Change mechanisms in EMG biofeedback training: cognitive changes underlying improvements in tension headache

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.

Chronic back pain and rheumatoid arthritis: predicting pain and disability from cognitive variables

Cognitive-behavioral models of chronic pain emphasize the importance of situation specific as well as more general cognitive variables as mediators of emotional and behavioral reactions to nociceptive sensations and physical impairment. The relationship of situation-specific pain-related self-statements, convictions of personal control, pain severity, and disability levels was assessed in samples of chronic back pain and rheumatoid arthritis patients. Both the more general and the situation-specific sets of cognitive variables were more highly related to pain and disability than disease-related variables. This association was found in the back pain patients who displayed only marginal levels of organic findings as well as the rheumatoid arthritis sample who had a documented basis for their pain. The combination of both situation-specific and general cognitive variables explained between 32 and 60% of the variance in pain and disability, respectively. The addition of disease-related variables improved the predictions only marginally. These results lend support to the importance of cognitive factors in chronic pain syndromes.

Pain greater than pain behaviors: the utility and limitations of the pain behavior construct

A great deal of attention has been given to the importance of learning factors in communications of pain and suffering--pain behaviors. The concept of pain behaviors has served a heuristic function, however, there remain a number of important questions to be answered regarding the assessment and conceptual limitations of the construct. These concerns and questions must be acknowledged if the construct is to be of use in enhancing our understanding of chronic pain syndromes and to be employed in treatment. Current conceptualizations of pain behaviors are examined and methods of assessing pain behaviors are evaluated. The validity and utility of the construct and its limitations are discussed. It is concluded that failure to consider psychosocial, psychophysiological, and medical-physical factors may lead to an inadequate understanding of the patient and results in inappropriate treatment interventions. Suggestions for refined understanding of the scope of the construct are provided.

Specific and nonspecific effects of EMG biofeedback

This study investigated the effects of performance feedback and EMG biofeedback on perceptions of the "self" (i.e., self-esteem, self-control, self-efficacy, and locus of control) as well as on a self-control behavior (study skills) the subjects performed outside the laboratory. Forty-seven college students were randomly assigned to one of four groups in a 2(high and low success feedback) x 2(true and false EMG biofeedback) factorial experiment with repeated measures. All of the participants received four sessions of EMG biofeedback, and later they were asked to self-monitor their study habits for 2 weeks. Results showed that the self-esteem measure and perceptions of study skills improvement were differentially affected by success feedback but unrelated to the true or false EMG manipulation. Shifts toward an internal locus of control and perceptions of improved self-control were also noted, but they were independent of the subjects' group membership. Implication of the results are briefly discussed.

Client variables and the behavioral treatment of recurrent tension headache: a meta-analytic review

Meta-analysis revealed that in studies evaluating behavioral treatments for tension headaches, the treatment outcome has varied with the client samples (e.g., age, gender, referral source) that have been used but not with the treatment procedures (e.g., type of behavioral intervention, length of treatment, whether or not efforts were made to facilitate transfer of training) or the research designs (e.g., internal validity, explicitness of diagnostic criteria) that have been used. Mean client age proved the best predictor of treatment outcome, accounting for 30% of the outcome variance following behavior therapy. Significantly poorer outcomes have also been reported in recent studies than were reported in early studies. These findings suggest that outcomes obtained with behavioral interventions have been less dependent upon the treatment variables that have been the primary focus of research attention than upon characteristics of client samples and behavioral interventions may be less effective in reducing headache activity than has previously been assumed.

The role of self-efficacy expectancies in the prediction of pain tolerance

The association of self-efficacy expectancies with pain tolerance on the cold pressor test was examined during treatment conditions of setting quotas alone and in conjunction with monetary reinforcement and placebos in 64 college volunteers. It was found that quota setting was an effective means of increasing cold pressor pain tolerance. The addition of monetary reinforcement of quota achievement did not enhance performance, while the addition of a placebo decreased the effectiveness of quota setting. Self-efficacy expectancies were significantly correlated with pain tolerance times and were better predictors of tolerance than pain ratings. Self-efficacy expectancies and pain tolerance times at treatment were both found to predict 1 week follow-up performance.

Long-term efficacy of EMG biofeedback for chronic rheumatic back pain

Short-term effects of EMG biofeedback for chronic rheumatic back pain have been documented, however, the long-term efficacy of this treatment modality has not yet been established. Twenty-two patients of an original sample of 24 patients who participated in a treatment outcome study [6] were followed up 2.5 years after they had been treated with either EMG biofeedback, pseudotherapy, or conventional medical treatment alone. The results indicate that patients treated with EMG biofeedback maintained beneficial effects and differ significantly from the control groups both on behavioral and cognitive responses to the pain, but not global pain intensity ratings. These data support the long-term utility of biofeedback for chronic rheumatic back pain.

A review and clinical perspective on the use of EMG and thermal biofeedback for chronic headaches

A comprehensive survey of EMG and thermal biofeedback for chronic muscle contraction and migraine headaches is presented. The studies done to date suggest a high degree of short-term efficacy of biofeedback, which has been maintained on long-term follow-ups. While comparisons of biofeedback with relaxation generally have shown approximately equivalent effectiveness, the two forms of therapy may be differentially effective with different subjects. Attempts to correlate EMG and/or thermal parameters with headache parameters generally have failed to produce significant results, particularly in more recent and better-controlled studies; however, numerous technical and procedural difficulties have obscured meaningful interpretation of physiological data. Results with pseudofeedback do suggest a likely specific contribution of frontalis EMG to muscle contraction headaches, at least for some subjects. Comparable evidence for a specific contribution of thermal parameters to migraines is almost totally lacking. Clinical outcome research suggests that biofeedback in general may be more effective in younger anxious subjects who show no chronic habituation to drugs, and that there is little apparent benefit from repeating biofeedback for more than about 12 sessions maximum. Three broad areas for subsequent research are suggested: longitudinal study of EMG and thermal parameters in a naturalistic setting, specification of processes critically involved in biofeedback, and clinically relevant comparative outcome research with biofeedback and alternative therapies.

Physiological changes after biofeedback and relaxation training for multiple-pain tension-headache patients

This paper is concerned with the psychophysiology of "muscle-contraction" headaches in a group of Compensation patients suffering from multiple pain problems in addition to headaches. A total of 55 of these patients were divided into 4 groups which received frontalis EMG biofeedback, relaxation training, combined biofeedback-relaxation training, or no treatment. Differences were observed among the 3 experimental treatments and the control group with respect to headache changes, but there were no differences among groups with respect to the changes observed in four underlying physiological responses as a function of time or practice. While the subjects who showed the largest changes in headache characteristics were those who exhibited the largest decreases in frontalis EMG, these were also the subjects whose initial frontalis EMG levels were the highest. It is concluded that, in keeping with a growing literature, the link between frontalis EMG and "muscle-contraction" headaches is a tenuous one and that the changes brought about in headache symptomatology through biofeedback or relaxation training are most likely attributable to a generalization of feelings of mastery over the environment or of self-efficacy brought about in the subjects through apparent success at the task.

Biofeedback control of migraine headaches: a comparison of two approaches

In order to assess the relative effectiveness of finger warming and temporal blood volume pulse reduction biofeedback in the treatment of migraine, 22 female migraine patients were assigned to one of three experimental conditions: temporal artery constriction feedback, finger temperature feedback, or waiting list. Biofeedback training consisted of 12 sessions over a 6-week period. All patients completed 5 weeks of daily self-monitoring of headache activity (frequency, duration, and intensity) and medication before and after treatment. Treatment credibility was assessed at the end of Sessions 1, 6, and 12. Results showed that temporal constriction and finger temperature biofeedback were equally effective in controlling migraine headaches and produced greater benefits than the waiting list condition. Power analyses indicated that very large sample sizes would have been required to detect any significant differences between the two treatment groups. No significant relationships were found between levels of therapeutic gains and levels of thermal or blood volume pulse self-regulation skills. Likewise, treatment outcome was not found to be related to treatment credibility. Further analyses revealed that changes in headache activity and medication were associated with changes in vasomotor variability. Because blood volume pulse variability was not significantly affected by biofeedback training, questions about its role in the therapeutic mechanism are raised.