A comparison of EMG feedback and alternative anxiety treatment programs

Four cohorts of 40 subjects each were randomly assigned to 1 of 10 treatment conditions utilizing EMG feedback, cognitive monitoring training, systematic desensitization, high expectancy discussion group, or waiting list controls either in isolation or in various combinations. A three-way ANOVA for repeated measures indicated that significant anxiety reductions were experienced in all noncontrol treatment conditions. Treatment groups employing EMG feedback demonstrated significantly greater anxiety decrements on Cattell's IPAT Self-Analysis Form, and baseline frontalis EMG. Adding desensitization or cognitive monitoring to EMG feedback did not produce a more powerful effect than using EMG feedback alone. Sex and age differences were also observed. Some implications are discussed.This research was supported in part by a grant from the Medical Services Research Foundation of Alberta.     

A comparison of frontal EMG biofeedback and neck EMG biofeedback in the treatment of muscle-contraction headache

EMG biofeedback from the frontal area (FFB) was compared to EMG biofeedback from the neck (NFB) in the treatment of chronic muscle-contraction headache. Both treatment groups (N=10) evidenced significant decreases in reported headache activity, with the NFB group also significantly reducing medication consumption. An analysis of EMG changes suggested that subjects were able to produce large within-session changes in EMG activity during initial sessions, with the major effect of additional training being an increase in speed with which these changes occurred. In neither group, however, did changes in EMG activity correspond closely to changes in reported headache activity.     

Contingentvs. noncontingent EMG feedback and hand temperature in relation to anxiety and locus of control

This study was designed to measure the effects of contingent and noncontingent EMG feedback on hand temperature, anxiety, and locus of control. Two groups of six subjects each were selected on the basis of high test-anxiety scores. The groups participated in a reverse design study in which Group 1 received five sessions of contingent EMG feedback followed by five sessions of noncontingent feedback. Group 2 received noncontingent feedback followed by contingent feedback. Results indicate a significant order of treatment effect. Subjects who received contingent feedback first produced lower EMG readings, lower test-anxiety scores, and higher hand temperatures during noncontingent feedback sessions. Receiving noncontingent feedback first may actually have interfered with utilizing contingent feedback.     

Contingent vs. noncontingent EMG feedback and hand temperature in relation to anxiety and locus of control

This study was designed to measure the effects of contingent and noncontingent EMG feedback on hand temperature, anxiety, and locus of control. Two groups of six subjects each were selected on the basis of high test-anxiety scores. The groups participated in a reverse design study in which Group 1 received five sessions of contingent EMG ffedback followed by five sessions of noncontingent feedback. Group 2 received noncontingent feedback followed by contingent feedback. Results indicate a significant order of treatment effect. Subjects who received contingent feedback first produced lower EMG readings, lower test-anxiety scores, and higher hand temperatures during noncontingent feedback sessions. Receiving noncontingent feedback first may actually have interfered with utilizing contingent feedback.     

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<.05) but that alternative forms of muscle relaxation, while effective, did not reach statistical significance.     

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, differences 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.     

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.     

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.This research was supported by Ohio University Research Grants No. 9147 and No. 9155 to the first author.     

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.     

The use of EMG feedback in the treatment of a severe case of blepharospasm

In this case report, a 50-year-old female with a chronic blepharospasm (spasmodic winking) around both eyes was treated with 17 sessions of electromyographic (EMG) feedback. EMG level and spasm frequency were monitored during baseline, placebo, and feedback treatment sessions. There was a marked decrease in both EMG level and spasm frequency, which generalized to her everyday life. Improvement was maintained at a 4-month follow-up.     

Effects of EMG and thermal feedback training on tinnitus: A case study

This case report describes a patient who exhibited the usual complaints of frustration, annoyance, and lack of sleep associated with severe tinnitus. After 2 months of weekly biofeedback sessions along with home training with a portable thermal biofeedback unit, the patient was relieved of the psychological symptoms associated with the tinnitus. A 1-year follow-up demonstrated that the patient remained complaint-free of psychological symptoms although the subjective loudness of the rining was judged to be the same as at the onset of the tinnitus. The results indicate that biofeedback is a useful procedure in the treatment of severe tinnitus.Tallahassee Pain and Stress Management Institute     

EMG feedback for the treatment of upper-extremity dysfunction: can it be effective?

This paper examines the application of EMG feedback for upper-extremity dysfunction secondary to neurologic injury. A rationale for the use of EMG feedback to enhance rotational components of upper-limb movement, train recruitment of the prime movers, and promote inhibition of motor responses that interfere with efficient and effortless movement is presented. Specific strategies that can be used to reinforce functional movement patterns are elaborated. A case study illustrating the application of the feedback strategies is provided. Despite sensory, perceptual, and cognitive impairments, a 53-year-old left hemiplegic obtained significant clinical upper-limb functional gains when given EMG feedback in conjunction with occupational therapy.     

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 ( 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 2×3 (treatment×phase) split-plot factorial design, indicate a highly significant overall treatment effect (F=19.32,p<.001). There was no significant difference between treatments (F=.47) and no significant interaction effect (F=1.74).     

The effects of EMG feedback training during problem solving

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.     

The effect of stressful life events on EMG biofeedback and relaxation training in the treatment of anxiety

The present study evaluated the effect of frontal EMG biofeedback and relaxation training on a group of 20 anxious patients experiencing stressful life events. The patients were divided into two groups, high and low in stress, based on their life change score on the Recent Life Changes Questionnaire. Patients were evaluated at pre, post, and 6-week follow-up. Treatment consisted of 10 sessions of biofeedback-assisted relaxation. Results indicated that the high stress group showed pre to post changes on anxiety, depression, symptoms, and EMG, while low stress showed no change. Post to follow-up comparisons showed maintenance of improvement for the high stress group and no change for low stress. From pre to follow-up assessment, the high stress group showed significant changes. Both groups reported internal attributions following biofeedback and relaxation training. The high stress group attributed their improvement to the belief they were in control of their minds and bodies, while the low stress group most frequently reported the effort put into the task. The results indicate support for a cognitive explanation for some of biofeedback's effects.     

The use of EMG feedback and progressive relaxation in the treatment of a woman with chronic back pain

In this systematic single-case study, a 71-year-old white female with chronic back pain and paravertebral muscle spasm was treated with 17 sessions of electromyographic (EMG) feedback, with recording site just below the right inferior scapular angle. Progressive relaxation practice was also employed. EMG level was monitored during baseline, treatment, and follow-up phases. Backaches were recorded by the subject on a daily basis. There was a marked decrease in both EMG level and frequency of backaches, as well as an increase in activities at home. Improvement was maintained 12 weeks after the last treatment session.     

Reduction of stuttering by young male stutterers using EMG feedback

A clinical program was designed in which male stutterers (age 10–14 years) were trained to reduce speech muscle tension by application of electromyograph (EMG) feedback. The program was designed (a) to reduce nonspeech EMG activity of facial muscles involved in speech, (b) to use this skill for control of muscle EMG activity while speaking, (c) to maintain the physiological EMG activity reduction with behavioral self-control techniques. Three subjects were treated on a single-subject ABCD baseline design, with an ABABAB reversal design within the treatment (B) phase. EMG feedback was shown to reduce stuttering in the clinic. After maintenance techniques were taught, stuttering was shown to have reduced 60–80% in the home environment while speech rate remained constant or increased. A 9-month follow-up showed that the improvement produced in treatment was continuing.     

The use of EMG feedback and progressive relaxation in the treatment of a woman with chronic back pain.

In this systematic single-case study, a 71-year-old white female with chronic back pain and paravertebral muscle spasm was treated with 17 sessions of electromyographic (EMG) feedback, with recording site just below the right inferior scapular angle. Progressive relaxation practice was also employed. EMG level was monitored during baseline, treatment, and follow-up phases. Backaches were recorded by the subject on a daily basis. There was a marked decrease in both EMG level and frequency of backaches, as well as an increase in activities at home. Improvement was maintained 12 weeks after the last treatment session.     

A comparison of direct blood pressure feedback and electromyographic feedback on the blood pressure of normotensives

Groups of 20 normotensive subjects were assigned to one of three conditions to help them lower their blood pressure: (1) intermittent visual feedback of blood pressure; (2) continuous analogue auditory feedback of frontal EMG; (3) an instructed, no-feedback condition. Both groups receiving feedback showed greater within-session lowering of systolic blood pressure than the no-feedback control group. Although the group receiving intermittent visual feedback of blood pressure lowered blood pressure more than the EMG feedback group at the first session, in three subsequent sessions, the two feedback groups did not differ.