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.We would like to express our appreciation for the contributions the following people made to this project: Drs. Barry Smith, Robert Steele, Agnes Hartfield, Jeffrey Barth, Althea Wagman, and the late Harold Weiner; Earl Downs and the participating staff at Springfield State Hospital Center; and Robert Kline and Michael Kelley, who performed the data analyses. This research was supported in part by a grant from the Computer Science Center at the University of Maryland.     

Relaxation and subjective estimates of muscle tension: Implications for a central efferent theory of muscle control

The relationship of “awareness of muscle tension” to depth of relaxation was explored. In one experiment, accuracy of forearm flexor control was assessed using the psychophysical method of magnitude production, and depth of flexor relaxation was measured using the integrated EMG before and after EMG biofeedback training. No consistent relationship between motor-control accuracy and depth of relaxation was found. A second, similar experiment with frontalis showed increased accuracy of frontalis control with deeper relaxation. Accuracy of passive, verbal judgments of spontaneous frontalis tension fluctuation exhibited no clear relationship with depth of relaxation. It was concluded that forearm flexor and frontalis may be under the control of distinct mechanisms, and that afferent information probably contributes to the control of neither muscle. Three structural theories of the control mechanisms were considered, and one depending on the central monitoring of efferent outflow(rather than afferent inflow) seemed most compatible with the frontalis data. Both flexor and frontalis data could be accounted for by a two-phase scheme combining central outflow monitoring with the monitoring of mental contents for arousal value at very low muscle tension levels.     

Is group progressive relaxation training as effective with hyperactive children as individual EMG biofeedback treatment?

This study examined whether group progressive relaxation training was as effective as individual EMG biofeedback training in facilitating the academic achievement and self-control of 45 hyperactive elementary school children. Academic achievement was assessed with the Gates-MacGinities Reading Tests, and self-control was measured with the Nowicki-Strickland and the Teacher Rating scales. Eight sessions were scheduled at weekly intervals. Progressive relaxation was conducted in groups of seven or eight and was induced with a commercial audiocassette program. EMG training augmented frontalis biofeedback with those taped exercises. A placebo group listened to taped children's stories. Multivariate analysis of variance indicated no significant differences among the three contrast groups when all dependent variables were considered together. However, univariate F values and discriminant analysis disclosed locus of control to be significantly more internal for the progressive relaxation condition. Also, differences between the two relaxation and the placebo groups, though not statistically significant, were all in the expected direction. While the relative efficacy of group progressive relaxation could not be established conclusively, the data appeared sufficiently positive to warrant further investigation of this cost-effective prospective intervention.The opinions expressed by the authors are not necessarily those of their respective institutions.     

Finger pulse amplitude and frontalis EMG biofeedback effects of single- and two-system training.

The relationship between finger pulse amplitude (PA) and frontalis EMG was studied first by looking at general physiological changes accompanying successful bidirectional PA control. Seven successful subjects were then asked to produce two patterns of PA and EMG (PAincEMGdec and PAdecEMGdec) while receiving both PA and frontalis EMG biofeedback. Results indicate subjects can easily produce the differentiation pattern of PAdecEMGdec but cannot produce the integration pattern of PAincEMGdec. These rather paradoxical results may indicate subjects were using an "attentional" rather than "arousal" strategy for controlling PA and have implications for the use of peripheral vasomotor training as a general relaxation technique.     

Effects of relaxation and/or biofeedback training upon hip flexion in gymnasts

In Study I 10 male gymnasts were matched for hip flexibility and then randomly placed in either a control or a biofeedback group. After warm-up exercises, the control group practiced self-relaxation while the biofeedback group received EMG feedback from the hip extensors. Both groups significantly improved hip flexion from trial 1 to trial 9. The biofeedback group significantly improved more quickly across trials, as measured by slope analysis, than the control group. In Study II 15 female gymnasts were matched for flexibility then randomly placed in control, relaxation, or biofeedback plus relaxation groups. Each gymnast completed STAI (A-state), warm-up exercises, and a 10-minute treatment and was then tested for hip flexion. The control group received no treatment, the second group received modified progressive relaxation, while the last group received relaxation and EMG hip extensor feedback. All groups significantly improved from trial 1 to trial 8 with no one group superior to the others. There were no significant differences among groups for rate of improvement across trials. There were no significant correlations among state anxiety, age, and flexibility measures.This work was funded in part by a Canada Council Leave Fellowship and Research Grant. Appreciation is extended to Ole Pedersen, Frank Circelli, and Dave Steeper for the data collection in the first study. The authors also extend their thanks to the gymnasts and coaches from York University, Toronto, and the Aztec Gymnastics Club, San Diego.     

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 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 training in frontalis muscle relaxation and enhancement of belief in personal control

The hypothesis that biofeedback training in frontalis muscle relaxation increases beliefs in internal (personal) locus of control was tested. Subjects were divided into two groups (internals and externals) based on Mirels' (1970) factor analyzedpersonal control subscale of Rotter's (1966) I-E Scale. Internal and external subjects were assigned randomly to one of three conditions: biofeedback (BF), false feedback (FF), or no feedback (NF). All subjects were measured on frontalis electromyographic (EMG) activity. Training consisted of three sessions spaced 1 week apart. Each session was comprised of a 5-minute baseline (nonfeedback) trial followed by a 20-minute experimental session. After each experimental session, subjects completed a questionnaire which assessed the extent to which they attributed their EMG performance to personal and environmental sources. After three sessions, subjects were posttested on the I-E Scale. Results indicated that subjects receiving BF reduced their EMG activity more than did subjects in either the FF or NF conditions, and this effect was maintained across all three sessions. Subjects who received BF shifted toward internal personal locus of control from pre- to posttesting, whereas no such change was found for either FF or NF subjects. Also, the relationship between BF training and change in personal locus of control was mediated by subjects attributing their EMG reduction more to personal effort than to properties of the task. Results are discussed in terms of the importance of contingent feedback as a determinant of cognitions of control.     

Ocular and stabilization feedback: an evaluation of two EMG biofeedback control procedures

This study evaluated the adequacy of two novel EMG biofeedback control procedures. During a single training session, 36 subjects received either contingent EMG feedback from the frontal region (Veridical), contingent feedback for vertical eye movements (Ocular), or a feedback condition where the signal increased with deviations in any direction from baseline EMG levels (Stabilization). The results supported the use of Ocular but not Stabilization feedback as a control procedure in frontalis EMG biofeedback studies. Ocular feedback did not produce reductions in frontalis EMG but did lead to changes in subjective measures of nonspecific treatment effects that were at least comparable to those obtained with Veridical feedback. Stabilization subjects produced small but significant reductions in EMG, felt the most bored as a result of their feedback training, and were the most likely to rate themselves as having received false feedback. The implications of attribution theory and multiprocess relaxation theory for the evaluation of nonspecific treatment effects are discussed.     

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.     

Effects of EMG biofeedback on diabetes

A case is described in which a juvenile-onset insulin-requiring diabetic was given frontalis EMG biofeedback. For 6 years prior to biofeedback training, the subject had been healthy and stable on 22–24 units regular insulin injected once daily. During 8 weeks of standard feedback training for relaxation of frontalis muscle activity, the subject twice reduced her daily insulin dosages. At the end of 8 weeks, the subject was receiving 17–18 units regular insulin daily but was still unstable, sometimes being hyperglycemic, sometimes hypoglycemic. Because of disturbing symptoms associated with this instability, biofeedback was discontinued for 6 months, at which time the subject was again healthy and stable on the equivalent of 18–19 units regular insulin daily. After this period, biofeedback was again given for 1 week, but the subject again became highly unstable and biofeedback was permanently stopped. Caution is suggested when dealing with diabetic patients.     

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.     

Feedback delays and relaxation expectancies in EMG biofeedback

The use of noncontingent feedback controls in studies of the efficacy and process of electromyographic (EMG) biofeedback may yield results confounded by differential expectancies for relaxation. Furthermore, the role of expectancies in producing psychological and physical relaxation as well as reducing muscle activity is unclear. This study investigated the effects of feedback delays and induced relaxation expectancies on EMG activity and experienced relaxation. One hundred four non-clinical subjects participated in one auditory frontal EMG biofeedback training session. Subjects were assigned to one of four computerized feedback delay conditions (0.0037, 0.7493, 2.2481, 6.7444 s) and to one of two relaxation expectancy conditions (positive or negative). During 20 minutes of biofeedback training, all groups decreased frontal activity. Feedback delays interacted with training epochs in affecting EMG; the longest delay group reduced frontal activity more slowly than the shortest delay group during training. Positive relaxation expectancies produced greater experienced relaxation than did negative relaxation expectancies. Instrumental and expectancy factors in EMG biofeedback appear to operate independently of each other by reducing physiological activity and producing psychological relaxation respectively.     

Stress reduction treatment of severe recurrent genital herpes virus

Four individuals with high-frequency recurrences of genital herpes virus of at least 2 years' duration were treated with two behavioral stress-reduction treatments. Subjects were given 10 weekly sessions of frontalis EMG biofeedback (2 subjects) or progressive muscle relaxation treatment (2 subjects). Presession and postsession frontalis EMG measures were recorded for all subjects across treatment. Outcome was measured by daily and weekly symptom charting mailed in weekly over 6 months, or by telephone interview after 6 months. Results demonstrated substantial improvement in reported symptoms with both treatments. Relaxation treatment resulted in a 66% and 100% reduction in frequency of recurrences. Frontalis EMG biofeedback resulted in a 72% and 7% reduction in frequency of recurrences. Follow-up at 1-year posttreatment showed that treatment effects were maintained by one subject, partially maintained by two, and reversed in one subject. The need for controlled investigation is emphasized.     

Ocular and stabilization feedback: An evaluation of two EMG biofeedback control procedures

This study evaluated the adequacy of two novel EMG biofeedback control procedures. During a single training session, 36 subjects received either (1) contingent EMG feedback from the frontal region (Veridical), (2) contingent feedback for vertical eye movements (Ocular), or (3) a feedback condition where the signal increased with deviations in any direction from baseline EMG levels (Stabilization). The results supported the use of Ocular but not Stabilization feedback as a control procedure in frontalis EMG biofeedback studies. Ocular feedback did not produce reductions in frontalis EMG but did lead to changes in subjective measures of nonspecific treatment effects that were at least comparable to those obtained with Veridical feedback. Stabilization subjects produced small but significant reductions in EMG, felt the most bored as a result of their feedback training, and were the most likely to rate themselves as having received false feedback. The implications of attribution theory and multiprocess relaxation theory for the evaluation of nonspecific treatment effects are discussed.This research was supported in part by grants from the National Institutes of Health (AM31500) and the Robert Wood Johnson Foundation. Portions of this research were presented at the Sixth Annual Meeting of the Society of Behavioral Medicine, New Orleans, March 1985.     

Change Mechanisms Associated with Combined Relaxation/EMG Biofeedback Training for Chronic Tension Headache

Therapeutic mechanisms hypothesized to underlie improvements in tension headache activity achieved with combined relaxation and eleclromyographic (EMG) biofeedback therapy were examined. These therapeutic mechanisms included (1) changes in EMG activity in frontal and trapezii muscles, (2) changes in central pain modulation as indexed by the duration of the second exteroceptive silent period (ES2), and (3) changes in headache locus of control and self-efficacy. Forty-four young adults with chronic tension-type headaches were assigned either to six sessions of relaxation and EMG biofeedback training (N = 30) or to an assessment only control group (N = 14) that required three assessment sessions. Measures of self-efficacy and locus of control were collected at pre- and posttreatment, and ES2 was evaluated at the beginning and end of the first, third, and lost session. EMG was monitored before, during, and following training trials. Relaxation/EMG biofeedback training effectively reduced headache activity: 51.7% of subjects who received relaxation/biofeedback therapy recorded at least a 50% reduction in headache activity following treatment, while controls failed to improve on any measure. Improvements in headache activity in treated subjects were correlated with increases in self-efficacy induced by biofeedback training but not with changes in EMG activity or in ES2 durations. These results provide additional support for the hypothesis that cognitive changes underlie the effectiveness of relaxation and biofeedback therapies, at least in young adult tension-type headache sufferers.     

Stress reduction treatment of severe recurrent genital herpes virus

Four individuals with high-frequency recurrences of genital herpes virus of at least 2 years' duration were treated with two behavioral stress-reduction treatments. Subjects were given 10 weekly sessions of frontalis EMG biofeedback (2 subjects) or progressive muscle relaxation treatment (2 subjects). Presession and postsession frontalis EMG measures were recorded for all subjects across treatment. Outcome was measured by daily and weekly symptom charting mailed in weekly over 6 months, or by telephone interview after 6 months. Results demonstrated substantial improvement in reported symptoms with both treatments. Relaxation treatment resulted in a 66% and 100% reduction in frequency of recurrences. Frontalis EMG biofeedback resulted in a 72% and 7% reduction in frequency of recurrences. Follow-up at 1-year posttreatment showed that treatment effects were maintained by one subject, partially maintained by two, and reversed in one subject. The need for controlled investigation is emphasized.The authors thank Stephen Ritz for his contribution to this study.     

Effects of Relaxation Training on Glucose Tolerance and Diabetic Control in Type II Diabetes

The present study examined the effects of progressive relaxation training and EMG biofeedback on acute glucose disposal in diabetic subjects, as measured by glucose tolerance and three other measures of diabetic metabolic control. Twenty subjects with non-insulin-using Type II diabetes took part in progressive relaxation training and EMG biofeedback in a pre-post treatment versus wait-list experimental design. Treatment effects were assessed on glucose tolerance along with three measures of diabetic control: fasting blood glucose, two-hour postprandial blood glucose, and fructosamine. Stress reduction and relaxation was assessed with two physiological measures and two subjective questionnaires. The training program produced significant reductions in stress, as measured by State Anxiety, and significant changes in physiological measures of muscle activity and skin conductance compared to the control condition. However, no changes were found in glucose tolerance (while practicing relaxation) nor in any of the three measures of general diabetic metabolic control. The major implication of this study is that relaxation training does not appear to directly improve diabetic control in mildly stressed non-insulin-using Type II diabetic patients.