its implications for biofeedback of the frontalis muscles

The purpose of this study was to determine whether the frontal muscles of the forehead during the imagination of an individualized stress situation reflect general arousal. Physiological arousal and subjective feelings of tension were measured during a stress and a relaxing imaginative situation, utilizing a counterbalanced design. Frontalis EMG during stress imagination was raised and was paralleled by more reported tension, elevated skin conductance, and trends toward increments in heart rate and respiration rate. The raised frontalis EMG can be seen as a consequence of the greater effort spent in the stress imaginative situation than in the relaxing one. This experiment supports an important assumption of the clinical application of frontalis EMG biofeedback to stress-related disorders. Other assumptions still remain to be examined.

Effectiveness of EMG biofeedback training for controlling arousal in subsequent stressful situations

Thirty-five subjects participated in (1) a pretreatment session during which arousal was measured while subjects anticipated and then viewed a stressful film; (2) four 20-min treatment sessions during which subjects received either contingent EMG biofeedback (biofeedback treatment), instructions to attend to a variable pitch tone (attention-placebo control), instructions to relax as much as possible (instructions-only control), or instructions to sit quietly (no-treatment control); and (3) a posttreatment session that was identical to the pretreatment session. Results indicate that when compared to the subjects in the control conditions, subjects who received EMG biofeedback were not effective in reducing frontalis EMG levels during treatment or while viewing the stressful film, but they were effective in reducing frontalis EMG levels while anticipating the stressful film. There was no evidence that EMG biofeedback influenced either skin conductance or self-reports of arousal.

Changing measurement instrument at follow-up: a potential source of error

The purpose of this investigation was to determine whether headache activity information collected over the phone can be directly compared with headache activity information collected by systematic self-observation without jeopardizing internal validity because of calibration differences between the two measurement methods. A number of headache studies have relied on phone information for long-term follow-up data, while using systematic self-observation to collect all other data. Twenty-six headache sufferers participating in a tension headache study reported their headache activity over the phone and subsequently charted their headaches. Correlations were computed between the two measures. Results indicated that differences exist in the calibration of the two measurement methods. This seriously limits the conclusions of studies that used phone information to obtain follow-up data. Other recommendations concerning follow-up methodologies are discussed.

Frontal electromyographic feedback. Stress attenuation and generalization

This study evaluated the effects of one session of frontal electromyographic (EMG) feedback on (1) frontal EMG, (2) frontal EMG response to stress, (3) cardiovascular variables, and (4) cardiovascular responses to stress. Eighteen male and female undergraduate volunteers received either frontal EMG feedback or a relaxation instructions control procedure and were then exposed to a fear stimulus (visualization of a feared situation) and a post-stress adaptation period while several cardiovascular measures were monitored. In comparison to the control group, frontal EMG feedback significantly reduced resting levels of frontal EMG and frontal EMG response to stress but had no significant effect on cardiovascular measures. The results of this study suggest that one session of frontal EMG feedback may attenuate response to stress but, within the paradigm utilized, may be confined to the specific muscle groups monitored. Additional areas of needed research were noted including individual differences in generalization, the effects of EMG feedback from multiple sites sequentially and concomitantly, and the generalized effects from symptom-specific sites.

Heart rate and finger pulse amplitude during muscular relaxation with frontalis versus forearm EMG feedback

Twenty-nine volunteers participated in a one-session experiment consisting of 10 min rest followed by a 30 min treatment period. Brief relaxation instructions were given at the beginning of the rest period. The treatment was either frontalis EMG feedback, forearm EMG feedback, or non-contingent stimulation. The two feedback groups showed EMG decreases in their respective target muscles during the no-feedback rest period, with no further decrease during feedback training, indicating that feedback was no more effective than relaxation instructions. Heart rate decreased significantly in both feedback groups. Finger pulse amplitude decreased significantly in the forearm feedback group. It is pointed out that the latter change does not necessarily indicate peripheral vasoconstriction, but may be due to a fall in pulse pressure as a consequence of increased blood flow to the relaxing muscles. The results are unsupportive of the assumption that frontalis relaxation is particularly effective in inducing a generalized relaxation.

Effects of frontalis EMG feedback and reinforcement on frontalis EMG level

This experiment employed a between-subjects design (N = 40) to investigate the effects of feedback and reinforcement on the lowering of frontalis electromyographic (EMG) activity. The feedback and reinforcement manipulations were combined in a 2 x 2 factorial design and each subject underwent one baseline and two training sessions on three consecutive days. The analogue feedback signal was a 55 dB tone whose pitch varied as a function of EMG activity, while the reinforcement consisted of points which were exchangeable for money. The training sessions were each divided into 10 2-min baseline periods and 10 2-min trial periods. The results indicated that although analogue feedback did not result in lowered EMG levels, trial period EMG level was significantly lower than baseline level under conditions of reinforcement. These results pose problems for Budzynski and Stoyva's (1972) views concerning the therapeutic usefulness of frontalis EMG feedback training.

Biofeedback treatment of atopic dermatitis: controlled case studies of eight cases

To investigate the feasibility of a behaviorally oriented intervention program with atopic dermatitis, 12 patients were exposed to a fixed sequence of treatment phases including a no-treatment baseline phase, a phase incorporating nonspecific treatment factors, and a phase involving frontal electromyographic (EMG) feedback and relaxation instructions. Photographic analyses of involved skin areas revealed significant remission of dermatological problems across the entire program, although significant changes could not be attributable to any specific phase. Ratings of itching level decreased within but not across treatment sessions, and variable correlations across subjects were found between frontal EMG and itching level. MMPI results from the dermatitis subjects were within normal limits. Overall, the results provided mixed support for the hypothesis that atopic dermatitis may be amenable to intervention through behaviorally oriented treatment procedures.

The relative effectiveness of three techniques to induce the trophotropic response

The purpose of this study was to examine the relative effectiveness of electromyographic biofeedback training (EMG BFT), meditation, and progressive muscle relaxation (PMR) in eliciting a relaxation or trophotropic response as measured by frontalis muscle tension, heart rate, electrodermal response, respiration rate, and skin temperature. Fifty-four college students were randomly assigned to one of five groups: (1) control, (2) placebo control, (3) EMG BFT, (4) meditation, (5) PMR. After baseline measures were obtained subjects were trained in 10 30-minute training sessions and posttested. Comparisons by ANOVAs indicated there was a significant decrease in muscle tension in the EMG BFT and meditation groups and significant decreases in respiration rate in the meditation and PMR groups. No other changes were attributed to treatment.

Biofeedback and relaxation training in the treatment of psychophysiological disorders: or are the machines really necessary?

The literature on the use of biofeedback and various forms of relaxation training in the treatment of psychophysiological disorders was reviewed; special attention was devoted to studies in which biofeedback and some form of relaxation training were compared. Based on this review, we conclude that there is no consistent advantage for one form of treatment over the other with any psychophysiological disorder for which a comparison has been made, e.g., essential hypertension, migraine headaches, premature ventricular contractions, tension headaches, temporomandibular joint pain, asthma, primary dysmenorrhea, and functional diarrhea. For other disorders in which no comparisons have been made (e.g., Raynaud's disease, sinus tachycardia, peptic uclers, and fecal incontinence) biofeedback seems to be a very promising treatment modality.

Biofeedback modification of frontal EMG in normal subjects

We carried out a controlled study on the voluntary control of the frontalis muscle by biofeedback procedures employing 20 normal subjects. Subjects were randomly divided into two groups of 10: (1) the biofeedback group and (2) the control group. Each of the two groups received five training sessions of about 40 minutes' duration each on different days. The results obtained are as follows: (1) In the biofeedback group, mean EMG levels decreased progressively and markedly from 2. 16 muVp-p min the first session to 1.54 muVp-p min in the last session. On the contrary, the control group did not show constant decreases in EMG levels over sessions. (2) The changes in the heart rate did not correlate with the changes in EMG activity. (3) The changes in the respiratory rate correlated with the changes in EMG activity.